A question of clutches.......

[ShadowLands]

So there's this "sealed crate motor" class coming up next season and I'm curious to know the opinions of the stick-shift crowd on this one. Brief rundown: engine is the Ford 5.0 "Coyote" engine sealed from FRPP. No tuning is allowed. Every racer will have the "spec tune" loaded into the PCM during tech at each race to ensure everyone has the same tune. Should be good for around 430 hp and 400-410 ft lbs of torque at the crank. Minimum weight is 3200 lbs. Maximum tire size is 28x10.5. Unfortunately, the transmission choices echo some strange, long-standing "street car" persona at NMRA so we have to run some form of Tremec transmission. Looks like the gearbox of choice will be the G-Force prepped T5. You can run this combination in any Ford body from 1954 to current.

Along with the transmission dogma we're also stuck with another long-standing tradition in the NMRA......a diaphragm clutch. Below is how the clutch rule is written in the preliminary rules (although I don't expect it to change one bit in the final rules):

Standard Ford OEM factory-replacement-style single disc diaphragm clutch required. Steel or aluminum pressure plate a minimum of 10.0-inch in diameter is required. Adjustable pressure plates, or long-style pressure plates are prohibited.

The factory Coyote cars come with an 11" clutch. Given that we are dealing with less than 450 ft lbs of torque would you forgo the factory clutch size and run a smaller diameter setup? A 10" perhaps? Also, what base pressure would you shoot for?

[Jeff Lee]

will they allow a sindered iron disk?

[ShadowLands]

Yes, any material. Just cannot be smaller than 10" diameter.

By the way....this will be a leaf spring car with Calvert stuff underneath the rear and a 28x9 tire. Just don't think it needs a 10.5" slick at this power level.

[Jeff Lee]

I started to write it all out but decided not to tell any of your competitors that may be lurking...check your PM

[Jeff Lee]

I see you don't allow PM's. Email
JeffLeeAzRealty@gmail.com

[Run to Rund]

You just need a shop savvy in diaphragms, like South Bend Clutch, to work up a pressure plate with fairly low pressure to work with the same #5135 sintered iron disk that the adjustable clutches use. In my car 1100 with a Borg and Beck wasn't enough, 1365 lb. with double rollers was plenty. I haven't tried anything in between yet, as the latter setup is working well.

[ShadowLands]

Originally Posted by Jeff Lee

I see you don't allow PM's. Email
JeffLeeAzRealty@gmail.com

Oops. Too many boxes checked on the PM stuff. It is fixed now but I'll shoot you an email as well.

Thanks!