A few other wild facts here; 3" exhaust, with both wastegates re-routed back in, restrictive Apexi N1 catback( snorkels down to 2.25" tubing at the twin catback), intercooler isn't that big & its tube and fin, intercooler piping is ovaled down 2.5". Would love to see those get changed, but Rob needs to focus on the 12 rotor and pikes peak.
I'm not a rotary guy or mechanic. I tinker on NA 4 bangers. But i never miss a video of Robs. The only Utuber that explains engines, cncing, wiring, suspension setups, welding. Well everything to a understandable degree. Clear, concise. He just make u think out of the box and reasons for the way things work. Hats off bro.
Rob is awesome, but there are many other youtubers that explain stuff in such a way that even a moron like me can understand it. Al from The Skid Factory, Rich from Deboss and Nik & Richard from Bad Obsession Motorsport come to mind. edit: and if you think that the 4 rotor has been long in the making, then check out Project Binky.
@@pirkkaruuska5766 i watch skid factory, great also for turbos and alike. been a while since i watch binky and the boys at Bad Obs...all great, but Rob is soothing..lol
Shout out to the J man for the editing on this video, bouncing around from different shoots to get all of robs wild details in a smooth chronological explanation is no small feat ❤
I work in tech, and the entire time you're talking about the Trigger, my brain kept hearing "It was DNS... it's always DNS." Really loved the breakdown of fuel/air moving through the engine. I don't tune engines or anything, it was just awesome seeing it explained that way.
There are only a couple TH-camrs that I’m excited every single time they upload. Rob is by far the most exciting even when it’s something small. You keep my dream alive while not being able to complete it myself due to life. Thank you Rob for everything you do for us! We appreciate it all!
The only other automotive TH-camr/builder/racer that explains this kind of stuff in such a detailed and bottom line way aside from Rob, in my opinion, is Steve Morris. I’m pretty sure many people would agree in saying that Rob Dahm is the Steve Morris of rotary engines.
Not by a long shot! I love Rob's stuff, his videos, his builds ect. but come on. One is like the ultimate unlimited budget ADHD hobby man who's doing amazing things. The other is an all time legend who's won so many championships its hard to keep track of, and creates engines from scratch that go out and win countless local events. When Rob starts sell us his own design, all billet rotaries then maybe he'll be like 1/8th of Steve Morris. I'm not hating at all, just looking at the facts.
@@bennyb.1742 Don’t get me wrong, I fully agree with you. Im not trying to take away from Steve Morris or hold Rob Dahm up like he is a god or anything but when you look at both of them on the ground floor, their are quite similar. Steve Morris has poured his entire being into learning everything he can, building an absolute empire from nothing, testing his engines and parts relentlessly to find the weak point, then making revision after revision to produce a rock solid product that he is proud to put his name on and stand behind 100%. All while never trying to bs you, show you the raw data and explain absolutely everything. Yes Steve Morris is at the top level that not many people will ever get close to. Rob holds the exact same core values that Steve does. Rob lets his data do the talking the same as Steve. Rob is on the ground floor of building his empire. They both started from pretty much nothing with a passion for automotive and they are chasing their dreams never giving up and never trying to bs anyone. They let the data do the talking. I apologize for this being so long winded, I wanted to explain in more detail why I see them as being fundamentally equals when you remove all the awards and fame, (that have been rightfully earned) and see them as dedicated mad scientists with a burning passion.
I'm someone that have been following Rob since 2020, I initially looked at him a bit as "lets see how far this fool will get", like this guy knows nothing but in a friendly way. Today, I wanna say that this video has been the best one Rob has ever released, very informative, very clear, very knowledgeable. I can say today that I'm impressed and in a way "proud" of Rob progress in his Dorito career. Thank you Rob for sharing your knowledge and learnt lessons with the community.
Blessings Rob bro, i have an s4 block since 2022 dyno test with 605whp, almost used daily, p/s, a/c. Completely stock s4 intake manifold and throttle, it cruise like stock and handles 25psi with snow meth kit. My 605whp went al 6,480 rpm. And 496lbs torque. Stock heavy flywheel, 1050 inyector dynamic primaries, 2200 original bosch secondarys, microtech lt10c management, precision turbo 7675 with .96 a/r. And this is a small part of the ingredients. Thanks Rob!! Blessings bro! Rotary for life. Puerto Rico 🇵🇷 love rotarys.
I’m a 4g63 (Evo) and now a ( 740hp) 4.7 TT Mercedes guy. Been at it for 25 years. I’ve watched your videos for years now and love how humble you stay and yet how knowledgeable you continue to become and grow. You’re the only YT’r that I feel like is a completely relatable person and one I keep cumming back to (har har har) Keep at it Rob .
This video is so helpful for an FC S4 owner. I watch all of Rob's videos but pay special attention the these ones. This gives me hope that I can make my FC an absolute rocket when it get a restoration/rebirth ❤ your work and keep it up.
Check out the Motul Micro oil for premixing, it’s made for R/C nitro engines and may be suitable for your needs. Also yes, decent/oversized even, wiring is always needed for fuel pumps, overlooked many times. Going from the supplied tefzel to 6mm copper cable for that 525 Walbro pump let us remove 10% fuel over the whole map, sounded higher pitched when running etc.
The production quality on each of these videos is insane considering it’s just another TH-cam video. Definitely setting the standard for quality when it comes to automotive videos👏🏼
Would consider doing a live stream of a tuning session and kinda just show the process of tuning the car? It would be really informative, especially if you built the whole map from the start. I’ve never seen anyone really do that besides hp academy if you buy it.
If you want to do this from the first stages, it would take many many many hours, probably days doing it in a livestream. You have to dot all your i's and cross your t's before you can do the next step. While you are doing this as fast as you can, you spend many hours checking "mundane things" swapping parts, calculating and such. This is all the ground work required that is required to finally have a good "tuning session" on the dyno. Ask any dyno shop; most people that aren't experienced that show up, get sent home to re-do their prep work without getting much performance to show for it during the session. Just showing the dyno bit without showing everything required to make it successful will be not be an accurate depiction of "the process of tuning the car". Having said all this, doing a series on the road to the dyno session and closing it off with that session would be super awesome.
Rob, I love all of the insane builds from the 3, 4, and 12 rotor but this FC is by far my favorite car of yours. It’s my favorite generation of rx7 and your work on it has been amazing to watch.
I don't know where this shoot sits in the pikes peak run timeline but I really appreciate the explainers you do. Goated not just for rotaries but as a car channel in general.
Sir, super impressed at where your heads at now compared to a few years ago. Learning about how stuff works and learning why it works are not the same thing. This approach on showing why your results are what they are is probably going to net you some real die hard followers. Hopefully they too will also take the time to learn how and why things work the way they do and gets rid of people copying and pasting everyone else's hard work. Glad you have the platform to say this is what the deal is... keep on keeping on🤙
I appreciate the tidbit about the short pulsewidth adder, showing the table. The file I downloaded from ID has percentages, but the table was wanting ms. I initially ignored the "adder" language and thought it wanted the full value to use instead (which is my interpretation of their kb article defining "effective pulse width") but I found that I only needed to take one step to input the additional amount rather than the total. I don't even have a rotary, but just having the screen shown allowed me to do a sanity check.
He is so good at selling you information, and since is for free you just keep wanting more and more... I don't even have a rotary, but it helps you shape your way of thinking and conside things that you could have missed, he is trully a good teacher.
Taking notes for no reason? What that says is, you have nothing in YOUR actual life that you care about as much as you care about a stranger's actual life.
My first car was a 1987 RX7 base model. The apex seals blew and that was the end of the motor. Sadly, no mechanic in the area would touch that car. Being 18 or 19 at the time, I couldn't afford to keep it until I found someone to fix it. I cried when the tow truck came to pick the car up. I'm almost 37 and I still have a massive love for rotaries. I do hope they make a comback one day. I doubt it since the EPA is so strict now. The RX-8 was a good example of what could have been, but sadly those had a lot of premature engine failures.
