S3 E28. Performance tuning and MPG tuning the 670cc predator powered Renault
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- เผยแพร่เมื่อ 19 ส.ค. 2023
- Season 3 Episode 28. Jimbo tests various modifications in order to maximize performance and fuel economy on the 670cc predator powered Renault. Can Jimbo get the Renault to go faster and save fuel at the same time....? Tune in and check it out.
Hi Ya folks! Beware of a GIVEAWAY SCAM. This channel is NOT doing a Giveaway and we are NOT asking for personal information. If you get a message asking for info, please ignore it.
Jimbo
The walls in our new studio are bare, if you want to send swag please send it to:
Robot Cantina
207 S. Sedgwick Ave
P.O. Box 28
Haven KS, 67543 - ยานยนต์และพาหนะ
This IS the only channel on TH-cam with this kind of content.
It's amazing, i love it
Aging wheels I like a lot too.
that is a fact
Cars and cameras is like it's crazy cousin
Hartwick performance there is a kid trying to put a 2 stroke v8 from a boat into and old Datsun! Just clips of him working tho, not edited into episodes like this channel!
Robot Cantina: I hate doing fuel economy tests!
Proceeds to do 5 fuel economy tests in one video.
I wonder if some kind of a flow meter could be used to get instant fuel use reading. That would save a lot of time.
@@krashanb5767i would assume the number would not be reliable much, since the test is supposedly measured in distance to fuel ratio. Usually after a trip of driving (somewhat) normally. Instant read fuel consumption is not really telling much if at all
Since it's going to be well over 100 F (which in metric, is a different number) for the next week in KS, I don't expect we'll get any more fuel economy tests since there's no AC in that car. I guess he wanted to get all that testing out of way while he could.
@krashanb5767 He could put a weight cell under the fuel tank, check the odometer before and after, check the weight of the fuel tank before and after the economy test.
@@martin-vv9lf its called a load cell, but that's a fairly good idea.
The saturn turbo diesel is the most incredible car ever ! ❤
I'd like to diesel swap a Geo Metro. I would have thought the D722 was too small, even as the Metro weighs 600 pounds less than the Saturn
You know, its current acceleration makes it a perfectly acceptable "around town" driver that would beat the pants off most cars for gas mileage. I really like this little car. :)
I was wondering how close it was getting to the stock car too
@@pleasedontwatchthese9593the stock 1.3 has about 47hp, but the 670s a tad lighter, so i bet it can match it, especially if Jimbo does some CVT magic
I'd cruise around in it for sure!
I like all of the work he's done to it and I love the car at one point I would call it good a cold air intake would have been better than ram Air at that one
Point .
@@goosenotmaverick1156the 44 mpg he gets is all country highway driving, but i bet city is still 35+ mpg
I'm very jealous that you can spent your time working on these projects. Thanks for documenting the fun and sharing with us!
I drive an Excursion, and after seeing all the fun with this car it makes me want to consider something tiny to tinker on.
I wish i had more money. I'd love to f#ck around and find out stuff on my escort.
Tiny light car are superior
@@puebespuebes8589 now fitting in one is the next challenge!
@@HammerWrench ahah🤣 im french and i drive a voiture sans permis ( car whitout liscence )
I relate to your video dearly !!
Small car ( for european standart ), no more than 70km/h downhill, no fuel gauge ! fwd cvt and no climate vent... In southern France !
So i drive slowly but surely windows opened and arm out and it fit everywhere !
@@puebespuebes8589 your description makes it like I can almost see it happening! I drive an 8000lb Excursion with a V10 engine in South Georgia, USA. It loves towing and the gas station. When my windows are down, it’s to hear that exhaust singing! Our sons are 6’4” and 6’5” tall, so they appreciate the legroom in the second row.
Thanks for the recap of the progress so far. It's hard to believe you've been able to make such an improvement with relatively little modification.
I totally understand wanting to tune the engine performance before tuning the transmission. The engine develops the power according to the load, while the transmission converts it to the appropriate torque for the current speed. The tuning of the transmission will greatly depend on the power curve of the engine, whereas getting power out of the engine is its own thing. And whatever you do, you don't want to change a bunch of things at once, otherwise you won't know what change made the difference.
Exactly!
