I usta think "No replacement for displacement"......right up until I had a built turbo engine. When boost hits, real boost...its like the Millennium Falcon in STAR WARS. Great work as always, Richard !! LS guru
The one thing I want to mention on the concept of a turbo cam- turbo specific cam grinds were much more prevalent 30 years ago when high power turbo engines used less advanced turbo and turbine design which had higher backpressure. If they weren't careful with their cam timing and valve overlap, the increased back pressure would push exhaust back into the cylinder and you'd end up with a really weird curve and dropping power. Even nowadays it's not really a good idea to put a big overlap cam with a small turbo, if for no other reason than just turbo response. Basically, size your cam and turbo so they work with each other and you'll be fine.
Every bit of that is truth! The first time I rode in my buddy's gto (5xx whp nah/7xx procharged) I was no longer an na guy. I thought it was fast before it even go into boost and man did it come ALIVE under boost 🤤. Stock bottom end except for arp hardware throughout and it had one hell of a top end. Changed my entire Outlook
After you have the boost hit at 3000-6600, you’ll swear it’s a ScatPak. The key on older engines is a rising boost curve and a tune. If you are hitting a 50 year old block 600-700 ftlbs at 2000 will break it. You can have your cake and eat it too. 450ft lbs at 1500-2000 fine, hit 3000 and have 600-up to 750 to 6600, that’s cooking. A modern OD trans you will laugh your balls off at the new stuff when an old boomer car stays right with them or better. 😈
@@Bbbbad724 it was an 05 gto 6 speed car and it was in the 9s. It was one nasty car 🤤. I love classic muscle to though and never underestimate what's under someone's hood especially if I see radials or slicks. He sold it and I was furious lol
Lag is present in every turbocharged vehicle I have owned, but I have found that I adjust to it. I can go from my NA LS1 Camaro to my Dodge turbodiesel with no problem. It's just a matter of timing. On a turbocharged vehicle, I push down the accelerator a second sooner to get the torque when I want it. I bought a Pontiac Sunbird turbo new in 1985 and drove it for 14 years. Full boost was achieved on that engine by 2500 rpm. I used to autocross it, and got used to keeping my throttle foot down while left-foot braking in the slow turns if engine speed got below the turbo. Opening the throttle helped keep the turbo up to speed.
Turbo lag was much more of an issue back when turbo motors had low static compression ratios. When there was no boost they were real dogs. Today's boosted engines running higher C/R run pretty good even before the intake charge is pressurized when they are essentailly NA engines with restrictive exhausts (as the turbo does in fact impede exhaust flow).
It's nice to view a video from someone who actually knows something about turbos. I'm really tired of reading & watching videos and hearing the turbos are junk, turbo engines always blow apart, etc. A turbo-equipped engine can be very powerful and last for a long time IF the engine/turbo setup was designed well, and proper maintenance is performed regularly.
Man I have a myth busting combo, stock 280k 4.8 Silverado with a 67/65 .71ar turbo that I built to tow sees 7 psi at 1800 rpm under load and it's been alive for 6 years and 80k miles. Richard is preaching truth 🤙
I believe for turbo lag it is the response of the NA motor that people are missing. Some of this comes down to compression ratio and how good the motor itself is responsive without the turbo. Another is the time it takes the air to fill cylinders at the crack of the throttle opening。 I say build a good N/A but engine and use the turbo as your power added but build smart as you need to check your ring gaps. Also with your power in mind heat management along with tune is also key
#5 Turbo Lag: When high HP engines are built with a big turbo there is a certain rpm where it begins to make big power after the turbo spools up and produces boost. BUT... a high HP N/A engine ALSO needs rpm to make big power as they rarely make power or torque down low. So, although an N/A engine doesn't have "turbo lag" it does sorta have "power lag". Pretty much the same thing.
Internal combustion engines are lag machines yeah but the situation is waaaaaaay worse with a turbo on a race track. Thanks to gears you can always keep the na motor at powerband in a track but with turbo when you let off the gas all the boost is gone and you have to wait again to get that boost regardless of your rpm. No such thing in an na motor
I agree Rich, I want a VS 7875 with iron logs tied together and the air filter at the headlight bucket and the hot exit straight out the side about 18 in of 4 inch. I may have a intercooler I can get. Air/ water with windshield wiper fluid in it for 12 lbs boost. It is a 105 block that bitted 3/16 4.09x 3.98 around 420ci with .170 walls. It should be 750 at the tires. The 394 in the car NA will burn 16x8 60 series until I let up. The neighbors hate that when I do that and get out with my white cane and walk in the house.
I remember how the low compression myth made so many honda guys build REALLY crappy engines with like 8:1 compression. I think the main reason was tuning back in the late 90's and early 2000's was super primitive so the tuning margins were awful. Someone on honda-tech built something like a 14:1 turbo build to disprove the myth and good god did it make power. Per pound of boost the gains it was seeing was INCREDIBLE. I think what ended up happening was the piston pins bent, pistons kissed head, engine went boom. It wasn't due to tuning or compression, was just reaching the limits of the components it was built with.
I’m constantly surprised how much we think alike! I’ve always laughed about that “Turbo Lag” myth!! ,..And also the measurements if BOOST IN POUNDS ,..actually being not what you’re boosting the engine, rather how much it’s NOT USING 😀. It’s comical how many people haven’t realized these two VERY IMPORTANT facts!!
Myth 5 is why I went ecoboost in my new truck over the 5.0. People were saying you had to rev the ecoboost to the moon to pull a trailer, when its actually the opposite. The 5.0 doesnt make even good torque until 4000, and the ecoboost is well beyond the 5.0 max torque as low as 2800. I tow my trailers under 4000rpm on the ecoboost. But my 5.0 Constantly sees redline for the same acceleration.
One your best/most helpful ones yet . I'm back and forth going turbo from a hard charging procharger sbf . Fast efi and all the goodies to twist it up high. That kind of a hard spend these days to change it but you about got me convinced. Til next time bud
Thought that was the point, make the same at 6000rpm as 7500rpm? Feel free to disagree! Batting it round now! But, a shot of gas once in a while seems cheaper, especially since I have a hundred shot here! Maybe I'm not aiming high enough, but how much can your chassis take without up grades! You'll never outrun the dope dealers!
Turbo lag is what happens when you are in boost and lift off and go back in boost What is commonly refered to as "turbo lag" is the boost threshold, which should really be vaccuum threshold because thats when you make full boost.
I'm glad somebody understands..... Rich touched on that idea for a quick second on one of his vids, but never really followed up on the idea. Yes, boost response depending on turbo size on an engine dyno are one thing..... But how they work on the street with a manual transmission are totally different... Even factoring in perfect tuning with your BOV('s)
@@bradywebb1311 true, moving from a stock transmission to an h pattern dogbox reduced lag, then moving to a sequential pretty much made it disappear to the naked eye on the boost gauge.
@@kkmfc3s I mean.... Anything you do to reduce shift time will reduce perceived lag. But, I'm talking about us normal guys that don't want to spend $15K on a transmission. Might as well put an automatic in it and be done... I like a good ole fashioned clutch with some synchros to blow up... 😁
@@bradywebb1311 yes even moving to an automatic will help, it won't unload the motor during shifts. For me it was necessary to meet my power goals and still have the car work on the road course, kill lag and have close ratio's to keep the engine in the powerband. Even the previous 5k h pattern dogbox was massive improvement over stock.
In response to myth #1, I always see a lot of focus on choosing the right turbo by looking at compressor maps. But how do you go about choosing the right turbine size being that theres a lot of turbos that come with the same compressor but different turbines? Are there calculations to figure out the exhaust flow of a given engine combo?
Turbo manufacturers make turbine maps all the time, but they're not easy to interpret for applying to engines. The problem is the pulsed flow that comes from the exhaust port. Pressure pulsations in the turbine housing make the turbine operate at different points on the map depending on what part of the engine cycle is occurring from millisecond to millisecond. In order to calculate a match point for flow on a turbine map, you would need to have dynamic pressure data within the turbine housing, and do a time average of flow for an engine cycle to know where it is operating.
@@andyharman3022 That makes perfect sense. I never though about the pulsing nature of the exhaust. That being said, when choosing a turbine do you just talk to a expert that has previous experience? Or is there a way to at least make an educated guess?