👍👍First time I've ever heard a tuner mention running softer ignition settings on lower compression engines, especially on E85. All the 90's-2000's turbo JDM cars were low compression and a lot of tuners tend to lean on that ignition curve because its not pinging. But its not making any more power either. But in a piston engine, it does tend to lift the head instead of making power, and yes keep all that heat in the engine.
17:37 Sounds just like someone ranting on SR and RBs, the stock optical Nissan CAS is such a nightmare, causing tons of uncessary and "random" hard to diagnose issues. A good crank trigger just makes the engine feels smooth, solid and responsive. Definitely going to make a custom crank trigger setup for my 13BT2 for my new FB build as well.
I had asked about the injector timing on a previous video, so getting that discussion was awesome, but the timing and lambda tables you use opened up my eyes as well. My 1987 Non-turbo FC is about to cross 100,000 original miles (car sat for 14 years, thanks USAF) I had been running it at 23 degrees across the board, compared to your 17 out of boost, as well as your discussion about how timing in cruse is not that important, am going to have to take a look at it. I've been able to get 32 mpg on flat terrain, but the moment hills start getting involved, I see it drop to around 26. I do not have easy access to a dyno, so had been turning my timing by setting my AFR to 13 across the board, doing several trips while maintaining speed limit at all times. Change entire map 1 degree, record GPS data, and seeing that areas I needed less throttle (car has been converted to a 100% mustang TPS sensor) I figure that using less throttle, means that you are making more power at the flat and hill locations and have been tuning from that kind of data. With your previous video showing how off the front and rear rotors were AFR wise, it also made me wonder about an issue I was getting on overrun where the single O2 sensor I have was jumping up and down, but only in overrun, might be that I am getting stream AFR variations on front and rear as well. I just sent my other car (97 Turbo Miata) engine block in to get it machined, so once I get up and running again, can start ripping into my RX7 and create a turbo system for it.
sadly i dont recall the video but Rob once spoke about fuel and that it has to be either E85 or E100, other fuels have either too high octane or are too junk and cause the rotors to get covered in carbon/dirty. If you watch his other videos youll notice that his rotor faces are even almost shiny looking, like new.
I just had an idea for getting to the bottom of the oem vs aftermarket manifold. We have full power comparisons. Great. Now for the low throttle percentage torque measurements. Process: On the oem plenum Figure out what TPS% the secondary throttle start to open. Let say 20%tps- to avoid the secondaries intruding we should aim for 17%TPS. Now dyno the torque in 3rd gear at 17%tps. For both plenums. I want to see the difference from the higher velocity on just primaries.
Not gonna lie, I've got a lil' old stick Protege that I've been very slowly restoring, but Dahm's got me to the point of seriously considering rotary-swapping my Mazda, maybe in the next few years...
Love the Rob tuning school. I learned on a power fc and switched to an elite 1500. It's an information overload. Would love to see more videos on tuning tips
3:20 you can do the dowel upgrade, but you need guts and a specific tool and patience. You need an expandable reamer (that has the right beach to work on, cause they're not infinitely expanding) and you need some method to make sure you're going in straight. I have, in the past, introduced these reamers in existing holes, un-expanded, and then expanded them slowly, taking just hair shavings off, but you need an even more specific reamer, the gun barrel expandable reamer, which is not only long, but also very accurate across its length. With a regular expandable reamer, you have to use a drill press (a good one) so you can keep going in and out, and average out the losses. edit: oh and you need lots of oil and a good tap wrench. I'm not kidding with the oil. You have to bathe that reamer in it.
Finally someone is actually measuring the air pressures and temps on both sides of the intercooler. Now you mentioned another key item, and that the heat of the exhaust is power. Ok then increase your power two ways at one time, and hows that. Simple wrapping the entire exhaust going to the turbo, and wherever the exhaust is still inside the engine compartment. This does two things, one it does in fact increase the speed of the tubo by suppling more powerful exhaust pressure due to increasing the hot exhaust blasting the turbo thus spinning the compressor wheel faster creating more boost. Secondly, by reducing the temperature inside the engine compartment, and this does two things in itself. Reduces engine soaking as much heat from the heat radiating from the exposed exhaust and the hot side of the turbo that needs a blanket same as exhaust needs wrapping. Which it lowers engine compartment temperature then you reduce heat transfer to the cold intake pipes, and the manifold itself. So why not wrap the cold side too, and help it even more. Win win situation all the way around. Another thought try to make entering and leaving your intercooler dead center, and by doing so, you increase the air flow through it, and reduce the static pressure caused by the restriction caused by frocing air through just a portion of the intercooler. Where as if the intercooler is designed correctly then there's a even flow of air across the entire tube sheet, and the air is allowed to loose more heat to the cooler air moving across the outside of the tube sheet fins
Fuel pumps also work in a way that people don't realize. I have a 7.2 liter that gets around 10mpg...until you drop the pedal to the floor then the pump goes in to truly massive work mode. Do not cheap out or underestimate your fuel demands.
Totally agree with what you are saying and that why I try to get the ambient air into the intake and not air that has passes through the intercooler and or radiator. Also I wanted to know if there was any testing of premix fuel with regard to autoignition temperature. Love your work and the detail that you show us novices. Thank you and your team, keep up the good work.
I've loved the Wankel from the first gen RX-3. It's the "snarl" of the exhaust notes, although I have to say I love the sound of an aggressive cam in a big block V-8 as well! If I had the $$ I'd put a 13B (maybe a 20B) into a jet boat, one of the short keeled river runners that usually run a Rotax rather than a sprint racer.
I also want to know? I had a engine with 300 HP or less and it had rotors that had clearly hit the irons in the exact place that people clearance aka just below the corner seals?? I was told by Rob at pineapple racing to clearance every engine and stud or dowel and Ballance if you can afford it and our racing it??? Idk I'm interested to see what master robs input is????
Side clearencing has nothing to do with hp but more for RPM. Rob is peaking his HP at 7k and letting off at 8.5. If you plan on reving past 8.5k on a regular, then clearancing can help.
On the 3 rotor they arent side clearanced and i can see where they make love to the irons. But i spin that engine up almost to 10k often. like rotaryperfection said if its in the normal power band and under 8700 no worries about it. But high rpm definitely a must
Interesting info on Turblown's upper intake manifold. I know this video is 6 months old, but Rob, have you been given the chance to test out Turblown's lower intake manifold to get the full package? They do put alot of research in the products.
20:00 I think this is the first time I've ever seen someone in the automotive mainstream on youtube talk about non-linear pulse width response. Though I don't have a wankel powered car it makes sense that low rpm operation with big injectors will be even worse than with the 4cyls I was dealing with. When I cut my teeth on tuning my first turbo 4cyl with big injectors and found out most people just ignore it and idle at 12:1 or something ridiculous and run super rich through all low rpm transients to avoid surging and idle hunting and such. I had to characterize my injectors myself through trial and error, I couldn't afford ID or FIC and just had siemens deka or deatschwerks junk back then! I maintain that making power is easy. Making power with back to back WOT runs on the dyno are so simple a monkey can do it, but idling well, cold staring well, not stalling at lights, not bogging when the AC kicks on, not being jerky at partial throttle during transients, getting good fuel economy, that's what separates a good tune from a dyno tune.
I'm learning to build RX-8. I will use electric super/turbocharger, it's the real deal running on 48V lithium battery that works like nitrous surge. What is the safe amount of boost or whp with stock internals? Should i change the rotor using the RX-7 or i can just use aftermarket seal on RX-8 rotors? What other thing should i consider for boosting RX-8?
Appreciate you sharing as always. I am planning my 700hp build currently. Glad you confirmed a lot of what you did. I have a lot of questions I send over if you dont mind. OMP removed? Only pump e85 and no AI? Did you have 4x 2600cc or just 2 secondaries? Looks like a street car. Did you run into any limits with R3 outputs-fuel pumps, fans, etc? I will have to go back and look at your fuel pump setup. I was planning on 2 hellcats, but i see you called that out directly. Lol
OMP removed. i would do omp pulling from a reservoir as an alternative but all my cars premix. 21700s and 2 2600s total on the entire car. R3 isnt for running lights etc so you have the 4 25 amp outputs and a couple half bridge outputs for drive by wire or electric wastegates. I loved the hellcat pumps but they suck down the power massively.
if you don't clearence and balance your rotors, how can you be sure it doesn't make contact with the sideplates at 9-10k. i thought it was a well known problem when making power at those rpms that the rotors wobble and if not clearenced can lead to major damage. if that is caused by something else could you explain by what if you know and why it might be worse to clearence and balance them. thanks in advance.
