MoTeC, very interesting design!
Because we all know Mark will be pulling some high engine speeds (and we are concerned about his well-being), just curious as to your calculated burst speed of the new flywheel, and flywheel/clutch assembly? These can be very ugly failures especially at high speeds. Analytical calculations or have actual verification tests been conducted? Flywheel material?
Sure you have these bases covered. Would be interesting to know for (for me and) our other readers. Thanks!
We’ve run these 7.25” (forgot to confirm the size in post above) carbon-carbon clutches in our pro drag cars for about 7 years… see below. We turn them in excess of 12,000RPM. Mark will be pressed to see 9k, that will be the absolute RPM limit for his build. The clutch is smaller in diameter than the stock or other aftermarket clutches so the forces on it are less too. Another good thing is the weight is less with the carbon clutch than a stock style clutch so it stores less energy. A stock clutch or one like it coming apart would do far more damage due to the significantly increased mass.
Everything is steel with the exception of the clutch basket and pressure plate. They are titanium. The ring gear is stock. Everything will have very high quality ARP fasteners in it. Installed correctly, and operated correctly, there shouldn’t be any issues.
Lots of pics for those that like images.
We made these clutches. Below are images of a few of the vehicles and clutches that we have run in some pretty serious drag applications. The first car depicted below is a RWD Celica with a 152cuin 4 cyl with a billet head that we made, we also converted the motor from chain to belt drive… along with many other custom parts on the car. The engine is makes about 1600hp, the car has run 6.90s.
This clutch is what I wanted to show you. It is built off of a Tilton center. We made the disk, the stands, and the hat. The only thing really different from Mark’s and the first one shown, that is a 4 disk also, is that the fingers are centrifugally driven to apply the pressure plate and engage the clutch. It acts much like a go cart clutch, but comes in at a much higher RPM. The clutch doesn’t lock up till 8000rpm. A street carbon-carbon clutch and a road race clutch have a diaphragm spring and peddle to engage and dis-engage the clutch. The other difference on the race clutch is the stands are adjustable as the clutch wears. Carbon does not wear much and last longer than other clutch materials. It can also take significantly more slipping, though it does generate a lot of heat when slipped excessively. Good thing is, carbon is already burned up
This was more to show the experience we have with carbon clutches and show something neat relative to the same subject... I hope you find this interesting
Cheers
Here is the ProMod 4cyl… 286 cubic inch, currently producing about 3000hp. It’s half of a BBC with a custom billet 4v head and block. Weighs 1900lbs. We made this clutch too. Shown with 6 driven disk and 7 driving disk... tihs was not enough friction material for our power so we added 3 more disk each and are now 9 driven disk 10 driving disk.