S3 E40. We road test the 670 Predator Renault with the new exhaust and Comet 94C clutch 

Point the exhaust straight out the back to take advantage of that sweet 2.5% horsepower boost from the exhaust thrust.

The tension of a battery going dead, the clutch and its iffy shifting, I was on the edge of my chair the entire episode 🎉

I feel like peak Robot Cantina would be putting a supercharged predator engine in a AC Cobra Kit car for performance testing.

Love your content Jim. Lots of fun. CVT weights and spring and or ramp needs to be adjusted to match the power curve of the engine. There should be some old sled racing guys around to help. It is a bit of black magic!

This channel is like an adults version, of Saturday morning cartoons. Pure enjoyment. Thanks Jimbo!

The CVT seems to be performing normally, although some tuning could still get you some performance. At WOT, it should hit top RPM and stay there until you lift your foot. You shouldn't be dropping rpm as the CVT upshifts.

having to change so many things at once can make it difficult to figure out just what needs to be changed to get back to where you were. As always the journey is entertaining, thanks for taking us along for the ride.

So glad it's Sunday again and Jimbo is back with another video! Thanks man 👍💪✌

The thicker, more rigid belt saps power compared to the old setup. I had the same experience when I changed from a normal to a reinforced belt on my scooter.

2:12-Well Jimbo, you just proved unhirable as an engineer for many auto manufacturers by actually taking into consideration the ease of removal of your designs. How disappointing. 🤣🤣

Can't wait to see the bigger carb on the car now that the CVT is working!

Keep these coming, this has become my sunday morning ritual!

Love watching these projects come to life! I'm a snowmobile guy at heart, would love to see what a 2 stroke snowmobile engine could do in an application like this!

Yay! A cup of Joe and Robot Cantina! What could be better on a Sunday morning? 😊👍🏼

I was so excited for this one. Maybe once you change to dual carbs and those new belts soften a bit you'll get better results.

As much as the episodes themselves, I've really come to enjoy listening to the music track at the end... You caught me off guard with the 'DOH!' 👍😉🤣🤣🤣 😎🇬🇧

I really like how you walk through the variables of the process

I appreciate that you want the pipes to be smooth and uniform diameter so people won't criticize you and say your work is ugly, I totally understand wanting it to look good for the video. Those primaries could probably be quite a bit smaller without costing much power if any or could have wrinkles, dents or spots where they are smaller diameter to make your equal lengths. Engine Masters with David Frieburger did a test on a Mopar 440 where they purposefully crushed down the primaries on the headers a bunch, equal and unequally, beginning with either 1-7/8 or 2" primaries, it had basically zero effect on power, that engine has 8 cylinders that are each 900cc, 7.2L ÷ 8, so in all likelihood you could have probably made that exhaust less pretty to get your equal length and it probably wouldn't have effected anything much. Who knows what primary lenght, what primary diameter and what point you place the Y pipe would produce the optimum performance, perhaps the combination that produces that absolute highest peak power might produce less average power or power under the peak than a different set up which could end up producing better acceleration than an exhaust that generates the highest peak number? I realize that is not something that you could really get in there and find out with no access to a dyno and not unlimited time and money. It's cool to think about though. Love your stuff, I watch every week. I was in Brazil from August to Nov and your show was a nice treat every Sunday morning so I could hear someone speaking English and messing with engines to keep me entertained, thank you 😊

Sundays are so sweet with Robot Cantina in the feed.

Great video as always Jimbo. :) Your editing just keeps getting better and better. The pacing of this video was a bit slower than some of the others and I actually quite liked it. The modern YT pacing is really rushed, whereas this video felt a lot more like a natural conversation chatting with you while sitting in the passenger seat. I especially like that you included a little bit more lead in and lead out with each scene, giving us a chance to walk along with you to the car, around to the back, climbing into the driver's seat, and so on. It feels a lot more like actually being there, rather than an action-packed montage. Both styles are fine and you do both well, but the more natural, casual pacing just seems more appropriate for this kind of a project. I watch every Sunday and I look forward to next week. :)

This is silly, I have more fun watching this channel then any other, and I normally don't even look at a car unless it has massive power....lol

Awwwwe yeah! Coffee and Cantina time 😎 hope you had a good week, Jimbo! Cant wait to see what you got up to.