This is a great video, lots of technical info. 0.81 Lambda at 20psi boost sounds aggressive for a turbo rotary IMHO, I'm guessing this was on E85 and not pump fuel?
I use lucus 2 stroke motor oil at 2oz per gallon and have no problem with smoking and the inside of the motor was super clean when I rebuilt it due to a oil pressure spike
Wow man what a video, Im blown away on your info, editing and content of said info. I will definitely save this for the future when I do this one day keep going man if you keep going in thid direction like you did with this video you will be huge but that's not the point! Everybody deserves to learn this info about tuning so everybody could be better❤❤❤❤❤❤❤❤❤❤❤❤🎉
Watching this video really makes me want to build something with a 13b now lol Hey Rob, when are you going to build a big power supercharged rotary? I've always been curious about what the limits are as far as supercharger size(and resulting parasitic drag) vs engine size. Would be pretty interesting to see what a 13b does with like a 3.0l Whipple twin screw or a Vortech YSi centrifugal attached to the crank.
I can put this video on my preteen niece's random playlist & it will still be easy and enjoyable edu-creation walkthrough, prop's to the legend himself!
This feels like college again.. love all the information. Definitely gonna be rewatching this like 12 times. I have the turbo, 4 port manifolds, fuel system, intercooler system, and Haltech 1500 for my 1988 GTU (6 Port NA.) Is there any opinion on the IGN-1A coils vs LS Coils in terms of cost/performance/availability. The biggest hurdle for me is it's a perfectly running 70k mile 13B, trying to be the least intrusive to the keg itself. I honestly just want to make 300hp!
Excellent tech vid. I configured the short pulse width adder data for my ID injectors, but the part that throws me off is that the right most value in the ID provided data is not 0. So does that mean its carrying out that last value across all greater pulse widths? If so, doesn't that just mean you should adjust the injector flow capability chart? 19:45
What are you doing to keep the "fireballs" on decel to a minimum? Also, Awsome video, you broke down some pretty complex ideas fairly simply and showed the numbers! Bravo!
That's what you want to see from an intake upgrade on any engine. More power at the same boost but more importantly less boost when you max out the turbo. The important thing to take away from that is a turbo isn't limited by boost it's limited by airflow. When the same amount of airflow has less resistance you make less boost. Too many people ask "how much boost?" without understanding what it really entails. A stock 5.3 ls at 25 lbs of boost is gonna make a lot less power than the same 5.3 with nice heads/cam/intake/turbo system etc. with the same displacement.
You'll enjoy watching robs last video (I think..) he's definitely said exactly that in one of the recent ones. Almost verbatim 😅 thought you were quoting. Enjoy the validation!
@@blitzroute66 lol he did didn't he? I legitimately forgot about that. It's just something I find myself explaining a lot. I'm in the restaurant industry and just a few weeks ago I was talking to our high school aged host about it.
I’ve been working on a six port turbo in my SA. I’ll also admit I really haven’t been following Rob. So imagine my pleasure to see that im running Injector Dynamics, Haltech, DCPower and 10awg for my fuel pump. Sorry, brushless is out of my budget.
Perfect place to go over pump laws: if you want to pump twice the flow, the pump has to spin 4 times as fast and take 8 times the power. They are related exponentially. 3 x flow ~ 9 x rpm ~ 27 x power.
Hi Rob, Castor 927(2 stroke oil) will not seperate in Methanol. I haven't tried in ethanol. Worth a shot, it's cheap and can find it at all dirt bike shops. Also It's worth mentioning that pre mix oil affects fuel calculations as the oil is taking up mass in the injector charge so your actual amount of fuel will be less than if there was no oil mix. It's probably a more pronounced effect in the 2 stroke dirt bike world as some manufacturers recommend 60:1 and some guys run 32:1 or 20:1, so that's way less fuel entering the combustion chamber.
Who is this “Rob Dahm?” I’m old and might have memory loss, but I remember watching videos by a guy named Rob Dahm, who didn’t know much about rotary motors, and was just amazed and full of wonder every single moment! This guy is a rotary motor EXPERT. But I’m glad to still see that joy and wonder! ❤️
Rob, what about a billet steal 10mm thick baffle plate between engine block and the sump? This would produce similar torsional strength (resisting the block twisting) without scalloping out metal material around the dowels
That's actually a very good question, I'm guessing that torsional induced stress is one thing, but I would also think that local deformation (especially on the combustion side) might need more local reinforcement. It would still be interesting to make an FEA if a detailed enough CAD model floats around to do a simulation including internal pressure from the combustion. I don't believe it would permit as much torque as the doweling solution, it might offer an alternative for something in between stock and doweled that is much easier/cheaper to implement without pulling the engine apart.
The doweling prevents the aluminum housing from expanding near the spark plugs under high load. not so much the torsion but the expansion outward. the baffle plate or intake flange and exhaust flanges all help with torsion but sadly the housings flex on the opposite side. You can take a flat stone when tearing apart a motor and see that area bow even on the dowels when you detonate etc
@@FG-418 100% man. Everything you said there makes sense to me. The fact that we are currently using thicker or stronger through bolts/studs holding the pancakes together in compression, the tolerances and differences in materials (alloy rotar housings and cast iron end plates in an alternating sequence and differences in thickness etc) by thickening this studs to make them stronger we simultaneously make material the studs go through weaker? This is exacerbated by the increases diameter of the studs now creates more torque adjacent to the rotation of torque of the spinning motor more chance of binding leading to fracture at high RPM (in my opinion - due material differences - alloy compresses more than iron) I have suggested steel plate in this post, but I personally have chosen to go with an 12mm billit alloy for my motor. I just think the effect would be better using billet steel. Also I believe that the effect would be like what we see in laying carbon Kevlar at alternating layers being laid perpendicular to each order enhancing strength? What about if as I suggested and billet steel baffle plate and then upgrading the sump bolts (longer and higher carbon steel) and then really loading the torque up on those bolts and if needs be drilling out the thickness on the sump standard thread in just the alloy sections of the block and putting in steel nutserts to allow equal torque settings? Currently Mazda doesn't use any of the sump to create additional torsional resistance to the twisting torque of the motor. I actually think that there is more potential to create stiffness or resistance to twisting, this way than by thicker studs as plates just won't be able to physically separate to twist in the first place? On top of that the concept is far less of an issue getting it perfect compared with upgraded or stronger dowels just due to more machining operations across multiple parts. Lower entropy or less chance of fucking it up doing a baffle spacer. This is also stronger than going dry sump as dry in my opinion? Note I'm arbitrarily said 10mm billet steel but it might not even need to be that thick nor billet steel? If it's not sufficient then it's pretty easy to swap out also? 1. Bottom of the block 2. Sandwich steel baffle plate 3. Sump 4. Done
@@RobDahm yes we saw you removing the stuck dowels when you pulled them block apart? I thought about the intake and exhaust flanges contributing resistance o twisti-ness of the block, but I didn't think about the spark plug hole area expansion? That's a whole other kettle of fish that directly affects the timing that you demonstrated in the video we just watched. Which says something about when we see detonated rotars with like fist sized dent in the combustion face 😲 So this is due to combustion temperature, pressure and the material indifference between the steel rotars and "ballooning effect" and outward expansion of the alloy rotar housing? Many rotary engine builders I've spoken to over my time think most of the stresses are due to twisting of the motor? Hence them upgrading to 12A front cover and REW rear mounting and or both? But what you are suggesting is that it's not block twisting per say, but the combination of forces from the difference in materials? So does that mean 12A front mounting has always been a myth?