@@THEMADTYPH00N Talk to experts that have experience in turbo matching and be sure of what you want your turbo system to do. I you're running standing-mile or Bonneville, you can accept more lag to get more top-end power by having lower exhaust pressure. If you're doing 1/8th-mile drags you need to get off the line hard and can't accept a lot of lag. And don't just talk to one expert, talk to a few.
@@THEMADTYPH00N yes you can calculate the expected air flow your engine flows and size the turbo accordingly but having said that no graph or chart compares with real world testing and experience as numbers don’t always give the best driving results
As someone who just finished my Single 88mm turbo build on a 10.6:1 496 Big Block Chevy, I can confirm most of these myths are false. Higher compression and boost are great together and I’m at full boost around 3200rpm. With big block torque, the lag doesn’t really exist, you’re already smashed in the seat anyway.
I broke a Pontiac 400 crank in half Front 2 rods and the front half of the crank right out the back of a 77 trans am at the drag strip back in the late 80s that car ran 11.01 . Best aways right there 02 or 03 never that 10.99 . Last night of the season it kept giving the distributor a little . Then a little more . No timing light . Then one more time. She left and was on a mission slammed second at 6800 ish and let her eat to the traps just before the traps at around 7000 she just about took the hood off. It buckled the hood up you could put your arm in over the fender with it still closed . It was dumb but amazing. Back then grab another 400 off the garage floor and be back at the track on Wednesday
I love your philosophy: NA cars have lag 100% of the time. I have never owned a V8 with forced induction, but I have owned an NA LS, supercharged V6's and turbo 4's. I had a wrx with a 71 lb turbo, cams, ported heads, big front mount ic (opposed to top mount that are the norm on subies), and water meth etc. Many of the guys I knew that had wrx/sti were always concerned with turbo lag, yet wanted big power. They wanted tiny hot sides and small top mount intercoolers and then wanted 20+ psi. Basically, crazy backpressure, higher intake and underhood temps and a limited top end. Roll raced like a half dozen other subies set up like this and the result was always the same, they never pulled away on the small end and I gapped them bad on the top end. Turbo lag was never an issue ever.
Hi Richard here is an Idea 💡 not sure it would work but here you go. The thought is take the inside door Condenser and run the hot air across the coils witch will hopefully cool it down hopefully. I'm not even sure it will make sense. But its just an idea 💡.
Richard! I was under the impression that lower center line cams ( say 106 vs 112) do not maximize the turbo efficiency per se. Yes a 106 center line will work but the wider center was a better choice for the turbo
I still find guys on Facebook saying a turbo cam is necessary. What it really stims from is DCR, which falls more in line with your high compression myth. Most "Turbo" cams are the same as their N/A counterparts with a wider lobe separation. Specifically they'll retard the Intake center line to lower the dynamic compression of the motor. Again, increasing your tuning window. This is also why some cams will recommend a compression ratio. Because they know that big cams kill DCR (and therefore torque) so they tell you to run more compression to make up for the fact.
My bone stock vr6 has an hx35 on 9psi of boost with e85 and man does it love life! 10.7ish:1 comp. Also, if I’m doing 80 in 5th gear, about 3500rpm, full boost when I mat it! Car also has an extremely efficient water to air inter cooler and man does it work! Ambient temps can be about 85 degrees and iats are about 90-100.
11:30 I think the myth of turbo lag comes from people confusing boost threshold vs boost lag. Boost threshold is the point at which your engine is able to produce boost, vs lag which is the delay when you're at your boost threshold and you go from an off throttle state, back onto the throttle. A responsive turbo will still not reach peak boost till it hits a certain rpm, but it's off/on boost response will be better than a larger turbo. boost threshold is flooring it at 2k and seeing when the engine finally is able to spool up the turbo and make power.
I want an all aluminum 427 Windsor motor with kasse p38 heads. They are good for 750 horsepower and 600 lb/feet of torque......and no lag. They will also run on pump gas and have hydraulic lifters so valve lash adjustments don't need to be made. Plus, I love the sound of the stroker with a snappy cam profile. Just a thought.
LTG community strongly believes in having forged internals. Nobody really wants to touch the engine without extreme expense, which just makes it less reasonable to competitor options from BMW or Audi. I think, just as you said, it could really benefit from proper ring gap to deal with higher turbo.
Mr. Richard your video was clear and concise, but i still have questions and comments. 1. Would it be logically better to size a turbo according to double the CFM of air an engine could breath? Or am i just complicating things? 2. I agree with the compression ratio comment and in the future I'm gonna build forged bottom ends with the OEM compression ratio. 3. I learned that with turbo engines you want to minimize the valve overlap. A cam made with a reduced overlap compared to an OEM N/A cam is considered a "turbo cam". Is that correct? 4. "Turbo lag" is actually boost threshold per Maximum Boost 💪
DO NOT MINIMIZE OVERLAP-THAT IS A MYTH. DO NOT CHOSE A TURBO BASED ON DOUBLE AIRFLOW OF NA MOTOR-JUST PICK THE TURBO SIZE BASED ON DESIRED OUTPUT (EXAMPLE 700 HP),
Beautiful, absolutely awesome. I can't wait to boost my gen iv 6.0 sierra. I've never seen you do an hx35 turbo on a ls. Maybe more content to come:)? They are cheap and pretty easy to come by. It not a big turbo but it's also not super small. Makes a guy wonder what he may get? Maybe even do a 5 nitrous myths.. ha!
Richard, I agree that any cam is a turbo cam. Also, any cam is a centrifugal supercharger cam. In both cases the device used to provide boost is a compressor. However, a roots style blower is not a compressor. Boost is produced in the cylinder so, I wonder if the timing of the intake valve closing event affects boost. My question is, does the cam matter with a roots blower?
Richard I've been watching for years and was wanting to see something on spark plug gap's and ignitions. What can be gained from MSD over the stock system. Be nice to see it on the Dyno or if you have any I somehow missed it.
I find it interesting these 'myths' that are 'common knowledge' with machine shops around the country, always have no beginning basis, but often are touted as truth, with the speaker of the myth claiming you will destroy yourself (your engine) if you don't listen to them. Same concept with low compression being a necessity for a towing motor. I have been running 11:1 comp in a BBF for years now, with no issues. Yet, every machine shop always told me I would destroy my truck by blowing up the motor and having a major wreck wherever I go if I dared to go further than 9:1... Finally I just quit saying what I was building until after I built it, so I didn't have to take a brow beating...
Thanks for clearing this up.i been saying to myself for the longest. Now I hear you talk about ring gap a lot can you explain what this does and how it's better . maybe I missed the video of this explanation.
Not that I don’t agree , but depending on boost - then overlap ? So have you see , bisimoto’s d16 cam Independently tested and gained 50 hp or so than the next top cam
Moment of Inertia. That is why two small turbos can have less lag than one large one. Smaller diameter compressor and turbine wheels have less resistance to angular acceleration. Moment of Inertia increases with the 4th power of the diameter, so if the wheels of the two 500 hp turbos have 20% smaller diameter than the wheels of the single 1000 hp turbo, they will have 41% of the rotational inertia. But rotational inertia is not the only determinant of how much lag a system will have. Turbine housing throat area also has a lot to do with it, as do cam specs, induction system volume, and exhaust manifold design.
@@richardholdener1727 Energy is the major input to the system that is mostly controlled by the driver's right foot. Mass flow of air and burning fuel increasing the exhaust temperature. Inertia of the turbo wheels absorbs power from the exhaust stream and is resistance for accelerating the turbo. Another factor that twin turbos can have in their favor is the elimination of the crossover pipe that a single turbo would have on a V-type engine. Keeping the pipe runs short reduces heat loss before the turbine.
Hey Richard. Basically we should pick the best NA cam and go with that? I saw your test on overlap/lsa and how that was not a significant factor when going with boost.
I wish you would explain why camshaft manufacturers or regrind companies even make turbo camshafts and the main reason is to stop exhaust reversion. so if you have a crazy high lift cam with a shitload of overlap... you can only run a little bit of boost before you run into reversion. But up until you get to that point the turbo will be super responsive and then you'll hit a wall and if you try to push through the wall you'll blow it up. Maybe I'm wrong but that's how it was explained to me please correct me if I'm wrong.
that is not correct-boost does not flow through to the exhaust (because exhaust has higher pressure than intake) stop worrying about overlap-it is your friend for making power
The turbo Corvairs ran 6.5 to 1 for compression ratio. These are cars from the '69s and they worked just fine. In fact, they had more torque, especially in the low rpms. Weird but they were the best torque producers out of those air-cooled motors.
