Ram 9.5" Clutch Dual Disc Aluminum Flywheel Conversion

[KJL]

Looking for experiences from those who have done this conversion on their ZR1's.

[tnova]

I've installed the 9.5" dual disc clutch with aluminum flywheel in my '91. Very good experience overall with a few recommendations. Unless you're going for the acceleration, I'd go with a steel flywheel instead of aluminum if I did it again. There's a lot of gear lash noise with the aluminum flywheel and the clutch engage is touchy without the inertia of a heavier weight flywheel. Setting the clearances and cutting the drive stud are ripe for error. Just this weekend I talked to Jerry from Jerry's Gaskets and he has worked with Ram to resolve these issues.

[KJL]

I've installed the 9.5" dual disc clutch with aluminum flywheel in my '91. Very good experience overall with a few recommendations. Unless you're going for the acceleration, I'd go with a steel flywheel instead of aluminum if I did it again. There's a lot of gear lash noise with the aluminum flywheel and the clutch engage is touchy without the inertia of a heavier weight flywheel. Setting the clearances and cutting the drive stud are ripe for error. Just this weekend I talked to Jerry from Jerry's Gaskets and he has worked with Ram to resolve these issues.

All the things you note I am also experiencing. The first gear and reverse shudder are most annoying. I did install the shims for the trans counter shaft as recommended by the ZF DOC, which has quieted it down some but the gear buzz and rocks in can sound can be quite loud at certain load and RPM conditions. I love the 4.10 rear and the quick acceleration however. I can tolerate the noise but the shudder needs to get better. I suspect if it doesn't, I will kill the clutch discs in short order. Really need to spin up the RPM to reduce the shudder.

[5ABI VT]

Which disc material did you guys go with ?

[BigIke]

I did the 13lb aluminum flywheel. If I were to do it again, i got with the 18lb steel (i think). With the lightest (cheapest) RAM FW the car will either sound like its rolling rocks, or like a car with a single-mass FW... RACECAR :).

I bought the organic disc. Again, if given a second chance, I think I'd have the ceramic.

Quick question: do you make enough power to warrant the dual-disk clutch?

EDIT: My car does not chatter at all with the single 13lb FW... Dual-disk setups chatter often.

[KJL]

My plan for the car is to go with Marc's 415 600 HP package at some point. Most of the work is done. The car does not have much of that racks in a can sound, I installed a thicker countershaft shim per the ZFDOC. The shudder is getting better but actually may be responsible for a rear transmission seal leak because of excessive slip yoke play. I am getting the yoke sleeved and a new bushing installed into the tail shaft housing. Hopefully that will tighten things up enough to stop the drip. If the shudder does not improve I may swap to the RAM single disc.

[FU]

Quick question: do you make enough power to warrant the dual-disk clutch?


The stock clutch will take 550 RWHP & 500 RWT after that then it's DD RAM , with a 25 or more pound flywheel the RAM DD feels exactly like a stock setup.

[KJL]

Perhaps instead of ditching the DD Ram clutch, all I need is a heavier flywheel. I will check with RAM to see if they make such a flywheel to use with the DD unit.