@@robotcantina8957as you are not losing traction and the car is light, would it be allowed to use motorcycle tires? There should be more slim options and also aerodynamic ones - would that be cheaper and legal? No saying it is worth it, just wondering if it is an option 🤔🤓
@@TheStuartstardustYou can't mount moto tires on car rims - the beadlock is entirely different due to the lateral forces the tire must endure. They're also generally heavier than an equivalent-size car tire, because of all the reinforcement necessary.
@@lr0dy bead might be issue yes, but you can the other way around? BMW has a motorcycle with a sidecar which use car tyres, some others also. Also ryan f9/fortnine had an episode about tyres where he mounted car tyre on a motorcycle 🏍️
@@TheStuartstardust The bead of a car tire is somewhat smaller than the bead of a bike tire, if I remember correctly, meaning a car tire can fit onto a bike rim. It's a stupid idea, but you can do it. The larger bike tire bead however will not seat onto a car rim.
I’m happy you’re going with a variable Venturi carb. My British cars have SU carburetters which are variable Venturi.
Loving every bit of this series. And I 'm sure the Saturn will get a decent farewell.
I sure hope so! It's the car the brought me to this channel and it makes me sad they're going to dismantle it for other projects.
The ram air failed because you did not adjust the mixture to compensate. Gotta richen that mixture. But I agree to get the carb you’re going to use first. Once you pick a carb, the ram air can be a focus. Good job. Fun stuff.
I don't mess with carburetors, but isn't the whole point of their venturi system to maintain a constant AFR across different airflows?
Regardless, he's done EFI on these small engines before, and I'd like to see that here at some point.
@@PsRohrbaugh At atmospheric pressures (no artificial pressurization), you’re correct (generally speaking). But if you pressurize the air reaching the carb, via supercharger, turbocharger, ram air, etc), the vacuum signal at the Venturi is actually less. Therefore, with less vacuum signal, it picks up less fuel. So you get a double whammy of more air (due to forced air) as well as less fuel. Lean mixture ensues. Most forced air induction which incorporates carbs compensate for this by applying this extra pressurization to the bowl chamber of the carb which in turn forces more fuel. It’s likely though that jet and needle changes would also be warranted. Carbs are much more fun to tinker with than fuel injection. :-)
@@schzx14 great explanation, thank you!
>carbs are much more fun to tinker with than fuel injection
Hey, to each their own! No problem with that! There are people who love messing with hit-and-miss engines, steam engines, and other things too.
But for me, my brain understands a fuel map significantly better than the black magic of carbs! Especially if you want to casually add on forced induction, nitrous oxide, and similar.
@@PsRohrbaughI love all that stuff too. :-)
Ram air has never worked and is a myth
Tune in next time when Jimbo powers a M1 Abrams tank with a 3.5cc 4 stroke Toyan engine!
Joking aside, I love this channel and the thorough testing- it never ceases to amaze me with what you can get away with yet still be drivable.
Dude, I love the fuel consumption figures. Please don't stop doing those! I want to do an in line hybrid of sorts and that helps me out a lot!
I like the "dare to be different" approach to the carburetor selection. And I hope the Saturn gets another motor. Try to find something really weird that nobody has heard of ever to put in it.
That last 55 mph test was great! The car sounded like it stayed in the power band and kept pulling! I am enjoying this project! Very impressive gains!
We need more episodes of this, I know it's difficult. But really.. We need more
Great job as always and keep it up
I usually finish my Saturday evening watching some carnage in an I Do Cars engine teardown, and then enjoy my morning coffee on Sunday catching up with what Jimbo and the crew have done with lawnmower powered classic French tourers. It's a nice contrast of things that don't work, and things that do even if they shouldn't. Love it!
Heat this week is no joke, stay frosty, gentlemen!
I do cars engine carnage on Saturday nights is always a treat.
Ah, I See You're a Man of Culture As Well... 100%
I do the same, plus I find out what I may or may not be ordering one of by watching Project Farm. Last week, I actually needed a plastic welder. His timing is impeccable.
So I love the straight edge across with fuel cell with the combi square for measuring the fuel level, but to increase the accuracy how about a little gnome in a boat acting as a float holding up a stick, fill the fuel cell up until the end of the stick reaches the same point on the combi square every time
Hmmmm.... I reckon that's not a bad idea. I'll give it a shot.