Is a remote turbo like we were talking about earlier equal to under hood ones. I was thinking of a 950 hp turbo in front of the rear wheel with my headers and a crossover behind the headers the pipe going back to feed the turbo a 2.5 and runs a pipe to the front intercooler right at the front tq box and up to the bonnet. I have been thinking about it the two ways, will a 7875 VS work for either?
How much cooling can an air only inter cooler provide? How much cooling can a rich fuel mixture provide? Degrees in Degrees out at one bar? Great video
Higher compression means better fuel. Richard doesn't find many benefits to using methanol injection (everyone else does) but this is when that would be a great addition
Hi, great info, really appreciate it. I'm trying to figure out the best setup for a marinized 454 that I have running a jet unit in a boat. I found some old gale banks water cooled exhaust manifolds here in New Zealand, which was rare...so I need to figure out the best twin turbo setup....the jet unit can't go past 3500 rpm so I need max power/torque at around 2700-3000rpm which I know is a big ask....any recommendations for which turbos to use? Thanks
I'm confused, Dr. Holdener - please help... Twin GT35 setup/LQ4 6.0... E85 is not readily available where I live - Detonation is a real concern for me. Should I run my 317 heads, bc they offer lower compression? I have a set of 826 heads which will provide more power but... 500 wheel, street fun is all I care about - not max effort.
People lost their minds when I decided to run my stock bottom end lq4 with ls3 top end and a "stage 4" summit cam to 7500rpm. Nobody had any reason as to why I COULDN'T. Its fine. Done a ton of passes (N/A). Can't wait to get my GT45 on this beast, as Holdner said about the N/A combo, trap speeds equate to around 500hp at the crank... For a motor build that cost $1500cdn lol Trying to get into the 8's with a 4th gen firebird, will be following Holdner's advice the entire way :)
Test the 4.7 that came in jeep dodge and Mitsubishi....... They are just like the 4.6 Ford..... The initial run of the 4.7 engines started with only 235 horsepower the last 4.7 produced 335 hp manufacturer increased horsepower drastically over the years.
Hi Richard, so according to your video I can build my twin turbo Jaguar V12 engine with the stock 11.5 CR pistons? This should be expensively interesting! Shall I give it a go? Or do you advise going for lower CR with custom pistons? Stock rods and the stock steel cranks are unbreakable in these engines so I'll leave them be. What are your thoughts?
What about the older buick grand national turbo engines? They had a stock CR of 8.1:1 and detonation was/is still a big obstacle for them to overcome without adding alky, or e85. Can you dive more into the turbocharged engines from 80's buicks? Any up to date solutions to running a higher CR, and not worrying about detonation? Maybe e85 is the solution?
Hey Rich, recently came across your channel and am enjoying all your fact based educational content! If you ever see one in the junk yard, I'd love to see you do a Big Bang on the Toyota/Lexus 1UZ. I know there's not much after market for it, and the stock cams don't offer much top end, but I'd still like to see what they can take/make on max boost!
On a 5.3 truck motor do you absolutely have to ring gap if you're only looking to turbo it up to around 650hp? Or is ring gap only absolutely needed if you're looking at super high hp?
If you were to build a boosted motor combination that would come into boost at 2500RPM, lets say a 4.8 what turbo would you use? Would it still be the classic GT45 maybe with some high compression pistons, long headers and a neat cam ?
I have a question about LSA in a cam and it's effect on boost response. Reason being is I remember reading an article where Kenny Duttweiler (I believe) was saying his ideal turbo cam had a tight LSA and a reverse split duration, but all cam companies' off the shelf "turbo" grinds are usually single pattern with a wide LSA. So who is right?
I don't think it is so much a question of can you make a specific cam that works better with a turbo, as much as it is a question of will all cams work with a turbo. You could ask the same question about can you make a better cam to work with N/A CNC ported Brodix heads than the stock heads? Everything can be tweaked and tailored to get that little bit more out of it. The question you have to ask yourself is it worth all the R&D time and money over what is already available?
What about my 245 on both sides @.050 and.600 lift on a 110 hydraulic roller cam? I have a 428 iron crank and forged stock 5140 forged rods with ARP bolts.
@@richardholdener1727 I just have it laying around with a set of Morel hydraulic roller lifters and Harland-Sharp rockers. I m 62, I think I need to use this stuff up, 😆
Question i have a 5.7l ls with the 243 heads an .660 double valve spring with the tsp magic stick 4 cam. Is it possible to run a twin turbo setup on this package?
You vids are always informative !! Can you do a review of “chop” cams? A lot of people talk bad about them saying why would yo put a cam in just for the chop. Are you loosing power with a chop cam compared to other cams??
Im still learning too so i might be way off here but as I understand it, the "chop" is a byproduct if a high hp capable cam/engine so people associate that sound with that level of power. The cam doesn't run as smoothly down low because its designed for WOT performance instead. People have come to assume the chop is what creates the power since its usually present. Admittedly, that chop is very carnal and I'd love to have it in my Yukon but realistically, I know i dont need it.
a 500-hp turbo vs a 1000-hp turbo will change response rate much more than any change in AR in each of them. The relative AR changes with turbo since it based on the size
@@richardholdener1727 I was thinking more along the lines of if you had two 500hp turbos that had an A/R of say .63 and the 1000hp turbo had an A/R of say 1.16 the difference in A/R between the turbos might have more of an effect than say if you used two 600hp turbos that had the same A/R as the 1000hp turbo.
RICHARD WHAT IS THE RPM LIMIT ON A STOCK 5.4 2V F-150 MOTOR ? IM TALKING ABOUT THE ROTATING ASSY NOT VALVETRAIN. I REMEMBER SOMETHING SAID ABOUT THE CENTRIFUGAL FORCES NOT BEING GREAT ENOUGH TO PULL YOUR CRANK AND RODS APART BUT MOSTLY VALVETRAIN AND AIRFLOW BEING THE LIMITING FACTOR IS THAT RIGHT? LOVE YOUR CHANNEL,YOUR A WEALTH OF KNOWLEDGE. DO YOU EVER REST? NEIL Z.
how do you feel about compound turbos ? a smaller one to spin up fast then a big one to kick in and feed the air needs all hooked up to one exhaust system ?
Yes. I did that for my diesel Dodge Ram. I bought an aftermarket turbo when I was chasing a standing-mile speed record, and got a Borg turbo with 14 sq cm housing because I wanted to make as much top end power as I could. (3200 rpm being "top-end" for my Cummins.) Then when I started delivering travel trailers, I bought a 12 sq cm housing and swapped it out in a couple of hours. It was a noticeable change in exhaust temperature when I was climbing hills, but wasn't a night-and-day difference in lag.
The spool on my 88mm single turbo big block Chevy setup is incredible. It’s always in one form of downspool/upspool. I find myself modulating the throttle while driving just to change the pitch of it. And when the wastegate opens under boost, it’s incredible.
You can have your 2000rpm boost ,if you select an exhaust that will carry all the way through the RPM range . Gale Banks in the 80s would find a good starting point exhaust, then go up or down in size to find the perfect match . Usually testing three exhaust housings. Besides Peek power is boring! A car that increases with the pedal is WILD RIDE !!!
My complaint on turbos to much plumbing specifically oiling that mess seems to always leak second to much heat under the hood I am not a chicken on a roetesarey thirdly these things weigh more than you think some installations are worse than others off shore boats Definitely cars not so much and where is that 4 banger love Henry Miller wants to know lol
Turbo lag was a lot worse when they first put them into car's. Since they were originally designed for planes. Over the years they have designed a lot of it out.
I'm sure I'm not the only one to address #5, but here's my take on it. If you have an NA engine making 500 hp up against a turbo motor making 500 hp the lag will be the deciding factor. I think of turbo lag when comparing the little 4 bangers with boost against V-8's. Just my 2 cents.