I have a Daff 750 which is a very similar style car. “Daffodil” invented the independent centrifugal clutch drive. Eventually it became Volvo. Mine has two centrifugal clutches, one for each rear tire. They were ahead of their time and out performed the drive systems of the day in all weather conditions, especially since most roads were dirt. The independent drive would allow each clutch to spin at different rates for traction. However, they were not popular because folks were used to shifting gears and didn’t like the automatic type transmission. It has a 2 cylinder motor with horizontal cylinders. There really is nothing to it. You can drop any motor in it and bolt it to the four bolt drive shaft or run a jack shaft and you’re off to the races. The master brake cylinder isn’t much more than what comes on a scooter😂 I wish I was closer, I’d give it to you. The body is shot, but the drive system is good😊

Appreciate your Videos. I like the way you test every change to see what effect it has on the cars performance. Looking forward to more tweaking on the Renault and Diesel Insight Videos.

Someone get this man an exhaust bender, he can literally do everything else.

I like the grader just driving down the road like it's no big deal 🤣

Hey, the lone wolf 9000 made an appearance lol

I noticed that the old speedometer on this car goes to 100. Seems like a good final goal for the project!

May be worth to give 2nd gear a try since the overdrive capabilities of the new cvt. May be able to run to 50 in second now.

Sunday mornings with Jimbo are great!

You should get some cheap sawdust/mdf panels or thin metal sheets to cover the underside of the car as much as possible and cover up the front grille from behind (could just use cardboard and tape for that). Cars didn't really have flat floors until the early 2000's and they make a massive difference to lift and drag especially. With how little power that engine makes combined with how much every accessory running off that engine saps the power it could make a sizeable difference for pretty cheap. Just leave a bit of an opening at the back to pull air in to cool the engine and leave the top open to exhaust it back out so it doesn't build pressure in the engine bay. Also, if you can, 3D print a long-ish (150-200mm) trumpet for the big carb when you eventually get back to it. You can print a mounting point slightly below the top of the trumpet and keep a bit of clearance out to the sides of the top of the trumpet to fit an airbox thingy so you can keep the filter while benefitting slightly from intake resonances. Consider adding some vents to the back of the interior as well, or just opening the rear windows very slightly; would help pull air back out the car to keep yourself cooler in that old cabin.

OK, the "D'oh!" at the end there made me grin.

I love this little Renault project. I certainly don't find the videos "meh."

I love that old Renault.

Jimbo you would be my favorite neighbor that I would share my top shelf bourbon with and tinker in the garage!

Your videos make me beyond happy.

Hi Jimbo, Just so you know. Equal length headers only work on a two cylinder engine, when the firing interval between the cylinders is 360deg. Since this is a V-engine. One exhaust tube should be a bit longer than the other. What should be the same is the intervals when the exhaust pulses reach the collector. Nevertheless great content as always. A lot of the stuff you test is applicable to my project car. It's a Fiat 126 from 1973 with a 2cyl, 650cc engine in the back.

This is the quirkiest of all car channels and i cant get enough.

I need to start going to bed so I can get up to watch your videos on Sunday morning instead of staying up all night. :D

Am I the only one who noticed the boxer engine sound with those unequal length headers? I was super excited for the engine sound when you mentioned that and it did not disappoint 😎

He should have a bumper sticker, my other car is powered by a cement mixer! Lol

This testing takes me back to my days as a test engineer. Keep up the good content 👌

He sure gets you invested.

The CVT should idealy keep the engine in the same rpm (rpm where the engine has the most power)all the time while excelerating

I think the newer drive belt setup is doing pretty good considering the rotational mass of it

Sweet!!

Softer spring might help the cvt to shift earlier keeping the engine in lower rpm for more torque.

Thanks for another banger of a video Jimbo! Have an awesome week!

MUCH LOVE FROM INDIANA!!! Keep up the good work!😁

Enjoy these. Feels like what ill do when I'm retired. Keep it up!

This car performs allmost like new from factory with oem engine😂. Great work

🎉

Your videos are the best way to start a Sunday morning thanks for sharing

Thanks for another great video!