An old trick I've seen done to help with the fuel's phase change is to heat the fuel before it enters the carburetor, done "quick & cheap" by running the fuel through a length of copper tubing wrapped around a "waste" heat source (heater hose or an under-hood exhaust part) placed in a point along the fuel line's delivery path AFTER the fuel pump or fuel filter.
The pressure from the ram air system also needs to connect to the vent of the float bowl. The jets work on the pressure difference.
Yep, gotta reference the venturi side to the bowl side. Motorcycles have been doing this with carbs since the 90s, and they all have fuel pumps that can exceed the ram-air intake pressure plus the bowl(s) vented to the intake...
@@Xargsify Yes cars and motor cycles do it but maybe a lawn mower didn't. It would explain the ram air thing and also the mixture being effected by other things that may be the same sort of effect. Done right, ram air may get them as much as 2 extra squirrel power.
Thanks Jimbo, I always enjoy checking in on the Cantina!
Glad you enjoy it!
With the "Ram-Air" system a friend built on my '85 S-10 pickup, it drew from the "clean" air seen by the lower front-end air dam. Also: The GM/Bosch TBI system (EFI) was able to compensate for the change in inlet air mass & temperature by constantly monitoring and adjusting the A/F-ratio in accordance to input from the numerous inputs it employed, as well as referencing the programmed fuel mapping "burned" into its PROM (Programmable Read-Only Memory) chip. The result: Avg. 25-mpg@77-mph cruising speed!😁
As always, this was a amazing and enjoyable video. I love the concept of slapping together a car and getting the most out of it. Makes me want to do it sometime.
Note to OP: Re: Cowl Induction. It's well-used in NASCAR as a way to create a "Ram-Air" effect with inlet air to the engine.😉
Thanks for the sunday moneing entertainment jimbo! Coffee and robot cantina is my favorite way to start the day
This is probably my favorite channel on TH-cam. I stumbled upon it at the beginning of the Saturn build. I look forward to every video! Keep up the good work!
Well done to Performance 670, it made your life much easier.
That said, $3.50 a gallon is only about $1 per litre, you get no sympathy from me :-)
It's great to see this quirky French car back on the road.
That is about half the price of gas on a cheap day where I live.
We Americans drive a lot more, our states are the size of most west EU countries and it’s nothing new for someone to drive a few states every couple weeks. I live in Montana and it’s hundreds of miles sometimes for a single school event. Like Paris to Milan, Berlin to Warsaw, Dresden to Vienna for the short trips
When Trump was in office gas was under $2 a gallon, so, it's basically doubled.
@@Steevo69 I'm from Australia, and I understand completely.
Our petrol is more or less the same. It's just tax.
@peterbrown6224 Taxation is theft. Unless I agreed to it they are taking my money, the fruit of my labor, food out of my mouth by government force. I'm done funding wars my children might die in, my family hurt and died for, for people that ungrateful and unworthy. Let them stand and die for their rights as my family has and will on our own ground
Thanks for producing such interesting content. I look forward to Sundays so I can watch your latest efforts. Phil
If you are interested in what fuel costs in Germany. Conversion rate is $1.09 for 1€
Today here in Bavaria/Germany: Gas= 7,82$ Diesel= 7,08$ for 1Gallon
I think twice about taking out my Corvette😊 . Thanks for the conversions to the metric system. Great Video👌👍.
Thanks for the info!
This is the most interesting experimental engineering channel out there imo. It’s crap like this, that I want to work with daily.
Cool, i hadn't seen one of those constant velocity something carbs before, but it immediately reminded me of the legendary 'constant depression' SU carb. Cheers Jimbo!
The air-cooled Volkwagens are known for using CV-style carburetors as well... hence why they typically got such good feul economy from the factory. And at one point, they decided to go with a variant of Bosch's Jetronic EFI system. (Every multi-point EFI on the road pretty-much is...!😉) It worked well... until they discovered American CB-radios were able to generate a strong signal on the same operating frequency as the un-shielded ECM that it employed, resulting in many frustrated VW owners on the roadside wondering "Why the F@$# did it suddenly shut-down!?!"😆
I drive an air cooled VW and I swear I don't think my carburetor is any bigger that the ones you've been using. So now you got me thinking...