Horsepower is torque over time. Tq x rpm / 5252 = hp. RPM is a time measurement. Why does that matter? Because two 500hp engines might not be equal. Making 500hp at 9000rpm is only 290ftlbs. 500hp at 5000rpm is a bit over 500ftlbs. 500hp at 3000rpm is around 900ftlbs. Do you see the trend? So lets say you have a 500hp sbc that is making that power at 6800rpm, and you are racing a car that weighs the same that is powered by a Pontiac making 500hp at 5000rpm. Now it comes down to gearing, stall, etc. If you gear the Pontiac the same way as the chevy(e.g. 4.10 - 4.88), it will be slower than the Pontiac would be with a gear that utilizes all that bottom end torque (like a 3.08 - 3.55) With the weight being the same and the gearing right for the power band, the Pontiac will get to the finish line first, because it is making a lot more torque and it moves the vehicle easier. In a daily driver the Pontiac is going to be a lot more fun, use less fuel (even if its a 455 vs a 350), and it will be easier to drive, because it is making plenty of power in the RPM range you normally drive on the street. The chevy will need more RPM to get things moving, more throttle angle, and it will have a profound disadvantage under 5000rpm. Then it will have a higher cruise RPM and its longevity will suffer as a result. You still need some RPM in drag racing, a 2000rpm Allison V12 will not ET very well despite it making over 1500hp. Land speed is different, and it changes with the surface you're racing on. Where in the RPM range an engine makes 500hp, and what gearing it has matters a great deal. Thats why a 400hp Pontiac 455 can run 12s with a 2.93 gear in a 4100lb GTO and the 500hp sbc probably won't be pulling a 4100lb vehicle that well as the sbc lacks torque. A 500hp Honda sure as hell isn't pulling 4100lbs into the 12s. The Pontiac is probably making well over 550ftlbs from 2000 to 4000 rpm. The fun thing is when you throw boost at an engine that is already making 650ftlbs from 3000 to 5000rpm. More on that when the 6-71 manifold and drive get here. I build somewhat silly daily drivers. I like both torque and horsepower, but I know that TQ makes HP, the higher the RPM range of the TQ the more HP the engine will have.
Ok so Here is What I found... EBAY cheap GT45 I created as much with one as with 2 however it should be noted that with one its working its ass off and I thought (like you pointed out)If I used 2 of the same turbos they would create the same boost with half the work... spool almost instantly and I have 78 passes on them 10.0 last Thursday 355 stock block forged internals 8.5 comp PUMP GAS !!!!!!
“Your have turbo lag until like 3000rpm” ok and your NA setup also doesn’t make any power below 3000 which, coincidentally, is what your converter stall speed and gear ratio are helping you with
I understand that the lower compression ratio concept has merit if you look at the larger combustion chamber volume at TDC as a way to fit more of the boosted fuel/air charge in the cylinder for combustion. As far as a "turbo" cam, I am sure that certain camshafts with more ideal valve timing events will work better than other cams. Turbo lag is an issue with certain driving conditions where the difference between tractability before boost is tolerable and just after boost arrives becomes intolerable (traction going through a corner for instance or accelerating on less than ideal surfaces). In drag-racing, which I partake in, turbo lag is a non-issue as one only needs to "power-brake" a turbo engine at the starting line to just start the boost curve before the green light. In this application, there is no reason to use a smaller compromising turbo. Turbo boosted engines, while generating more torque and HP, do so with less pressure spikes in the combustion so they typically are easier on the rotating assembly. Still, Forged pistons will tolerate the potentially higher combustion temperatures better under sustained boost conditions than cast pistons. This is the reason why engines designed for and with turbos usually have sodium-filled exhaust valves as well. They can handle the sustained higher temperatures much better than standard valves.
I get it that every cam is a boost cam, but what about cams with lots of overlap. I've always heard that wasn't good. And when I say lots of overlap, I don't mean a 230 @ .050 on a 112, I mean a cam like a 250/260 @ .050 with a 106lsa. Also, talking about packaging, which combo would make make more power reliably? A Turbo, intercooler on gas, or a non intercooled on e-85?
Yes any cam works, but "turbo" or "blower" cams might have been optimized for boosted applications and not just for outright power. Unless Comp Cams are lying by marketing some of their cams as "turbo" cams. Just like a shoes. You can use basketball shoes as running shoes, does not mean hiking shoes are optimized for running.
I bet you can't use the same cam in an LT1 as in an LTG 😂 All jokes aside, I'm a novice with understanding cams, what changes are better when you go with an aftermarket cam for an engine that is already turbod stock?
For myth 5, keep in mind you can also do a compound turbo setup which gives you the small turbo response plus the big power numbers... Have your cake and eat it too... As long as your cake isn't money cause it's way more money 🤣 I also have the same argument with supercharger guys. Yeah your boost lag is linear so you only hit peak boost at 7000 rpm where I'm at full boost at 3k or 4k. I will concede that it is harder to drive since it's nonlinear, but it just takes more practice to get accustomed to it.
I usta think "No replacement for displacement"......right up until I had a built turbo engine.
When boost hits, real boost...its like the Millennium Falcon in STAR WARS.
Great work as always, Richard !!
LS guru
Build that turbo engine with more displacement and you shoot down the MF in STAR WARS.
I hear ya, Jeff...
I have a 2017 SS Sedan with an LS3/6 spd Manual...wanna boost it.
Probably w/a 2650 Magnusson supercharger.
The one thing I want to mention on the concept of a turbo cam- turbo specific cam grinds were much more prevalent 30 years ago when high power turbo engines used less advanced turbo and turbine design which had higher backpressure. If they weren't careful with their cam timing and valve overlap, the increased back pressure would push exhaust back into the cylinder and you'd end up with a really weird curve and dropping power. Even nowadays it's not really a good idea to put a big overlap cam with a small turbo, if for no other reason than just turbo response. Basically, size your cam and turbo so they work with each other and you'll be fine.
BS
Every bit of that is truth! The first time I rode in my buddy's gto (5xx whp nah/7xx procharged) I was no longer an na guy. I thought it was fast before it even go into boost and man did it come ALIVE under boost 🤤. Stock bottom end except for arp hardware throughout and it had one hell of a top end. Changed my entire Outlook
Yeah, Boost will do that to you....
After you have the boost hit at 3000-6600, you’ll swear it’s a ScatPak. The key on older engines is a rising boost curve and a tune. If you are hitting a 50 year old block 600-700 ftlbs at 2000 will break it. You can have your cake and eat it too. 450ft lbs at 1500-2000 fine, hit 3000 and have 600-up to 750 to 6600, that’s cooking. A modern OD trans you will laugh your balls off at the new stuff when an old boomer car stays right with them or better. 😈
@@Bbbbad724 it was an 05 gto 6 speed car and it was in the 9s. It was one nasty car 🤤. I love classic muscle to though and never underestimate what's under someone's hood especially if I see radials or slicks. He sold it and I was furious lol
Lag is present in every turbocharged vehicle I have owned, but I have found that I adjust to it. I can go from my NA LS1 Camaro to my Dodge turbodiesel with no problem. It's just a matter of timing. On a turbocharged vehicle, I push down the accelerator a second sooner to get the torque when I want it.
I bought a Pontiac Sunbird turbo new in 1985 and drove it for 14 years. Full boost was achieved on that engine by 2500 rpm. I used to autocross it, and got used to keeping my throttle foot down while left-foot braking in the slow turns if engine speed got below the turbo. Opening the throttle helped keep the turbo up to speed.
The temptation is so hard to resist,you make it sound so easy. Thank you!!! you are a wealth of knowledge .👍
Turbo lag was much more of an issue back when turbo motors had low static compression ratios. When there was no boost they were real dogs. Today's boosted engines running higher C/R run pretty good even before the intake charge is pressurized when they are essentailly NA engines with restrictive exhausts (as the turbo does in fact impede exhaust flow).
It's nice to view a video from someone who actually knows something about turbos. I'm really tired of reading & watching videos and hearing the turbos are junk, turbo engines always blow apart, etc. A turbo-equipped engine can be very powerful and last for a long time IF the engine/turbo setup was designed well, and proper maintenance is performed regularly.
