Clutch disks...

Hey everyone,

We're changing over to a 10.7" clutch for next season in our TAFC. Just was curious what everyone thought about clutch disk size. I'm told you can run the 10.7" disks cut down to 10.5". Anyone doing this and finding it better or worse than the 10.7" disks?

Any info and opinions are appreciated!

Just for info our deal is a TAFC, 511cu in BAE, Crower 10.7" clutch, PSI D.

Thanks!

 

clutch size

a smaller diamiter disc gives you more room for tuning on the counter weights. some big dogs are running as small as 9" dia. I dont think the clutch would know or care if the disc was a 10.7 cut down to 10.5 or was a 10.5 originally. more important is the hardness

 

Changing the the diameter of the disks is a big move in the top fuel ranks and so on. The reason being that surface area is a huge factor in the way the disk wears and performs. A smaller outside diameter typically makes the disk less aggressive and wear more. The idea came from the guys running six disks in the fuel ranks when they were forced to cut the nitro percentage back. It takes a lot of power to get through all the surface area of a six disk clutch so we trimmed the o.d. back so it acted like a " 5 1/2 " set up. Another interesting fact is if you leave the standard O.D. of the disk and trim the Inner diameter the disk becomes extremely aggressive as the coefficient friction goes up. Best of luck!

 

we are running a 8inch titan clutch in the tafc.

 

It can be done and has been done regularly in cars that fly, including a wiley old Calgarian whose car has been in the 50's often.. The honest difference between a true 10.7" disc and a 10.5" is 1.1% in your overall torque capacity at the hit. As someone mentioned, it won't notice a huge difference there. The effect is slightly exponential, so the higher the given plate load, the greater the effect, which will give you a little more room counterweight wise, but as I said, it is a small percentage. Now, having said that, sometimes that small percentage means making it or shaking, but you honestly won't lose much of anything running a 10.5" disc. Just make sure the I.D. is cut to match at least the I.D. of the heat shields and floaters.

 

clutch discs

Nathan, 10.5 disc is all we used for several years in our TA/FC, got a bunch of used discs from fuel cars with 1.750x 10 splines, had Lenco make an input shaft, built a candle stick for the t/o brgn, never noticed any diff. Still using the discs in our NFC
Keith Clark

 

Great info all!

Cool. I made the original post just over two years ago when we were switching combinations, now we're switching combinations again - going nitro funny car racing. Anyone want to buy a TAFC turn key? 65k - any takers?

 

Any one want the ULTIMATE Nostalgia Nitro clutch? Boninfante 9-stand, 10.5" all Ti never used with a bunch of NEW Ace disc and floaters??? Thanks, Tim 616-260-4064