I dont know enough to comment if its more of one or the other. All of my high power has been done on engines ive doweled and that would prevent much of the twisting. so i dont have an engine where it could have twisted and caused issues at this power level. But even with the dowels i can measure the housings expanding so thats all i can measure and observe. twisting would certainly fuck up a motor, but my issue with twisting is more about how the engine delivers power, it transmits power to the transmission and is braced to the transmission body through the bellhousing. so i think its more about the rear iron constrained to the transmssion that wants to rotate if that makes sense. its not really fighting the engine mount to deliver power. I ran the rotary corvette without engine mounts after the mount broke for 100 miles back from vegas. hanging off the torque tube haha. But on a 3 rotor or 2 rotor with tons of torque im sure twisting is something that could happen. I just dont have enough experience with that type of failure to speak on it.
Wow you guys love this dude. You’ll probably hate on me for this. “Were stopping everything to work on the 12 rotor…”. I just want to see and hear it run ok!
fantiastic video, thanks Rob. Sorry I am in Aus and use proper measuring system 🤣. Did I understand correctly that 1.5 oz per gallon was ideal premix for e85? If I convert that to ratio that's 1:85. That is a lot richer than what my local tuner and rotary builder recommended, they state 1:250 is ideal. I know that conversion math is right but are you certain 1:85 is the ideal ratio?
I dont know the answer to how little to put in, but i can definitely say more than that is too much. I keep reducing the amount i use. But so many people swear by the 2oz to gallon and its just not necessary
@@RobDahm yea ok, cheers thanks mate. The local guy swears even leaner then. 1:250 is 0.512 oz per gallon. This is e85 pump and Penrite 10 TENTHS RACE CASTOR OIL 20W-40. Be interested to hear how you go if you try that. I have run for years 0 issue as has the shop which races and competes
Rob always talks about details of what works and what not. I'm confident now that I could rebuild a rotary engine at home. In the living room. On the couch. ......... Wait, I don't even own a car... 😁😎🤟
@ rod dahm what about clearancing the rotors?? I had a engine apart that the rotors had visually hit the iron in the exact place that people clearance. Aka right below corner seals? So yes clearance or no ? Was my engine just improperly balanced???
stock clearancing should be checked when building them. But tip clearancing is definitely a must for high rpm. just left that stuff out for everyone with a street car build. it makes such wild power across a wide power band and isnt massively ported so you dont have to go high rpm to make the power
@@RobDahm gosh dahm I feel special 😊 yes i was talking about side clearance. My issue could have been from under oiling also. I was running stock ECU with 8k rev limit. I have 2 tenth AE rx7 one is 100% stock the other im building to be fast I'm going to take the tips I learned from this video and apply them!
Can youtube at button to like a video even more than once. Rob has talked about sharing knowledge for years and years and has. But I don't think he's ever gone this far and been like this is my map, Go make happiness. Makes me want a another Rotary so much more. One of these days!!!!!!!!!!
Loved this video and its definitely saved. Two questions though: 1. Why are the primary and secondary injectors different sizes if you set the bigger ones to flow the same as the smaller ones anyway? 2. Does the turblown stud kit also take care of the spark plug area or do you need to get some dowels for that too
So the primary runners are slightly smaller than the secondary runners so at full tilt the larger runners carry more air. I have them both on the same amount of time basically im mimicking the air flow. The primaries technically flow 40 percent of the fuel 1700cc / (1700+2600) and that seems close to the runner ratio. I would personally still dowel the block going over 500 hp often. Or just do the stud kit and pineapple dowels under that. Long ago when first tuning I took a stock block to 600hp and popped it. Took out almost the whole engine and turbo. That was more of a tuning issue than a doweling one but that’s the reality of stock seals and block as a beginner tuner
I'd love to see some rx8 or just renesis content. You seem to have the REW stuff down to a science. I'd love to see your take on their engineering that sort of "ruined" the rotary. Also the chassis is awesome.
8:28 get your CFD on Rob, I bet the bottom of that tank is getting very little flow so 1) its reducing theaverage flow for its given size, and 2) as more flow is proportionately higher up they get more sautrated reducing efficiency. I'm happy to be wrong, I know you know what you're doing... but *I* haven't seen it modeled and while the cross-tubes are a consistent volume (width/depth/height) it doesn't make sense to potentially be limited flow. Again *if* the CFD proves me wrong that's awesome but would love to see it.
Hi Rob do you side clearance the rotor? Do you take 0.005 off each side or 0.0025 off of both sides? When you clearance the rotor do you need to modify the side seals? Do you machine all the way to the centre or stop at the outer oil seal?
I am assuming that the rest of the car won't do 700hp on the wheels without mods. Can you do a no BS video on clutch, gearbox, driveshaft, diff and axles to accompany this?
The rotary has the best torque curve for cornering your race tires won't pop v8 and about pops racing tires while accelerating out of corners during position battles with rotary bank on smooth acceleration and maintain momentum the 3 and 5 mph speed difference through corner adds up if you're consistent your track car pulls away 👍
A few other wild facts here; 3" exhaust, with both wastegates re-routed back in, restrictive Apexi N1 catback( snorkels down to 2.25" tubing at the twin catback), intercooler isn't that big & its tube and fin, intercooler piping is ovaled down 2.5". Would love to see those get changed, but Rob needs to focus on the 12 rotor and pikes peak.
@buildaboiworkshopit’s the minimum and at 700hp and 30psi it’s a huge restriction.
Rob got too many sidequests for his 12 rotor project and Pikes Peak main quest lol
@@rickcupola6262I'm going to start describing ADHD as having too many side quests. 😂
no backpressure sensor? would love to see this again with a 3.5" vibrant oval exhaust.
Is this a 12 rotor? I can't tell anymore.
I'm not a rotary guy or mechanic. I tinker on NA 4 bangers. But i never miss a video of Robs. The only Utuber that explains engines, cncing, wiring, suspension setups, welding. Well everything to a understandable degree. Clear, concise. He just make u think out of the box and reasons for the way things work. Hats off bro.
Rob is awesome, but there are many other youtubers that explain stuff in such a way that even a moron like me can understand it. Al from The Skid Factory, Rich from Deboss and Nik & Richard from Bad Obsession Motorsport come to mind. edit: and if you think that the 4 rotor has been long in the making, then check out Project Binky.
@@pirkkaruuska5766 i watch skid factory, great also for turbos and alike. been a while since i watch binky and the boys at Bad Obs...all great, but Rob is soothing..lol
rob and superfastmatt are the only youtubers whos videos i will never skip, no matter the content
@@carterbliss484 Imagine telling the public that.
Dahm gave me the interest and knowledge to start digging into my cars wiring system and making life easier.
Dudes will see a Rob Dahm upload and go "Hell Yeah"
Hell Yeah
Thats true, i did
Hell yeah
Hell yeah brother
I said Meow
Shout out to the J man for the editing on this video, bouncing around from different shoots to get all of robs wild details in a smooth chronological explanation is no small feat ❤
I work in tech, and the entire time you're talking about the Trigger, my brain kept hearing "It was DNS... it's always DNS."
Really loved the breakdown of fuel/air moving through the engine. I don't tune engines or anything, it was just awesome seeing it explained that way.
My favourite IT-related haiku:
It's not DNS
There's no way it's DNS
It was DNS
There are only a couple TH-camrs that I’m excited every single time they upload. Rob is by far the most exciting even when it’s something small. You keep my dream alive while not being able to complete it myself due to life. Thank you Rob for everything you do for us! We appreciate it all!
No one asked you, allahu akbary ma boy
The only other automotive TH-camr/builder/racer that explains this kind of stuff in such a detailed and bottom line way aside from Rob, in my opinion, is Steve Morris. I’m pretty sure many people would agree in saying that Rob Dahm is the Steve Morris of rotary engines.
I came here to say the same thing. Both legends for the amount of no BS tech info they give out.
Gale Banks shares some good stuff as well
Not by a long shot! I love Rob's stuff, his videos, his builds ect. but come on. One is like the ultimate unlimited budget ADHD hobby man who's doing amazing things. The other is an all time legend who's won so many championships its hard to keep track of, and creates engines from scratch that go out and win countless local events. When Rob starts sell us his own design, all billet rotaries then maybe he'll be like 1/8th of Steve Morris. I'm not hating at all, just looking at the facts.