Man I have a myth busting combo, stock 280k 4.8 Silverado with a 67/65 .71ar turbo that I built to tow sees 7 psi at 1800 rpm under load and it's been alive for 6 years and 80k miles. Richard is preaching truth 🤙
Boost, compression, or timing. Pick 2. Fuel helps
I believe for turbo lag it is the response of the NA motor that people are missing. Some of this comes down to compression ratio and how good the motor itself is responsive without the turbo. Another is the time it takes the air to fill cylinders at the crack of the throttle opening。
I say build a good N/A but engine and use the turbo as your power added but build smart as you need to check your ring gaps. Also with your power in mind heat management along with tune is also key
#5 Turbo Lag: When high HP engines are built with a big turbo there is a certain rpm where it begins to make big power after the turbo spools up and produces boost. BUT... a high HP N/A engine ALSO needs rpm to make big power as they rarely make power or torque down low. So, although an N/A engine doesn't have "turbo lag" it does sorta have "power lag". Pretty much the same thing.
Internal combustion engines are lag machines yeah but the situation is waaaaaaay worse with a turbo on a race track. Thanks to gears you can always keep the na motor at powerband in a track but with turbo when you let off the gas all the boost is gone and you have to wait again to get that boost regardless of your rpm. No such thing in an na motor
@@288gto7 I m running a 4.33 Locker with a manual VB C6.
I also have a 428 crank and 9.5:1 pistons.
I agree Rich, I want a VS 7875 with iron logs tied together and the air filter at the headlight bucket and the hot exit straight out the side about 18 in of 4 inch. I may have a intercooler I can get. Air/ water with windshield wiper fluid in it for 12 lbs boost. It is a 105 block that bitted 3/16 4.09x 3.98 around 420ci with .170 walls. It should be 750 at the tires. The 394 in the car NA will burn 16x8 60 series until I let up. The neighbors hate that when I do that and get out with my white cane and walk in the house.
BTW, what are you running Rich? You have a 427 BBM?
I remember how the low compression myth made so many honda guys build REALLY crappy engines with like 8:1 compression. I think the main reason was tuning back in the late 90's and early 2000's was super primitive so the tuning margins were awful. Someone on honda-tech built something like a 14:1 turbo build to disprove the myth and good god did it make power. Per pound of boost the gains it was seeing was INCREDIBLE. I think what ended up happening was the piston pins bent, pistons kissed head, engine went boom. It wasn't due to tuning or compression, was just reaching the limits of the components it was built with.
I’m constantly surprised how much we think alike! I’ve always laughed about that “Turbo Lag” myth!! ,..And also the measurements if BOOST IN POUNDS ,..actually being not what you’re boosting the engine, rather how much it’s NOT USING 😀. It’s comical how many people haven’t realized these two VERY IMPORTANT facts!!
Best Video on TH-cam! This is exactly the information I needed compiled into a single video. Thank you for everything you do to educate us.
Glad it was helpful!
Myth 5 is why I went ecoboost in my new truck over the 5.0. People were saying you had to rev the ecoboost to the moon to pull a trailer, when its actually the opposite. The 5.0 doesnt make even good torque until 4000, and the ecoboost is well beyond the 5.0 max torque as low as 2800. I tow my trailers under 4000rpm on the ecoboost. But my 5.0 Constantly sees redline for the same acceleration.
One your best/most helpful ones yet . I'm back and forth going turbo from a hard charging procharger sbf . Fast efi and all the goodies to twist it up high. That kind of a hard spend these days to change it but you about got me convinced. Til next time bud
Thought that was the point, make the same at 6000rpm as 7500rpm? Feel free to disagree! Batting it round now! But, a shot of gas once in a while seems cheaper, especially since I have a hundred shot here! Maybe I'm not aiming high enough, but how much can your chassis take without up grades! You'll never outrun the dope dealers!
Turbo lag is what happens when you are in boost and lift off and go back in boost
What is commonly refered to as "turbo lag" is the boost threshold, which should really be vaccuum threshold because thats when you make full boost.
I'm glad somebody understands..... Rich touched on that idea for a quick second on one of his vids, but never really followed up on the idea. Yes, boost response depending on turbo size on an engine dyno are one thing..... But how they work on the street with a manual transmission are totally different... Even factoring in perfect tuning with your BOV('s)
@@bradywebb1311 true, moving from a stock transmission to an h pattern dogbox reduced lag, then moving to a sequential pretty much made it disappear to the naked eye on the boost gauge.
@@kkmfc3s I mean.... Anything you do to reduce shift time will reduce perceived lag. But, I'm talking about us normal guys that don't want to spend $15K on a transmission. Might as well put an automatic in it and be done... I like a good ole fashioned clutch with some synchros to blow up... 😁
@@bradywebb1311 yes even moving to an automatic will help, it won't unload the motor during shifts. For me it was necessary to meet my power goals and still have the car work on the road course, kill lag and have close ratio's to keep the engine in the powerband. Even the previous 5k h pattern dogbox was massive improvement over stock.
@@bradywebb1311 IF you don't Granny shift a Standard you don't lose boost. You will build boost if you power shift.
In response to myth #1, I always see a lot of focus on choosing the right turbo by looking at compressor maps. But how do you go about choosing the right turbine size being that theres a lot of turbos that come with the same compressor but different turbines? Are there calculations to figure out the exhaust flow of a given engine combo?
there are turbine maps too (kind of)
Turbo manufacturers make turbine maps all the time, but they're not easy to interpret for applying to engines. The problem is the pulsed flow that comes from the exhaust port. Pressure pulsations in the turbine housing make the turbine operate at different points on the map depending on what part of the engine cycle is occurring from millisecond to millisecond. In order to calculate a match point for flow on a turbine map, you would need to have dynamic pressure data within the turbine housing, and do a time average of flow for an engine cycle to know where it is operating.
@@andyharman3022 That makes perfect sense. I never though about the pulsing nature of the exhaust. That being said, when choosing a turbine do you just talk to a expert that has previous experience? Or is there a way to at least make an educated guess?
@@THEMADTYPH00N Talk to experts that have experience in turbo matching and be sure of what you want your turbo system to do. I you're running standing-mile or Bonneville, you can accept more lag to get more top-end power by having lower exhaust pressure. If you're doing 1/8th-mile drags you need to get off the line hard and can't accept a lot of lag. And don't just talk to one expert, talk to a few.
@@THEMADTYPH00N yes you can calculate the expected air flow your engine flows and size the turbo accordingly but having said that no graph or chart compares with real world testing and experience as numbers don’t always give the best driving results
As someone who just finished my Single 88mm turbo build on a 10.6:1 496 Big Block Chevy, I can confirm most of these myths are false. Higher compression and boost are great together and I’m at full boost around 3200rpm. With big block torque, the lag doesn’t really exist, you’re already smashed in the seat anyway.
He’s taking about a 4.8 liter lol a 496 is totally different so therefor nothing he’s saying is false ? That’s like comparing a 2.0t to a 4.8l lol
I broke a Pontiac 400 crank in half
Front 2 rods and the front half of the crank right out the back of a 77 trans am at the drag strip back in the late 80s that car ran 11.01 . Best aways right there 02 or 03 never that 10.99 . Last night of the season it kept giving the distributor a little . Then a little more . No timing light . Then one more time. She left and was on a mission slammed second at 6800 ish and let her eat to the traps just before the traps at around 7000 she just about took the hood off. It buckled the hood up you could put your arm in over the fender with it still closed . It was dumb but amazing. Back then grab another 400 off the garage floor and be back at the track on Wednesday
I love your philosophy: NA cars have lag 100% of the time. I have never owned a V8 with forced induction, but I have owned an NA LS, supercharged V6's and turbo 4's. I had a wrx with a 71 lb turbo, cams, ported heads, big front mount ic (opposed to top mount that are the norm on subies), and water meth etc. Many of the guys I knew that had wrx/sti were always concerned with turbo lag, yet wanted big power. They wanted tiny hot sides and small top mount intercoolers and then wanted 20+ psi. Basically, crazy backpressure, higher intake and underhood temps and a limited top end. Roll raced like a half dozen other subies set up like this and the result was always the same, they never pulled away on the small end and I gapped them bad on the top end. Turbo lag was never an issue ever.
Hi Richard here is an Idea 💡 not sure it would work but here you go. The thought is take the inside door Condenser and run the hot air across the coils witch will hopefully cool it down hopefully. I'm not even sure it will make sense. But its just an idea 💡.