Brilliant,really enjoyed,thanks for the video.😊

Thanks again for a great video.

Thanks again, looking for the next one

Awesome work Jimbo, thanks for the video !

I see the next project is sitting out back. A twin predator powered bus. 🤣🤣

Glad to see the project getting back out of repair mode and back into testing things

Love watching buddy makes my weekend thanks for sharing Thank you to all veterans for your service

Regarding the CVT, have you tried starting in a lower gear to force the RPM higher to advance the CVT faster? (And I realize this may be a dumb question. I just don't know, so I'm asking. LOL)

Thanks for the weekly fix!

Another complete Sunday with the latest RC video! Winning!

Ain't even watched the video yet but I'll just go ahead and say it was awesome because I already know it will be!

awesome project

This is really interesting and your incremental approach is great. Swapping back and forth between the Renault and the Honda is also very enjoyable seeing the progress on both. 😊

I'd love to see Robot cantina get their hands on a kei van and swap it with an engine making it top out at 120 mph.

Looks beautiful installed in car.

lots of crazy work into this

Hey Jimbo just found your channel! Love the content!! Saw the Arrow H picture in the video. Greetings from Nashville KS 👍

Your videos are awesome thanks alot Sir

Anyone else chanting "come on baby" in their head while watching the speed and timer climb?

Thanks!

And yet another riveting episode thank you for dragging us along with the ups and downs of experiences of seeing what can be done maybe next time you should leave us at the shop the Renault would be lighter without 140,000+ in the car!

I loved the missile launch system panel to start the engine

Another fantastic episode mr jim

Sounds awesome ❤❤❤❤

Fascinating!

Why did it take me so long to see that “BFE” sticker? Love it!!!!

ANOTHER great show , i'm a V8 peddler , but love watching this quirky stuff . if i tried to do that , i would get a fine

Space shuttle command to launchpad over... bzzt, launchapd clear and the air filter is on place. Roger, starting the countdown sequence now !

Thanks Jimbo!

thanks 4 the vid

Good content thanks for another fact filled video🤗😎🤗😎

Boy that weight difference really demonstrated how a change can alter the overall performance 0-50 and 0-55. Cant wait to see this thing get down with the fine tuning and larger carb later on. Thats honestly bound to be a car capable of very respectable acceleration given its age.

To get nicely matched primary pipe lengths, try using a collector box rather than a "Y" branch. The pipe ends can then poke into the box independently of each other, the ends don't need to be level with each other and you don't have to use strange convolutions to match the primary length. The outlet to atmosphere can then leave on any side of the box that suits. Simplifies things no end.

This thing is running way smoother now. Looking forward to seeing this thing with bigger carbs.

Lol! It just never ends, hunh? Lolol! Thanks for sticking it out, though. Once you get this one and the Saturn squared away, I suggest doing something fun with a Plymouth Prowler! In the meantime though, enjoying this journey with you. Frustrating, but fun! 😊

I love the fact that we can hear the engine over the exhaust finally. It sounds like it is starved for fuel (As you mentioned Jimbo). Also these have no torque at low RPM. I realize there is transition time to shift but I think you are currently at a point where a start in 2nd would work better to get momentum as the engine RPM would be more in the proper range for peak torque despite the time loss of the extra shift transition time. Best part is we get to see what you did in another week and live vicariously through Robot Cantina!

Hey Jimbo. Love your work 👍

need to put a go pro pointed on the CTV when driving

Next big upgrade has got to be the 999cc big block and if that goes well maybe a fun road trip 👍

play with the cvt weights, aloot can be done with washers an weights, pipes sounds damn good to thats an awesome looking exhaust Jimbo !

man just listening to the vid i couldn't tell the engine was over reving at all, but adding weights and bringing the rpm down made a huge difference!

Still need a downdraft carb and tune the extractors. Tuning the CVT was first on my list. Wen tuning the extractors, make the volume of each pipe, the same as the volume, or twice the volume of one cylinder.

Comet 104 clutches are the most common clutch in a snowmobile. Good past 100 HP. One of those would have given you growing room lol!

another interesting vid.

Olov Aaen clutch tuning manual will be a big help to you.

Doh!