@@bennyb.1742 Don’t get me wrong, I fully agree with you. Im not trying to take away from Steve Morris or hold Rob Dahm up like he is a god or anything but when you look at both of them on the ground floor, their are quite similar. Steve Morris has poured his entire being into learning everything he can, building an absolute empire from nothing, testing his engines and parts relentlessly to find the weak point, then making revision after revision to produce a rock solid product that he is proud to put his name on and stand behind 100%. All while never trying to bs you, show you the raw data and explain absolutely everything. Yes Steve Morris is at the top level that not many people will ever get close to. Rob holds the exact same core values that Steve does. Rob lets his data do the talking the same as Steve. Rob is on the ground floor of building his empire. They both started from pretty much nothing with a passion for automotive and they are chasing their dreams never giving up and never trying to bs anyone. They let the data do the talking. I apologize for this being so long winded, I wanted to explain in more detail why I see them as being fundamentally equals when you remove all the awards and fame, (that have been rightfully earned) and see them as dedicated mad scientists with a burning passion.
@@Kodaoda You are absolutely correct and I can’t believe I left out Sir Gale Banks.
The only thing that you guys are missing in your RX7 arsenal is an FB RX7… would be real cool to see what Rob could do with a 12A engine
I agree 100%
I think that would be the fun rally car for sure!
I want to see a Cosmo build.
Love to see an RX3... or the RX5 on the hoist in one of the recent episodes.
@@RobDahm Yes.
I'm someone that have been following Rob since 2020, I initially looked at him a bit as "lets see how far this fool will get", like this guy knows nothing but in a friendly way.
Today, I wanna say that this video has been the best one Rob has ever released, very informative, very clear, very knowledgeable.
I can say today that I'm impressed and in a way "proud" of Rob progress in his Dorito career.
Thank you Rob for sharing your knowledge and learnt lessons with the community.
anyone else love getting the notification when rob posts a video just makes me so happy
always, it means it's going to be a great day
Blessings Rob bro, i have an s4 block since 2022 dyno test with 605whp, almost used daily, p/s, a/c. Completely stock s4 intake manifold and throttle, it cruise like stock and handles 25psi with snow meth kit. My 605whp went al 6,480 rpm. And 496lbs torque. Stock heavy flywheel, 1050 inyector dynamic primaries, 2200 original bosch secondarys, microtech lt10c management, precision turbo 7675 with .96 a/r. And this is a small part of the ingredients. Thanks Rob!! Blessings bro! Rotary for life. Puerto Rico 🇵🇷 love rotarys.
Wow that's awesome bro! Any stud or dowels? I'm building a fast 13b now I have a old micro tec lt7 ECU lol. Did you tune it?
Rob Dahm. Your video just helped me solve the issue i v been chasing for 3 years.
I solute you. You are the true absolute Kim Jung Eun of rotary.
31:27 - "There are a billion other details...." Me: Okay Rob, I'm ready to hear them all. Please and thank you!
I’m a 4g63 (Evo) and now a ( 740hp) 4.7 TT Mercedes guy. Been at it for 25 years. I’ve watched your videos for years now and love how humble you stay and yet how knowledgeable you continue to become and grow. You’re the only YT’r that I feel like is a completely relatable person and one I keep cumming back to (har har har)
Keep at it Rob .
Evo to a merc? What a downgrade
Probably more expensive to up keep for sure. But those slk 500 our sick ASF
This video is so helpful for an FC S4 owner. I watch all of Rob's videos but pay special attention the these ones. This gives me hope that I can make my FC an absolute rocket when it get a restoration/rebirth ❤ your work and keep it up.
Check out the Motul Micro oil for premixing, it’s made for R/C nitro engines and may be suitable for your needs. Also yes, decent/oversized even, wiring is always needed for fuel pumps, overlooked many times. Going from the supplied tefzel to 6mm copper cable for that 525 Walbro pump let us remove 10% fuel over the whole map, sounded higher pitched when running etc.
The best additive is paychecks. All of them. They're VERY combustible in rotary engines.
@@ArKritz84 same goes for any car.
@@ArKritz84 🤣 very true
Out of all the TH-camrs with a dyno I really feel Rob would produce some Dahm good content.
Finally someone who’s willing to share tuning knowledge!! ❤
The production quality on each of these videos is insane considering it’s just another TH-cam video. Definitely setting the standard for quality when it comes to automotive videos👏🏼
I cant wait to watch this 12 times. shout out the ultimate wiring guide
Would consider doing a live stream of a tuning session and kinda just show the process of tuning the car? It would be really informative, especially if you built the whole map from the start. I’ve never seen anyone really do that besides hp academy if you buy it.
If you want to do this from the first stages, it would take many many many hours, probably days doing it in a livestream. You have to dot all your i's and cross your t's before you can do the next step. While you are doing this as fast as you can, you spend many hours checking "mundane things" swapping parts, calculating and such. This is all the ground work required that is required to finally have a good "tuning session" on the dyno. Ask any dyno shop; most people that aren't experienced that show up, get sent home to re-do their prep work without getting much performance to show for it during the session. Just showing the dyno bit without showing everything required to make it successful will be not be an accurate depiction of "the process of tuning the car". Having said all this, doing a series on the road to the dyno session and closing it off with that session would be super awesome.
The one rotor has to happen lol. No boost and boost. Let's see what you can rip from one rotor !
350hp lol.
Gotta use a go kart frame for this one
Atkins sells them.
Does a 1 rotor engine even exist, or would that require custom hardware?
Rob, I love all of the insane builds from the 3, 4, and 12 rotor but this FC is by far my favorite car of yours. It’s my favorite generation of rx7 and your work on it has been amazing to watch.
6 seconds, that's the fastest I've clicked on a rob video ever
Should spend some time practicing Grammar.
Oh, and I clicked it in 3 seconds so...
Rob I'm at 699 hp but I'm just missing that little bit. What kind of socks do you wear while on the dyno? This will make or break my 700hp journey
I don't know where this shoot sits in the pikes peak run timeline but I really appreciate the explainers you do. Goated not just for rotaries but as a car channel in general.
Sir, super impressed at where your heads at now compared to a few years ago. Learning about how stuff works and learning why it works are not the same thing. This approach on showing why your results are what they are is probably going to net you some real die hard followers. Hopefully they too will also take the time to learn how and why things work the way they do and gets rid of people copying and pasting everyone else's hard work. Glad you have the platform to say this is what the deal is... keep on keeping on🤙
I appreciate the tidbit about the short pulsewidth adder, showing the table. The file I downloaded from ID has percentages, but the table was wanting ms. I initially ignored the "adder" language and thought it wanted the full value to use instead (which is my interpretation of their kb article defining "effective pulse width") but I found that I only needed to take one step to input the additional amount rather than the total.
I don't even have a rotary, but just having the screen shown allowed me to do a sanity check.
Why am I taking notes right now? I don't even own a rotary, but Rob makes all this info seem too important to not know lol
He is so good at selling you information, and since is for free you just keep wanting more and more...
I don't even have a rotary, but it helps you shape your way of thinking and conside things that you could have missed, he is trully a good teacher.
Taking notes for no reason? What that says is, you have nothing in YOUR actual life that you care about as much as you care about a stranger's actual life.
@@eriklarson9137 good god dude
My first car was a 1987 RX7 base model. The apex seals blew and that was the end of the motor. Sadly, no mechanic in the area would touch that car. Being 18 or 19 at the time, I couldn't afford to keep it until I found someone to fix it. I cried when the tow truck came to pick the car up.
I'm almost 37 and I still have a massive love for rotaries. I do hope they make a comback one day. I doubt it since the EPA is so strict now. The RX-8 was a good example of what could have been, but sadly those had a lot of premature engine failures.
I'm getting ready to have my FD tuned and this was extremely helpful.
👍👍First time I've ever heard a tuner mention running softer ignition settings on lower compression engines, especially on E85. All the 90's-2000's turbo JDM cars were low compression and a lot of tuners tend to lean on that ignition curve because its not pinging. But its not making any more power either. But in a piston engine, it does tend to lift the head instead of making power, and yes keep all that heat in the engine.