The higher the compression the more duration and also higher overlap you can run. You can use the overlap to bleed off cylinder pressure.
Mazda does it on 16:1 compression with boost.. well with some tricks like ultra lean afr and a richer pocket to ignite near spark plug
Richard! I was under the impression that lower center line cams ( say 106 vs 112) do not maximize the turbo efficiency per se. Yes a 106 center line will work but the wider center was a better choice for the turbo
I still find guys on Facebook saying a turbo cam is necessary. What it really stims from is DCR, which falls more in line with your high compression myth. Most "Turbo" cams are the same as their N/A counterparts with a wider lobe separation. Specifically they'll retard the Intake center line to lower the dynamic compression of the motor. Again, increasing your tuning window. This is also why some cams will recommend a compression ratio. Because they know that big cams kill DCR (and therefore torque) so they tell you to run more compression to make up for the fact.
just look at the na power curve
My bone stock vr6 has an hx35 on 9psi of boost with e85 and man does it love life! 10.7ish:1 comp. Also, if I’m doing 80 in 5th gear, about 3500rpm, full boost when I mat it! Car also has an extremely efficient water to air inter cooler and man does it work! Ambient temps can be about 85 degrees and iats are about 90-100.
11:30 I think the myth of turbo lag comes from people confusing boost threshold vs boost lag. Boost threshold is the point at which your engine is able to produce boost, vs lag which is the delay when you're at your boost threshold and you go from an off throttle state, back onto the throttle. A responsive turbo will still not reach peak boost till it hits a certain rpm, but it's off/on boost response will be better than a larger turbo. boost threshold is flooring it at 2k and seeing when the engine finally is able to spool up the turbo and make power.
I want an all aluminum 427 Windsor motor with kasse p38 heads. They are good for 750 horsepower and 600 lb/feet of torque......and no lag. They will also run on pump gas and have hydraulic lifters so valve lash adjustments don't need to be made. Plus, I love the sound of the stroker with a snappy cam profile.
Just a thought.
HE DOES GOOD STUFF
Need instant power put a blower on it. Max power use a turbo. Thank you for all the data!!
My 2003 Audi RS6 has boost immediately, but I am sure those little turbos run out of steam up top, but sure is fun from a dig.
LTG community strongly believes in having forged internals. Nobody really wants to touch the engine without extreme expense, which just makes it less reasonable to competitor options from BMW or Audi. I think, just as you said, it could really benefit from proper ring gap to deal with higher turbo.
Mr. Richard your video was clear and concise, but i still have questions and comments.
1. Would it be logically better to size a turbo according to double the CFM of air an engine could breath? Or am i just complicating things?
2. I agree with the compression ratio comment and in the future I'm gonna build forged bottom ends with the OEM compression ratio.
3. I learned that with turbo engines you want to minimize the valve overlap. A cam made with a reduced overlap compared to an OEM N/A cam is considered a "turbo cam". Is that correct?
4. "Turbo lag" is actually boost threshold per Maximum Boost 💪
DO NOT MINIMIZE OVERLAP-THAT IS A MYTH. DO NOT CHOSE A TURBO BASED ON DOUBLE AIRFLOW OF NA MOTOR-JUST PICK THE TURBO SIZE BASED ON DESIRED OUTPUT (EXAMPLE 700 HP),
@@richardholdener1727 understood. Thanks for your replies and your service to the car community🏆💪
Beautiful, absolutely awesome. I can't wait to boost my gen iv 6.0 sierra. I've never seen you do an hx35 turbo on a ls. Maybe more content to come:)? They are cheap and pretty easy to come by. It not a big turbo but it's also not super small. Makes a guy wonder what he may get? Maybe even do a 5 nitrous myths.. ha!
Richard, I agree that any cam is a turbo cam. Also, any cam is a centrifugal supercharger cam. In both cases the device used to provide boost is a compressor. However, a roots style blower is not a compressor. Boost is produced in the cylinder so, I wonder if the timing of the intake valve closing event affects boost. My question is, does the cam matter with a roots blower?
A ROOTS BLOWER ADDS POWER TO WHATEVER IS THERE NA AND CHANGES THE CURVE AS DESCRIBED IN THE VID (SHORT RUNNER)
I think you'll develop a greater sensitivity to turbo lag if you try daily driving the Omni with the 2.2t and the manual transmission.
Richard I've been watching for years and was wanting to see something on spark plug gap's and ignitions. What can be gained from MSD over the stock system. Be nice to see it on the Dyno or if you have any I somehow missed it.
SEE THE PLUG GAP, PLUG INDEXING AND PLUG HEAT RANGE VIDEOS ALREADY UP
PREACH! I proudly attend the church of Holdener!
I find it interesting these 'myths' that are 'common knowledge' with machine shops around the country, always have no beginning basis, but often are touted as truth, with the speaker of the myth claiming you will destroy yourself (your engine) if you don't listen to them. Same concept with low compression being a necessity for a towing motor. I have been running 11:1 comp in a BBF for years now, with no issues. Yet, every machine shop always told me I would destroy my truck by blowing up the motor and having a major wreck wherever I go if I dared to go further than 9:1... Finally I just quit saying what I was building until after I built it, so I didn't have to take a brow beating...
Thanks for clearing this up.i been saying to myself for the longest. Now I hear you talk about ring gap a lot can you explain what this does and how it's better . maybe I missed the video of this explanation.
YOU NEED MORE RING GAP WITH BOOST-OR IT BREAKS THE RINGLAND ON THE PISTON
So looking forward to getting my GTP turbo kit!!Twincharged GTP baby
Not that I don’t agree , but depending on boost - then overlap ?
So have you see , bisimoto’s d16 cam Independently tested and gained 50 hp or so than the next top cam
NO IDEA WHAT YOU ARE TRYING TO SAY HERE
Moment of Inertia. That is why two small turbos can have less lag than one large one. Smaller diameter compressor and turbine wheels have less resistance to angular acceleration. Moment of Inertia increases with the 4th power of the diameter, so if the wheels of the two 500 hp turbos have 20% smaller diameter than the wheels of the single 1000 hp turbo, they will have 41% of the rotational inertia. But rotational inertia is not the only determinant of how much lag a system will have. Turbine housing throat area also has a lot to do with it, as do cam specs, induction system volume, and exhaust manifold design.
THE RESPONSE RATE OF THE TURTBO (AS YOU KNOW) HAS MUCH LESS TO DO WITH WHEEL WEIGHT AND INERTIA-IT HAS TO DO WITH EXHAUST ENERGY
@@richardholdener1727 Energy is the major input to the system that is mostly controlled by the driver's right foot. Mass flow of air and burning fuel increasing the exhaust temperature. Inertia of the turbo wheels absorbs power from the exhaust stream and is resistance for accelerating the turbo.
Another factor that twin turbos can have in their favor is the elimination of the crossover pipe that a single turbo would have on a V-type engine. Keeping the pipe runs short reduces heat loss before the turbine.
great video, very informative. appreciate the organization too.
Hey Richard. Basically we should pick the best NA cam and go with that? I saw your test on overlap/lsa and how that was not a significant factor when going with boost.
Volvo s40 t5 had 230 ft/lbs at 1800 rpm. Man that was fun in AWD
Yes , I am pretty sure I have hair under the hood. Please include helpful tip .
I wish you would explain why camshaft manufacturers or regrind companies even make turbo camshafts and the main reason is to stop exhaust reversion. so if you have a crazy high lift cam with a shitload of overlap... you can only run a little bit of boost before you run into reversion. But up until you get to that point the turbo will be super responsive and then you'll hit a wall and if you try to push through the wall you'll blow it up. Maybe I'm wrong but that's how it was explained to me please correct me if I'm wrong.
that is not correct-boost does not flow through to the exhaust (because exhaust has higher pressure than intake) stop worrying about overlap-it is your friend for making power
@@richardholdener1727 Reversion is exhaust flowing into the intake port during overlap...
Please reply can I make 600 without forged and daily drive.
yes-with boost
@ ok so I will be safe on stock internals?
thinking about slapping a turbo on my cammed , 11:1 LQ9 with 93 and a water meth kit
Lots of Instagram turbo builds have "hot" air intake, where the turbo just has a bellmout, no filter, breathing in under-hood air.