$3.5 dollar a gallon is a great deal. Here in the Netherlands we pay €2 euro a liter....😮
5:26 Treee Fiddy! Dat got dam Loch Ness monster..
My wife says she enjoys the fuel economy runs because she gets to see a part of Kansas.
I love this guy. I think everyone who works on engines should watch this as its valuable information.
Making Coffee on Sunday morning and watching the latest episode is part of my mental health program, lol.
The reason VW probably found the exhaust thingy to improve power is because you don't want your fuel to vaporize before getting into the combustion chamber; if possible while still getting good atomisation. It's one of the reasons direct injection is better for fuel efficiency and why it lends itself well to higher compression engines. Latent heat of vaporization is a pretty powerful thing when it comes down to engine performance and even though petrol/gasoline is almost laughably weak at pulling heat from the air around it to do so, it still makes a massive difference for engines. It's also why you can make more power on E85 even though the specific energy of E85 is far lower than petrol/gasoline, the simple fact that ethanol pulls much more heat out of the air to vaporize cools down the combustion chamber enough to provide an actual performance benefit over petrol/gasoline, even though absolutely everything else about E85 should make your car less powerful.
Also ram air intakes need to be very carefully designed to get a decent amount of more air forced into the intake. On modern cars it's easier (and less aerodynamically problematic) to use intake manifold resonaces to achieve a similar amount of extra manifold pressure. Even then you'll be looking at maybe 15% more air which is speed dependent and a nuisance to manage on a car without some sort of system to monitor and adjust the AFR constantly, like say, an EFI system. You could also go the old plane route and add a lever or dial in the interior to let you adjust AFR on the fly, which could make it work. Probably doable somehow with some cables and whatnot going through the firewall and looking like a tripwire inside the car lol.
The carb spacer is also a bad idea on principle alone. You want as short of a distance between the throttle and intake valve as possible to reduce the distance of vacuum between the two to reduce pumping losses. It's why things like ITB's exist. They won't make any more power than a good intake plenum, usually, but they improve throttle response for that reason. There's a reason BMW dumped a whole lot of money and time into developing valvetronic. Having the intake valves be the throttle bodies themselves does a whole lot for throttle response.
about jumped out of my chair w/ excitement when you mentioned you would be giving us at least one last video with the saturn. that little thing is one of the coolest cars on youtube IMO
I used to drive a Renault R10 back when I was in High School (1974-75). I loved the front seats in it and it also got great gas mileage back then. When I came to driving it in the snow it was much better than than rear wheel drive cars of the time. It also had Michelin X radial tires on it. Radial tires were unheard of back then. My dad later replaced the back tires with a set of bias-ply tires. This made the car extremely unstable to drive as the rear of the car wanted to fishtail on every curve. It would be neat if you could find a person who still owned an original R10 and have a race between yours and the original car with the 4-cylinder engine. Thanks for posting these interesting videos.
Thanks! I agree it would make an epic race between the 670 R10 and a stock R10. Sadly the only running R10's that I'm aware of are out of state.
The basic rule of thumb when experimenting is to concentrate on one thing at a time, otherwise it's easy to get lost. You are talented and it's fun to follow the channel. Thank you
The carb on my parent's early 80's Ford LTD Station Wagon was a variable venturi carb, too. From what I remember, my father said it worked really well really liked it. His only complaint was at the time, it wasn't rebuildable. So, when it was time for a rebuild, he ended up having to replace it instead. Really neat design: Good power, good fuel economy, and minimal maintenance.
Ram air is doing exactly what it should do
The "work" you've done on various cars has always looked so fun. If I was your neighbor I'd be over at your garage so often, you'd probably get a restraining order against me. Oh, and I love the shots of those blue skies and green vistas. 😃
In my experience with tuning cars, fuel ratio is only half of the equation. The perfect (stoichiometric) ratio is 14.7:1 at this ratio you get the most efficient burn.
The other half of it is ignition timing you want the timing to be advanced to the point the motor creates the most power as possible then take a degree or so out for safety.
The more power the motor makes the less throttle and fuel you need to supply to get the same results.
Don’t know if you’ll read this or not but hope it gets to you and possibly help :) awesome project
I just love that old car. You still find some of them in Denmark.