I have used DC power alternators before and always been very happy with the results. They look great, they do great power, and they're DEAD RELIABLE.
17:37 Sounds just like someone ranting on SR and RBs, the stock optical Nissan CAS is such a nightmare, causing tons of uncessary and "random" hard to diagnose issues. A good crank trigger just makes the engine feels smooth, solid and responsive. Definitely going to make a custom crank trigger setup for my 13BT2 for my new FB build as well.
I had asked about the injector timing on a previous video, so getting that discussion was awesome, but the timing and lambda tables you use opened up my eyes as well.
My 1987 Non-turbo FC is about to cross 100,000 original miles (car sat for 14 years, thanks USAF)
I had been running it at 23 degrees across the board, compared to your 17 out of boost, as well as your discussion about how timing in cruse is not that important, am going to have to take a look at it.
I've been able to get 32 mpg on flat terrain, but the moment hills start getting involved, I see it drop to around 26.
I do not have easy access to a dyno, so had been turning my timing by setting my AFR to 13 across the board, doing several trips while maintaining speed limit at all times. Change entire map 1 degree, record GPS data, and seeing that areas I needed less throttle (car has been converted to a 100% mustang TPS sensor) I figure that using less throttle, means that you are making more power at the flat and hill locations and have been tuning from that kind of data.
With your previous video showing how off the front and rear rotors were AFR wise, it also made me wonder about an issue I was getting on overrun where the single O2 sensor I have was jumping up and down, but only in overrun, might be that I am getting stream AFR variations on front and rear as well.
I just sent my other car (97 Turbo Miata) engine block in to get it machined, so once I get up and running again, can start ripping into my RX7 and create a turbo system for it.
I like that method to find power without a dyno. I think that running E85 helps him get away with aggressive numbers for both timing and lambda.
sadly i dont recall the video but Rob once spoke about fuel and that it has to be either E85 or E100, other fuels have either too high octane or are too junk and cause the rotors to get covered in carbon/dirty. If you watch his other videos youll notice that his rotor faces are even almost shiny looking, like new.
I just had an idea for getting to the bottom of the oem vs aftermarket manifold.
We have full power comparisons. Great.
Now for the low throttle percentage torque measurements.
Process:
On the oem plenum Figure out what TPS% the secondary throttle start to open. Let say 20%tps- to avoid the secondaries intruding we should aim for 17%TPS.
Now dyno the torque in 3rd gear at 17%tps. For both plenums.
I want to see the difference from the higher velocity on just primaries.
Not gonna lie, I've got a lil' old stick Protege that I've been very slowly restoring, but Dahm's got me to the point of seriously considering rotary-swapping my Mazda, maybe in the next few years...
Love the Rob tuning school. I learned on a power fc and switched to an elite 1500. It's an information overload. Would love to see more videos on tuning tips
I agree more tuning videos is a must
The opening seconds was an absolute BANGER‼️
3:20 you can do the dowel upgrade, but you need guts and a specific tool and patience. You need an expandable reamer (that has the right beach to work on, cause they're not infinitely expanding) and you need some method to make sure you're going in straight. I have, in the past, introduced these reamers in existing holes, un-expanded, and then expanded them slowly, taking just hair shavings off, but you need an even more specific reamer, the gun barrel expandable reamer, which is not only long, but also very accurate across its length. With a regular expandable reamer, you have to use a drill press (a good one) so you can keep going in and out, and average out the losses.
edit: oh and you need lots of oil and a good tap wrench. I'm not kidding with the oil. You have to bathe that reamer in it.
Using stock dowls is cool . Lucky my parents have a milling machine I'm going to try and dowl my next engine
@@jo-qp7mz Be sure to secure the piece down as square as possible. And good luck!!!
Finally someone is actually measuring the air pressures and temps on both sides of the intercooler.
Now you mentioned another key item, and that the heat of the exhaust is power.
Ok then increase your power two ways at one time, and hows that.
Simple wrapping the entire exhaust going to the turbo, and wherever the exhaust is still inside the engine compartment.
This does two things, one it does in fact increase the speed of the tubo by suppling more powerful exhaust pressure due to increasing the hot exhaust blasting the turbo thus spinning the compressor wheel faster creating more boost.
Secondly, by reducing the temperature inside the engine compartment, and this does two things in itself.
Reduces engine soaking as much heat from the heat radiating from the exposed exhaust and the hot side of the turbo that needs a blanket same as exhaust needs wrapping.
Which it lowers engine compartment temperature then you reduce heat transfer to the cold intake pipes, and the manifold itself.
So why not wrap the cold side too, and help it even more.
Win win situation all the way around.
Another thought try to make entering and leaving your intercooler dead center, and by doing so, you increase the air flow through it, and reduce the static pressure caused by the restriction caused by frocing air through just a portion of the intercooler.
Where as if the intercooler is designed correctly then there's a even flow of air across the entire tube sheet, and the air is allowed to loose more heat to the cooler air moving across the outside of the tube sheet fins
The rotary community needs to support this man and his videos more. Thanks for sharing this info with us Rob.
Ive always wondered how tuning a rotary works. Rob reveals so much valuable information in this video! Thanks!
Fuel pumps also work in a way that people don't realize. I have a 7.2 liter that gets around 10mpg...until you drop the pedal to the floor then the pump goes in to truly massive work mode. Do not cheap out or underestimate your fuel demands.
Totally agree with what you are saying and that why I try to get the ambient air into the intake and not air that has passes through the intercooler and or radiator. Also I wanted to know if there was any testing of premix fuel with regard to autoignition temperature.
Love your work and the detail that you show us novices. Thank you and your team, keep up the good work.
I've loved the Wankel from the first gen RX-3. It's the "snarl" of the exhaust notes, although I have to say I love the sound of an aggressive cam in a big block V-8 as well! If I had the $$ I'd put a 13B (maybe a 20B) into a jet boat, one of the short keeled river runners that usually run a Rotax rather than a sprint racer.
Rob, this is far and away the best video you've done. Very strong explanations on a lot of different subjects.
Bravo.
This is the car content I craved as a child but just wasn't provided. Thanks Rob.
When does side clearancing the rotors become relevant? Figured 700 hp is where you start to worry about the rotors walking and contacting the irons.
*relevant
I’m interested in that myself. I wonder what the (relative) longevity will be with that much torsion.
I also want to know? I had a engine with 300 HP or less and it had rotors that had clearly hit the irons in the exact place that people clearance aka just below the corner seals?? I was told by Rob at pineapple racing to clearance every engine and stud or dowel and Ballance if you can afford it and our racing it??? Idk I'm interested to see what master robs input is????
Side clearencing has nothing to do with hp but more for RPM. Rob is peaking his HP at 7k and letting off at 8.5. If you plan on reving past 8.5k on a regular, then clearancing can help.
On the 3 rotor they arent side clearanced and i can see where they make love to the irons. But i spin that engine up almost to 10k often. like rotaryperfection said if its in the normal power band and under 8700 no worries about it. But high rpm definitely a must
@RobDahm right on guys thanks to you both
Interesting info on Turblown's upper intake manifold. I know this video is 6 months old, but Rob, have you been given the chance to test out Turblown's lower intake manifold to get the full package? They do put alot of research in the products.
20:00 I think this is the first time I've ever seen someone in the automotive mainstream on youtube talk about non-linear pulse width response. Though I don't have a wankel powered car it makes sense that low rpm operation with big injectors will be even worse than with the 4cyls I was dealing with. When I cut my teeth on tuning my first turbo 4cyl with big injectors and found out most people just ignore it and idle at 12:1 or something ridiculous and run super rich through all low rpm transients to avoid surging and idle hunting and such. I had to characterize my injectors myself through trial and error, I couldn't afford ID or FIC and just had siemens deka or deatschwerks junk back then! I maintain that making power is easy. Making power with back to back WOT runs on the dyno are so simple a monkey can do it, but idling well, cold staring well, not stalling at lights, not bogging when the AC kicks on, not being jerky at partial throttle during transients, getting good fuel economy, that's what separates a good tune from a dyno tune.