The turbo Corvairs ran 6.5 to 1 for compression ratio. These are cars from the '69s and they worked just fine. In fact, they had more torque, especially in the low rpms. Weird but they were the best torque producers out of those air-cooled motors.
they would make more torque with 7.5 or 8.5:1
Is a remote turbo like we were talking about earlier equal to under hood ones. I was thinking of a 950 hp turbo in front of the rear wheel with my headers and a crossover behind the headers the pipe going back to feed the turbo a 2.5 and runs a pipe to the front intercooler right at the front tq box and up to the bonnet. I have been thinking about it the two ways, will a 7875 VS work for either?
it doesn't matter where it is located
@@richardholdener1727 Thank you!
How much cooling can an air only inter cooler provide? How much cooling can a rich fuel mixture provide? Degrees in Degrees out at one bar? Great video
Higher compression means better fuel. Richard doesn't find many benefits to using methanol injection (everyone else does) but this is when that would be a great addition
it helps to suppress detonation but does not add power
Hi, great info, really appreciate it. I'm trying to figure out the best setup for a marinized 454 that I have running a jet unit in a boat. I found some old gale banks water cooled exhaust manifolds here in New Zealand, which was rare...so I need to figure out the best twin turbo setup....the jet unit can't go past 3500 rpm so I need max power/torque at around 2700-3000rpm which I know is a big ask....any recommendations for which turbos to use? Thanks
twin gt3582 will spool immediately with a decent
Great thanks 👍
I'm confused, Dr. Holdener - please help...
Twin GT35 setup/LQ4 6.0...
E85 is not readily available where I live - Detonation is a real concern for me.
Should I run my 317 heads, bc they offer lower compression? I have a set of 826 heads which will provide more power but...
500 wheel, street fun is all I care about - not max effort.
use 317
@@richardholdener1727 Thanks Doc!
People lost their minds when I decided to run my stock bottom end lq4 with ls3 top end and a "stage 4" summit cam to 7500rpm. Nobody had any reason as to why I COULDN'T.
Its fine. Done a ton of passes (N/A). Can't wait to get my GT45 on this beast, as Holdner said about the N/A combo, trap speeds equate to around 500hp at the crank... For a motor build that cost $1500cdn lol
Trying to get into the 8's with a 4th gen firebird, will be following Holdner's advice the entire way :)
LS3 HEADS ON A 6.0L WITH A CAM WORKS WELL
Test the 4.7 that came in jeep dodge and Mitsubishi....... They are just like the 4.6 Ford..... The initial run of the 4.7 engines started with only 235 horsepower the last 4.7 produced 335 hp manufacturer increased horsepower drastically over the years.
Hey Richard is it possible for you to do something on a lsa setup. Like what cams would work best since each blower response differently
each blower does not respond differently-just pick a cam that does well na-it does the same thing under boost
Hi Richard, so according to your video I can build my twin turbo Jaguar V12 engine with the stock 11.5 CR pistons? This should be expensively interesting! Shall I give it a go? Or do you advise going for lower CR with custom pistons? Stock rods and the stock steel cranks are unbreakable in these engines so I'll leave them be. What are your thoughts?
My ls2 corvette is 185k miles and climbing, hope to be able to boost it soon (a&a supercharger). If it dies it dies
What about the older buick grand national turbo engines? They had a stock CR of 8.1:1 and detonation was/is still a big obstacle for them to overcome without adding alky, or e85. Can you dive more into the turbocharged engines from 80's buicks? Any up to date solutions to running a higher CR, and not worrying about detonation? Maybe e85 is the solution?
i covered the need for octane
@@richardholdener1727 what about tuning? Will a holley efi controller work with the grand national v6?
Hey Rich, recently came across your channel and am enjoying all your fact based educational content! If you ever see one in the junk yard, I'd love to see you do a Big Bang on the Toyota/Lexus 1UZ. I know there's not much after market for it, and the stock cams don't offer much top end, but I'd still like to see what they can take/make on max boost!
There’s a guy making I believe 1150 on stock cams
On a 5.3 truck motor do you absolutely have to ring gap if you're only looking to turbo it up to around 650hp? Or is ring gap only absolutely needed if you're looking at super high hp?
YOU DON'T KNNOW WHAT IT IS IF YOU DON'T CHECK-SO YOU TAKE YOUR CHANCE
If you were to build a boosted motor combination that would come into boost at 2500RPM, lets say a 4.8 what turbo would you use? Would it still be the classic GT45 maybe with some high compression pistons, long headers and a neat cam ?
WOULD NOT USE THE GT45 ON THAT
@@richardholdener1727 Would a small responsive 65MM turbo/ T4 turbo do, in terms of response
I have a question about LSA in a cam and it's effect on boost response. Reason being is I remember reading an article where Kenny Duttweiler (I believe) was saying his ideal turbo cam had a tight LSA and a reverse split duration, but all cam companies' off the shelf "turbo" grinds are usually single pattern with a wide LSA. So who is right?
that is not absolute for every turbo motor
I don't think it is so much a question of can you make a specific cam that works better with a turbo, as much as it is a question of will all cams work with a turbo. You could ask the same question about can you make a better cam to work with N/A CNC ported Brodix heads than the stock heads? Everything can be tweaked and tailored to get that little bit more out of it. The question you have to ask yourself is it worth all the R&D time and money over what is already available?
I'm cool... I'm not running stock anything when adding a turbocharger. I'll get me a turbo cam and be happy.
Camshaft you cannot run with a turbo?
/Cam with a bad bearing journal?
(didn't specify you needed to be able to run it non turbo).
What about my 245 on both sides @.050 and.600 lift on a 110 hydraulic roller cam? I have a 428 iron crank and forged stock 5140 forged rods with ARP bolts.
YOU DON'T NEED THAT MUCH CAM-BUT IT WILL WORK
@@richardholdener1727 I just have it laying around with a set of Morel hydraulic roller lifters and Harland-Sharp rockers. I m 62, I think I need to use this stuff up, 😆
@@richardholdener1727 I got to thinking maybe Scnieder could regrind the cam to 235/245
Hi Richard when are you doing ford 302 P-V clearance part 2 AFR heads...
Thanks for videos:)
I will post after I do the vid
Question i have a 5.7l ls with the 243 heads an .660 double valve spring with the tsp magic stick 4 cam. Is it possible to run a twin turbo setup on this package?
yes-but you don't need that much cam with turbos
Good information thanks for sharing
You vids are always informative !! Can you do a review of “chop” cams? A lot of people talk bad about them saying why would yo put a cam in just for the chop. Are you loosing power with a chop cam compared to other cams??
Im still learning too so i might be way off here but as I understand it, the "chop" is a byproduct if a high hp capable cam/engine so people associate that sound with that level of power. The cam doesn't run as smoothly down low because its designed for WOT performance instead. People have come to assume the chop is what creates the power since its usually present. Admittedly, that chop is very carnal and I'd love to have it in my Yukon but realistically, I know i dont need it.
Richard wouldn't the exhaust A/R housing have more of a bearing on the response rate than the hp potential of the turbos?
a 500-hp turbo vs a 1000-hp turbo will change response rate much more than any change in AR in each of them. The relative AR changes with turbo since it based on the size
@@richardholdener1727 I was thinking more along the lines of if you had two 500hp turbos that had an A/R of say .63 and the 1000hp turbo had an A/R of say 1.16 the difference in A/R between the turbos might have more of an effect than say if you used two 600hp turbos that had the same A/R as the 1000hp turbo.
Camshaft with zero lift might not work with a turbo. I've seen a couple. 😎
But we custom grind those....Not sold to the general racer lol!
RICHARD WHAT IS THE RPM LIMIT ON A STOCK 5.4 2V F-150 MOTOR ? IM TALKING ABOUT THE ROTATING ASSY NOT VALVETRAIN. I REMEMBER SOMETHING SAID ABOUT THE CENTRIFUGAL FORCES NOT BEING GREAT ENOUGH TO PULL YOUR CRANK AND RODS APART BUT MOSTLY VALVETRAIN AND AIRFLOW BEING THE LIMITING FACTOR IS THAT RIGHT? LOVE YOUR CHANNEL,YOUR A WEALTH OF KNOWLEDGE. DO YOU EVER REST? NEIL Z.