Fantastic video as always, i want to see this puppy juiced up and roasting them little donuts its got!
i must say I appreciate the amount of effort you put in. and also the metric conversions, they help me out alot!😊
It may be acceptable in metric, but in America it's said "a lot" as two separate words 😊
@@PsRohrbaugh lol, yes we also do not say aluminium the right way 😜
@@PsRohrbaughgee, wonder why people dislike us Americans. I know you're attempting to be funny, but not everyone gets the humor and immediately places a comment like that into the arrogant American bucket.
For you who cares😅 - I was the owner of an BMW 530d A (e39) it had a 3.0 turbo diesel and ran 5.7ltr/ 100km at around 100km/h (60 miles) the car weight was 1880kg and had a topspeed 247kmh and 0-100 at around 6,7sek.
I kept that engine for a boat but sold it cheap before knowing this channel.
I love this channel and this kind of experimentation! I look forward to each one of these videos, and I recon I ain't the only one. Looks like we are still in Kansas Toto. click click.
Can't wait for that carburator upgrade, your dedication to the science is admirable. It's always easier on paper.
God i love your content. Never thought id be so ecstatic to see a french car with a harbor frieght motor shave 2 seconds on a 0-55 run. Youre doing great and im glad i subscribed
07:12 - Hahaha yeah, I suffered 'Carb Icing' once. Many years a go I had a 1991 VW Polo Classic 1.3 Litre (2 door saloon). I had removed the large circular metal air filter & housing (the design that had a 'Summer/Winter' flap that would allow heat to be directed up through to the air filter housing for warm air to stop the carb feezing in winter), and had installed a home made sponge air filter... ALL WAS FINE in the summer months (could hear the induction roar sound nicely too 😏😉), but, one time during a cold November night driving home from a girlfirends place, the car suddenly coughed and died miles from home. I though "FAAAAK! How am I gonna get home!?" Anyhew, checked under the bonnet, nothing seemed out of place, tried starting the car again and, hey presto! She started! And so, gingerly drove her home expecting a total breakdown... Well, this happened a few times, and after some research I was starting to get a few ideas (fueling? Blockage? Carb Icing?) until one night, torch and screwdriver at hand, I was ready for it. Yup, she died, so I quickly pulled over, popped the bonnet (hood - for you guys lol), unscrewed my DIY air filter, and yup! There it was... FROZEN FUEL in the top of the carb! Hahaha. Being a biker too I felt such a dope as I SHOULD have recognised this from the start! hahaha. So, I swapped back to the original filter & housing for winter, then back to the DIY foam one for Summer. Ohhh what a numpty eh? Hahaha 😉 Sadly, I miss that car 😟, it's one of a few that I SHOULD have kept...
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Intro music!!! I miss the Season 1 intro music. It was short, not too serious, and delivered good vibes.
The intro music in season 1 was great, However we get better audience retention without the music.
Hey Jimbo, back for more like all the others here.
Just a great Sunday vid, thanks man!
👍💪✌
Good video! Recently Uncle Tony did a similar fix on his slant six drag car, he found that routing some exhaust heat to the intake manifold both improved his time and made the engine run smoother.
It's air cooled, so perhaps routing the cooling air?
Plus your get fan assistance for free.
Not surprising - heating the intake runner prevents fuel condensation, particularly if the runner isn't straight. A downdraught carb has less of an issue with it.
This content strokes the best part of my ADD brain. Ive been watching for a long time and always look forward to your posts every week.
I look forward to Sundays for my robot fix….
Man i really like all your vids, they're very technical and illustrative, thanks for taking the time to do what most of us wanted to but can't, appreciate it budd
Garage 54 did a test when they did heat up the fuel to its boiling point and did get almost 2/3 the mileage as with the ambient temp fuel. Sure, the test subject was fuel injected.
Our old moskvitch 412 had also problems when it was below freezing. It also had a pipe connected from the exhaust manifold to the air filter. On summer, many drivers(my Dad also) disconnected the pipe to get better performance and mileage. But in autumn, if you forgot to connect the pipe back, then you where sitting beside the road waiting to the carb to heatsoak a bit and drive forward few km/miles if you did nod had the pipe with you.