No other Rotary channel like Yours Rob 🔥
I'm learning to build RX-8.
I will use electric super/turbocharger, it's the real deal running on 48V lithium battery that works like nitrous surge.
What is the safe amount of boost or whp with stock internals?
Should i change the rotor using the RX-7 or i can just use aftermarket seal on RX-8 rotors?
What other thing should i consider for boosting RX-8?
Appreciate you sharing as always. I am planning my 700hp build currently. Glad you confirmed a lot of what you did. I have a lot of questions I send over if you dont mind. OMP removed? Only pump e85 and no AI? Did you have 4x 2600cc or just 2 secondaries? Looks like a street car. Did you run into any limits with R3 outputs-fuel pumps, fans, etc? I will have to go back and look at your fuel pump setup. I was planning on 2 hellcats, but i see you called that out directly. Lol
OMP removed. i would do omp pulling from a reservoir as an alternative but all my cars premix. 21700s and 2 2600s total on the entire car. R3 isnt for running lights etc so you have the 4 25 amp outputs and a couple half bridge outputs for drive by wire or electric wastegates. I loved the hellcat pumps but they suck down the power massively.
@@RobDahm So are you just using a TI BKS1001 pump with the external controller only? And are you using -8AN or -10AN fuel lines?
if you don't clearence and balance your rotors, how can you be sure it doesn't make contact with the sideplates at 9-10k. i thought it was a well known problem when making power at those rpms that the rotors wobble and if not clearenced can lead to major damage. if that is caused by something else could you explain by what if you know and why it might be worse to clearence and balance them. thanks in advance.
Hey man, long time no comment. Gotta love the "Keeps" hair continuity shots in this video. That majestic mane of hair is truly alive 😻 🚗 💨
This is a great video, lots of technical info. 0.81 Lambda at 20psi boost sounds aggressive for a turbo rotary IMHO, I'm guessing this was on E85 and not pump fuel?
Pump E85 according to Rob’s comments on Facebook
The world needs more people like Rob, who want to share their knowledge so everyone can enjoy things.
I use lucus 2 stroke motor oil at 2oz per gallon and have no problem with smoking and the inside of the motor was super clean when I rebuilt it due to a oil pressure spike
Dyno numbers can be manipulated to anything you want. Show us some performance from any of these cars to back up the dyno numbers
The king of youtube rotary corn has posted lets go 🔥💪
Wow man what a video, Im blown away on your info, editing and content of said info. I will definitely save this for the future when I do this one day keep going man if you keep going in thid direction like you did with this video you will be huge but that's not the point! Everybody deserves to learn this info about tuning so everybody could be better❤❤❤❤❤❤❤❤❤❤❤❤🎉
Rob has earned his title of Rotary God through pure effort
Watching this video really makes me want to build something with a 13b now lol
Hey Rob, when are you going to build a big power supercharged rotary? I've always been curious about what the limits are as far as supercharger size(and resulting parasitic drag) vs engine size. Would be pretty interesting to see what a 13b does with like a 3.0l Whipple twin screw or a Vortech YSi centrifugal attached to the crank.
Thanks for always dropping great videos, it’s motivating 🤙🏼
(trying to get my turboII on the road this summer)
I can put this video on my preteen niece's random playlist & it will still be easy and enjoyable edu-creation walkthrough, prop's to the legend himself!
Thankyou for all the info Rob, pls make another video regarding closed loop and boost tuning.
This feels like college again.. love all the information. Definitely gonna be rewatching this like 12 times. I have the turbo, 4 port manifolds, fuel system, intercooler system, and Haltech 1500 for my 1988 GTU (6 Port NA.) Is there any opinion on the IGN-1A coils vs LS Coils in terms of cost/performance/availability. The biggest hurdle for me is it's a perfectly running 70k mile 13B, trying to be the least intrusive to the keg itself. I honestly just want to make 300hp!
Excellent tech vid. I configured the short pulse width adder data for my ID injectors, but the part that throws me off is that the right most value in the ID provided data is not 0. So does that mean its carrying out that last value across all greater pulse widths? If so, doesn't that just mean you should adjust the injector flow capability chart? 19:45
Rob, this is your best vid yet.
What are you doing to keep the "fireballs" on decel to a minimum?
Also, Awsome video, you broke down some pretty complex ideas fairly simply and showed the numbers! Bravo!
I set my decel fuel to slightly rich to cool the combustion chamber but not so rich it collects. i think its at .72 lambda roughly
That's what you want to see from an intake upgrade on any engine. More power at the same boost but more importantly less boost when you max out the turbo. The important thing to take away from that is a turbo isn't limited by boost it's limited by airflow. When the same amount of airflow has less resistance you make less boost. Too many people ask "how much boost?" without understanding what it really entails. A stock 5.3 ls at 25 lbs of boost is gonna make a lot less power than the same 5.3 with nice heads/cam/intake/turbo system etc. with the same displacement.
You'll enjoy watching robs last video (I think..) he's definitely said exactly that in one of the recent ones. Almost verbatim 😅 thought you were quoting. Enjoy the validation!
@@blitzroute66 lol he did didn't he? I legitimately forgot about that. It's just something I find myself explaining a lot. I'm in the restaurant industry and just a few weeks ago I was talking to our high school aged host about it.
I’ve been working on a six port turbo in my SA. I’ll also admit I really haven’t been following Rob. So imagine my pleasure to see that im running Injector Dynamics, Haltech, DCPower and 10awg for my fuel pump. Sorry, brushless is out of my budget.
Perfect place to go over pump laws: if you want to pump twice the flow, the pump has to spin 4 times as fast and take 8 times the power. They are related exponentially. 3 x flow ~ 9 x rpm ~ 27 x power.
Hi Rob, Castor 927(2 stroke oil) will not seperate in Methanol. I haven't tried in ethanol. Worth a shot, it's cheap and can find it at all dirt bike shops.
Also It's worth mentioning that pre mix oil affects fuel calculations as the oil is taking up mass in the injector charge so your actual amount of fuel will be less than if there was no oil mix. It's probably a more pronounced effect in the 2 stroke dirt bike world as some manufacturers recommend 60:1 and some guys run 32:1 or 20:1, so that's way less fuel entering the combustion chamber.
32:1 or 20:1 is more fuel going in. 60:1 is 60parts of oil per million parts of gas. Compared to 20parts oil per million parts of gas. FYI 👍
Rob educating the kids. Keep up the good work. Love the vids. Can't wait to see rip some of these.
Who is this “Rob Dahm?” I’m old and might have memory loss, but I remember watching videos by a guy named Rob Dahm, who didn’t know much about rotary motors, and was just amazed and full of wonder every single moment!
This guy is a rotary motor EXPERT.
But I’m glad to still see that joy and wonder! ❤️
Amazing how you’ve made it 39 years with hair but this product magically saved it 🤯
Rob, what about a billet steal 10mm thick baffle plate between engine block and the sump? This would produce similar torsional strength (resisting the block twisting) without scalloping out metal material around the dowels
That's actually a very good question, I'm guessing that torsional induced stress is one thing, but I would also think that local deformation (especially on the combustion side) might need more local reinforcement. It would still be interesting to make an FEA if a detailed enough CAD model floats around to do a simulation including internal pressure from the combustion.
I don't believe it would permit as much torque as the doweling solution, it might offer an alternative for something in between stock and doweled that is much easier/cheaper to implement without pulling the engine apart.
The doweling prevents the aluminum housing from expanding near the spark plugs under high load. not so much the torsion but the expansion outward. the baffle plate or intake flange and exhaust flanges all help with torsion but sadly the housings flex on the opposite side. You can take a flat stone when tearing apart a motor and see that area bow even on the dowels when you detonate etc
@@FG-418 100% man. Everything you said there makes sense to me. The fact that we are currently using thicker or stronger through bolts/studs holding the pancakes together in compression, the tolerances and differences in materials (alloy rotar housings and cast iron end plates in an alternating sequence and differences in thickness etc) by thickening this studs to make them stronger we simultaneously make material the studs go through weaker?