VALVE TRAIN IS THE KEY TO RPM-i DON'T KNOW WHAT THE CRANK, RODS AND PISTONS WILL DO
how do you feel about compound turbos ? a smaller one to spin up fast then a big one to kick in and feed the air needs all hooked up to one exhaust system ?
I have compound turbo vids up-but you are thinking about sequential turbos
Cant you change the hot side housing to better suit your application? If you have too large a housing say and you want more response?
Yes. I did that for my diesel Dodge Ram. I bought an aftermarket turbo when I was chasing a standing-mile speed record, and got a Borg turbo with 14 sq cm housing because I wanted to make as much top end power as I could. (3200 rpm being "top-end" for my Cummins.) Then when I started delivering travel trailers, I bought a 12 sq cm housing and swapped it out in a couple of hours. It was a noticeable change in exhaust temperature when I was climbing hills, but wasn't a night-and-day difference in lag.
@@andyharman3022 my old 12 valve had a super laggy 18cm housing it was a dog till almost max rpm then I got a 12cm and it was night and day.
another great video with accurate info!!
So a 302 on e85 with 8.5:1 compression running 12lbs of boost I shouldn’t need to run an intercooler?
should always run an intercooler
Hey how are you. Ive been looking for a GLHT FOR YEARS. Please let me know if you know of any for sale. Thank you
Really good discussion, sir. Best wishes, Corky Bell
you created a channel just to post a comment as Corky?
I choose Turbos.. by which one has the Loudest Whistle.. it's really the only way to roll.
The spool on my 88mm single turbo big block Chevy setup is incredible. It’s always in one form of downspool/upspool. I find myself modulating the throttle while driving just to change the pitch of it. And when the wastegate opens under boost, it’s incredible.
I'd like 2 medium turbos to go, please.
You can have your 2000rpm boost ,if you select an exhaust that will carry all the way through the RPM range . Gale Banks in the 80s would find a good starting point exhaust, then go up or down in size to find the perfect match . Usually testing three exhaust housings. Besides Peek power is boring! A car that increases with the pedal is WILD RIDE !!!
My complaint on turbos to much plumbing specifically oiling that mess seems to always leak second to much heat under the hood I am not a chicken on a roetesarey thirdly these things weigh more than you think some installations are worse than others off shore boats Definitely cars not so much and where is that 4 banger love Henry Miller wants to know lol
Turbo lag was a lot worse when they first put them into car's. Since they were originally designed for planes. Over the years they have designed a lot of it out.
Are coyote engines more responsive to twin turbos because of their ability to change cam timing.
you might be able to adjust cam timing to help
I'm sure I'm not the only one to address #5, but here's my take on it. If you have an NA engine making 500 hp up against a turbo motor making 500 hp the lag will be the deciding factor. I think of turbo lag when comparing the little 4 bangers with boost against V-8's. Just my 2 cents.
Horsepower is torque over time. Tq x rpm / 5252 = hp. RPM is a time measurement. Why does that matter? Because two 500hp engines might not be equal. Making 500hp at 9000rpm is only 290ftlbs. 500hp at 5000rpm is a bit over 500ftlbs. 500hp at 3000rpm is around 900ftlbs. Do you see the trend?
So lets say you have a 500hp sbc that is making that power at 6800rpm, and you are racing a car that weighs the same that is powered by a Pontiac making 500hp at 5000rpm. Now it comes down to gearing, stall, etc. If you gear the Pontiac the same way as the chevy(e.g. 4.10 - 4.88), it will be slower than the Pontiac would be with a gear that utilizes all that bottom end torque (like a 3.08 - 3.55) With the weight being the same and the gearing right for the power band, the Pontiac will get to the finish line first, because it is making a lot more torque and it moves the vehicle easier.
In a daily driver the Pontiac is going to be a lot more fun, use less fuel (even if its a 455 vs a 350), and it will be easier to drive, because it is making plenty of power in the RPM range you normally drive on the street. The chevy will need more RPM to get things moving, more throttle angle, and it will have a profound disadvantage under 5000rpm. Then it will have a higher cruise RPM and its longevity will suffer as a result.
You still need some RPM in drag racing, a 2000rpm Allison V12 will not ET very well despite it making over 1500hp. Land speed is different, and it changes with the surface you're racing on.
Where in the RPM range an engine makes 500hp, and what gearing it has matters a great deal. Thats why a 400hp Pontiac 455 can run 12s with a 2.93 gear in a 4100lb GTO and the 500hp sbc probably won't be pulling a 4100lb vehicle that well as the sbc lacks torque. A 500hp Honda sure as hell isn't pulling 4100lbs into the 12s. The Pontiac is probably making well over 550ftlbs from 2000 to 4000 rpm.
The fun thing is when you throw boost at an engine that is already making 650ftlbs from 3000 to 5000rpm. More on that when the 6-71 manifold and drive get here. I build somewhat silly daily drivers.
I like both torque and horsepower, but I know that TQ makes HP, the higher the RPM range of the TQ the more HP the engine will have.
Ok so Here is What I found... EBAY cheap GT45 I created as much with one as with 2 however it should be noted that with one its working its ass off and I thought (like you pointed out)If I used 2 of the same turbos they would create the same boost with half the work... spool almost instantly and I have 78 passes on them 10.0 last Thursday 355 stock block forged internals 8.5 comp PUMP GAS !!!!!!
SPOOL SHOULD BE MUCH WORSE WITH 2 COMPARED TO 1
“Your have turbo lag until like 3000rpm” ok and your NA setup also doesn’t make any power below 3000 which, coincidentally, is what your converter stall speed and gear ratio are helping you with
I understand that the lower compression ratio concept has merit if you look at the larger combustion chamber volume at TDC as a way to fit more of the boosted fuel/air charge in the cylinder for combustion.
As far as a "turbo" cam, I am sure that certain camshafts with more ideal valve timing events will work better than other cams.
Turbo lag is an issue with certain driving conditions where the difference between tractability before boost is tolerable and just after boost arrives becomes intolerable (traction going through a corner for instance or accelerating on less than ideal surfaces). In drag-racing, which I partake in, turbo lag is a non-issue as one only needs to "power-brake" a turbo engine at the starting line to just start the boost curve before the green light. In this application, there is no reason to use a smaller compromising turbo.
Turbo boosted engines, while generating more torque and HP, do so with less pressure spikes in the combustion so they typically are easier on the rotating assembly. Still, Forged pistons will tolerate the potentially higher combustion temperatures better under sustained boost conditions than cast pistons. This is the reason why engines designed for and with turbos usually have sodium-filled exhaust valves as well. They can handle the sustained higher temperatures much better than standard valves.
How Much Maintenance Does a Turbo Take . & 0r . a Pro Charger
MINIMAL
I want to build a stump pulling 455 Olds and boost it.
I put 150mm on a dodge power maxx along time ago!!!💣💣💣💣💥💥💥💥
I get it that every cam is a boost cam, but what about cams with lots of overlap. I've always heard that wasn't good. And when I say lots of overlap, I don't mean a 230 @ .050 on a 112, I mean a cam like a 250/260 @ .050 with a 106lsa.
Also, talking about packaging, which combo would make make more power reliably? A Turbo, intercooler on gas, or a non intercooled on e-85?
a turbo with ic on e85. any you don't need a big cam with a turbo, forget about the overlap-it will just soften the response rate
Yes any cam works, but "turbo" or "blower" cams might have been optimized for boosted applications and not just for outright power. Unless Comp Cams are lying by marketing some of their cams as "turbo" cams.
Just like a shoes. You can use basketball shoes as running shoes, does not mean hiking shoes are optimized for running.
keep listening to what is being said-you will get it
I bet you can't use the same cam in an LT1 as in an LTG 😂
All jokes aside, I'm a novice with understanding cams, what changes are better when you go with an aftermarket cam for an engine that is already turbod stock?
IF THE CAM ADDS POWER NA-IT ADDS POWER UNDER BOOST
For myth 5, keep in mind you can also do a compound turbo setup which gives you the small turbo response plus the big power numbers... Have your cake and eat it too... As long as your cake isn't money cause it's way more money 🤣
I also have the same argument with supercharger guys. Yeah your boost lag is linear so you only hit peak boost at 7000 rpm where I'm at full boost at 3k or 4k. I will concede that it is harder to drive since it's nonlinear, but it just takes more practice to get accustomed to it.