I have found your voice double, even the manner of speech is the same! While watching coverage of the California hurricane a weather guy came on named Josh Breslow who works for FOX Now. Pretty amazing. The car is coming along well 👍
Damn this is a hidden gem
Best videos on Sundays!
Hello Dr. Cantina! This is so cute car. Love the driving scene. so pretty!
Thank you for your time and effort, this is quickly becoming my favorite weekly show.
Soon as I saw that carburetor there was a twinkle in my eye. Wait a second I have that carburetor at home.
Your videos have become a sunday tradition for me, keep up the good work!
This is some fascinating testing in the real world very well explained and carried out.
"Nested" intake and exhaust manifolds on inline engines was common from the early 1900's untill fuel injection and multi valve crossflow heads became more mainstream.
Driving around on a 100 degree day in my girlfriends Austin America the engine suddenly died. I got out and opened the hood to find that the carb(constant velocity) was a large block of ice. I chipped some away and as soon as it was mostly thawed I discovered that the heater band that was wrapped around the top had the wire broken off. I thought it only worked to warm it up during cold weather. Apparently that particular carb was very efficient at vaporizing the fuel. No wonder it got a solid 35mpg all of the time. Hooked the wire back and away we went !
LOL, I had the same problem with my Triumph Spitfire every spring.
You sir are living the dream! Love your channel. Hi from Australia 🇦🇺
Idea: go get a pick-n-pull 2 or 4 barrel carburetor and 3D print up an adapter (and riser if you need it). Carbs can be fairly cheap and rebuilding them is cheap, and they will let you ram as much air as you want.
Jimbo, I appreciate you take your time to do these fuel economy tests.
As always, tip of the Hat to the Robot Cantina Team for all your efforts and mad science-ing. 👌🙂👍
P.S: The cold air induction it's always a blessing on ANY engine operating in warm climates.
The whole ram air debacle: YUP, YOU NAILED IT ! It's the same as trying to run a blow thru turbo or supercharged system with a regular carb off an N/A engine.
Im looking forward to seeing how the CVK carb works!
Tuned out for a while because I've been busy in life. But coming back to a RobotCantina video is like coming home. Love the content mate!
Your channel is one reason why I LOVE Sunday mornings!
09:38 - For the 'Ram Air' to work more effectively, you'd have to install some form of fuel injection system setup, driven by a seperate 'Stand alone' ECU with various sensors to monitor and adjust fueling to suit the increasing air flow the faster you drove. It CAN be done, but, it's not cheap as, well, you'd have to buy the gear, install it, and then book the car in for a coupla runs on a Dyno to tune it correctly & effectivly... So... Sadly a little too much for this kind of project. Though yeah, it would be intriguing how that route would go with regards to power & economy. 🤔
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We love the channel and the projects you are working on. Love Love Love the Saturn car wonderful design and execution of the Diesel engine happy some parts will get a second life. Thanks
Another enjoyable and informative video, this channel is my first choice for Sunday mornings. I'm looking forward to seeing how the Renault goes with the new carb. Although totally impractical or just impossible, I'm not a mechanic or engineer so what do I know but I'd love to see an old Weber dual throated carb somehow installed on this engine. Keep up the interesting insane videos.
I had variable venturi carbs (with diaphragms) when I owned a 1980 R80/7 BMW motorcycle. One carb each side (one for each cylinder). Yeah, they were pretty good.
Tuned in a little late, but I certainly can't wait to see what the diesel engine goes into. I really enjoy these videos, and appreciate the work you put it.
I appreciate how you've made the digital speedo easy to read on camera without needing a second camera. I don't think you mentioned how you did this.
Smokey Yunick developed the Hot Vapor Engine back in the 1980's ,he used the waste exhaust heat to preheat the fuel charge so the fuel was fully vaporized before entering the cylinder and got 50+ MPG out of the awful Iron Duke 4 cylinder engine made by General Motors.
Worked on air cooled engines for many years as a Porsche tech up in Dallas.
Almost every carburated motor I worked on had down draft mikuni or weber. Individual runner for each cylinder, not very long runner either.
How about a set of regular mikuni carbs on short manifolds for each cylinder? Those long, bendy manifolds are not helping peak power for sure.
Call me crazy but I always enjoyed syncing up the carbs. 3 barrel down draft weber on each side. Great fun.