This is exacerbated by the increases diameter of the studs now creates more torque adjacent to the rotation of torque of the spinning motor more chance of binding leading to fracture at high RPM (in my opinion - due material differences - alloy compresses more than iron)
I have suggested steel plate in this post, but I personally have chosen to go with an 12mm billit alloy for my motor. I just think the effect would be better using billet steel. Also I believe that the effect would be like what we see in laying carbon Kevlar at alternating layers being laid perpendicular to each order enhancing strength?
What about if as I suggested and billet steel baffle plate and then upgrading the sump bolts (longer and higher carbon steel) and then really loading the torque up on those bolts and if needs be drilling out the thickness on the sump standard thread in just the alloy sections of the block and putting in steel nutserts to allow equal torque settings?
Currently Mazda doesn't use any of the sump to create additional torsional resistance to the twisting torque of the motor. I actually think that there is more potential to create stiffness or resistance to twisting, this way than by thicker studs as plates just won't be able to physically separate to twist in the first place? On top of that the concept is far less of an issue getting it perfect compared with upgraded or stronger dowels just due to more machining operations across multiple parts. Lower entropy or less chance of fucking it up doing a baffle spacer. This is also stronger than going dry sump as dry in my opinion?
Note I'm arbitrarily said 10mm billet steel but it might not even need to be that thick nor billet steel?
If it's not sufficient then it's pretty easy to swap out also?
1. Bottom of the block
2. Sandwich steel baffle plate
3. Sump
4. Done
@@RobDahm yes we saw you removing the stuck dowels when you pulled them block apart?
I thought about the intake and exhaust flanges contributing resistance o twisti-ness of the block, but I didn't think about the spark plug hole area expansion? That's a whole other kettle of fish that directly affects the timing that you demonstrated in the video we just watched.
Which says something about when we see detonated rotars with like fist sized dent in the combustion face 😲
So this is due to combustion temperature, pressure and the material indifference between the steel rotars and "ballooning effect" and outward expansion of the alloy rotar housing?
Many rotary engine builders I've spoken to over my time think most of the stresses are due to twisting of the motor? Hence them upgrading to 12A front cover and REW rear mounting and or both?
But what you are suggesting is that it's not block twisting per say, but the combination of forces from the difference in materials?
So does that mean 12A front mounting has always been a myth?
I dont know enough to comment if its more of one or the other. All of my high power has been done on engines ive doweled and that would prevent much of the twisting. so i dont have an engine where it could have twisted and caused issues at this power level. But even with the dowels i can measure the housings expanding so thats all i can measure and observe. twisting would certainly fuck up a motor, but my issue with twisting is more about how the engine delivers power, it transmits power to the transmission and is braced to the transmission body through the bellhousing. so i think its more about the rear iron constrained to the transmssion that wants to rotate if that makes sense. its not really fighting the engine mount to deliver power. I ran the rotary corvette without engine mounts after the mount broke for 100 miles back from vegas. hanging off the torque tube haha. But on a 3 rotor or 2 rotor with tons of torque im sure twisting is something that could happen. I just dont have enough experience with that type of failure to speak on it.
Wow you guys love this dude. You’ll probably hate on me for this.
“Were stopping everything to work on the 12 rotor…”.
I just want to see and hear it run ok!
fantiastic video, thanks Rob. Sorry I am in Aus and use proper measuring system 🤣. Did I understand correctly that 1.5 oz per gallon was ideal premix for e85? If I convert that to ratio that's 1:85. That is a lot richer than what my local tuner and rotary builder recommended, they state 1:250 is ideal. I know that conversion math is right but are you certain 1:85 is the ideal ratio?
I dont know the answer to how little to put in, but i can definitely say more than that is too much. I keep reducing the amount i use. But so many people swear by the 2oz to gallon and its just not necessary
@@RobDahm yea ok, cheers thanks mate. The local guy swears even leaner then. 1:250 is 0.512 oz per gallon. This is e85 pump and Penrite 10 TENTHS RACE CASTOR OIL 20W-40. Be interested to hear how you go if you try that. I have run for years 0 issue as has the shop which races and competes
Love this. Was just wanting to build one
I don't own a rotary, but I'll be damned if Ive ever missed a rob video in the last 8 years.
Rob always talks about details of what works and what not. I'm confident now that I could rebuild a rotary engine at home. In the living room. On the couch. ......... Wait, I don't even own a car... 😁😎🤟
@ rod dahm what about clearancing the rotors?? I had a engine apart that the rotors had visually hit the iron in the exact place that people clearance. Aka right below corner seals? So yes clearance or no ? Was my engine just improperly balanced???
stock clearancing should be checked when building them. But tip clearancing is definitely a must for high rpm. just left that stuff out for everyone with a street car build. it makes such wild power across a wide power band and isnt massively ported so you dont have to go high rpm to make the power
@@RobDahm gosh dahm I feel special 😊 yes i was talking about side clearance. My issue could have been from under oiling also. I was running stock ECU with 8k rev limit. I have 2 tenth AE rx7 one is 100% stock the other im building to be fast I'm going to take the tips I learned from this video and apply them!
You should try one of hose 4 barrel fuel injection throttle bodies to see the power difference. A lot of drag cars use them.
My friend did this, OEM intake and bit a bit smaller turbo, 91oct + meth, 540whp, it rips, black marks over 60mph on the highway with big tires.
Can youtube at button to like a video even more than once. Rob has talked about sharing knowledge for years and years and has. But I don't think he's ever gone this far and been like this is my map, Go make happiness. Makes me want a another Rotary so much more. One of these days!!!!!!!!!!
Loved this video and its definitely saved. Two questions though:
1. Why are the primary and secondary injectors different sizes if you set the bigger ones to flow the same as the smaller ones anyway?
2. Does the turblown stud kit also take care of the spark plug area or do you need to get some dowels for that too
So the primary runners are slightly smaller than the secondary runners so at full tilt the larger runners carry more air. I have them both on the same amount of time basically im mimicking the air flow. The primaries technically flow 40 percent of the fuel 1700cc / (1700+2600) and that seems close to the runner ratio.
I would personally still dowel the block going over 500 hp often. Or just do the stud kit and pineapple dowels under that. Long ago when first tuning I took a stock block to 600hp and popped it. Took out almost the whole engine and turbo. That was more of a tuning issue than a doweling one but that’s the reality of stock seals and block as a beginner tuner
I'd love to see some rx8 or just renesis content. You seem to have the REW stuff down to a science. I'd love to see your take on their engineering that sort of "ruined" the rotary. Also the chassis is awesome.
Gotta keep watching rob to keep my hype up for the awd 13b 67 Datsun roadster
Loved this, great stuff!
8:28 get your CFD on Rob, I bet the bottom of that tank is getting very little flow so 1) its reducing theaverage flow for its given size, and 2) as more flow is proportionately higher up they get more sautrated reducing efficiency.
I'm happy to be wrong, I know you know what you're doing... but *I* haven't seen it modeled and while the cross-tubes are a consistent volume (width/depth/height) it doesn't make sense to potentially be limited flow. Again *if* the CFD proves me wrong that's awesome but would love to see it.
It has a internal divider in the inlet endtank.
Rob dahm is gods gift to those who have epitrochoid shaped hearts
Hi Rob do you side clearance the rotor? Do you take 0.005 off each side or 0.0025 off of both sides? When you clearance the rotor do you need to modify the side seals? Do you machine all the way to the centre or stop at the outer oil seal?
The best Ford v8 track setup 9k rpm and 987 hp felt like a Ferrari v12 and shifts like one rpm needle still high in the power band
One thing gale banks pushes is cubic volume of air rather than boost. Cool to see this in effect
Density 👍
Great video, one question with regards to fuel. I am assuming you had to upgrade the factory hard line, correct?
I am assuming that the rest of the car won't do 700hp on the wheels without mods. Can you do a no BS video on clutch, gearbox, driveshaft, diff and axles to accompany this?
The rotary has the best torque curve for cornering your race tires won't pop v8 and about pops racing tires while accelerating out of corners during position battles with rotary bank on smooth acceleration and maintain momentum the 3 and 5 mph speed difference through corner adds up if you're consistent your track car pulls away 👍