On the ram air idea, there is a difference in pressure between the fuel in the float bowl and the air in the intake pipe. If you connect the float bowl vent to the intake, I'll bet the mixture will be more stable. Rotax used to use this trick to their advantage in the 90s to tune their carbureted snowmobiles for higher altitudes. It was called a H.A.C. or high altitude compensator. Early versions used some kind of mechanical vacuum regulator, but later versions used a solenoid to regulate the negative pressure on the float bowl.
Thanks for another fun video y'all! It's quite fascinating watching all the experimenting. Many folk today have absolutely no clue how challenging it can be to tune a carb. Let alone an I4 sportbike. I am so grateful I grew up during the end of the analog days and into the digital days. Being able to tune a carb and yet use a laptop to adjust A/F mixtures is knowledge not too many have.
As usual I enjoyed this vid very much. There's only so many Gen II 426-572 Hemi vids on TH-cam and I'm Hemied out!
For those interested, the Keihin carb, like all carbs, load senses on the principal of there being an inverse relationship between manifold vacuum and Venturi vacuum. Where it is different over conventional carbs is it has a variable Venturi as opposed to the more usual fixed Venturi.
This was another great video. I am looking forward to more on both this and the saturn. I like diesel engines so the saturn really peaks my interest.
Excellent work. Now I look forward to Sundays.
Didn't know the cv carb was for atomisation, well explained! 👏
Thanks Jimbo for another cutting edge tech update delving deeply into the world of D&D (Dittle and Develope). 😂 I wonder if Albert Einstein started this way?
You might want to consider a fuel flow meter, coupled with road speed to yield an instant mpg at whatever steady state speed seems best, just to save huge amounts of time. Of course, then other factors start to weigh heavily, such as air temperature, humidity, tire pressure, wind speed & direction, windows open/shut, and road smoothness & grade.
Those variable venturi carbs have been used on motor cycles since the late 1980's. With the fuel/air mixture going all over the place, exhaust gas temperature would be a nice parameter to know. I don't know how much extra effort/expense these ideas would add, just some thoughts. Combustion temps peak out at about 15:1, so 18:1 may be okay.
Uncle Tony just learned about heating the intake on his slant 6 race car. It was causing stutter while doing 1/4 mile passes. Drove him nuts.
Waking up on a Sunday morning never felt so good 👍
I’ll say it again, that car brings back soooo many memories of oma, and learning so much about a car in general. Was also reminded about the spare tire storage behind front plate while you had the info posted over the front of the car. If I had the cash, I’d buy it when you’re done. Memories 🥰😢 thanks for providing them.
Not sure why, but this is more satisfying to watch than the regular youtube builds where they spend sh*tloads of money to achieve 1000 hp
You have to have the carb vents in the ram air tube to keep the float chamber pressure the same as the ram air.
I love this stuff. Look forward to seeing how these projects go. Reminds me of the days my mates and i spent in sheds with outboards, motorbikes and cars. You probavly already know but with ram air you need to pressure reference your fuel bowls. Tap a hose fitting in there to a plenum shared with the ram air.
the tinyest tires are 125/80R15 who are use on Citroën 2cv...But the best quality (Michelin) tires this size are very expansive (91€ for ONE tire in France).Carb pipes heater are relative similar to the VW on the 2cv flat twin air cooled engine...
The V4 engine on my Honda bike has Keihin carbs, and I love em! I knew exactly what you were after when you introduced it
The discussion about warm air intake reminds me of the "thermac"/thermal air cleaner/exhaust manifold heat shroud on a ton of GM cars from the late 60s and 70s. There was a vacuum modulating thermostat and a vacuum operated solenoid connected to a door on the air cleaner. The air cleaner had a normal under hood or front grille intake, and *also* an intake that connected to a flexible hose and shroud around the exhaust manifold. You can find some excellent 1960s service training videos from Chevy that explain this system in detail - it would blend the air intakes to target a 125°F intake temperature in all conditions.
If I remember from the original EPA documents, this system reduced cold start carbon monoxide by *ninety* percent! That's a huge improvement on top of driveability and efficiency improvements.
Ah! Found it!
th-cam.com/video/FDu0a9X_qBs/w-d-xo.html