I've had a CM FX500. It was abrupt, but I was still able to daily the car in Atlanta traffic. What flywheel are you running? If you run a lightweight flywheel it will shudder a LOT more than if you ran say an AP2 flywheel. The ACT/OEM combo will be at its absolute limit at 480whp depending on torque. It didn't hold for me at 508hp. But what was said above about not using a different disc with the CM flywheel is accurate. The CM pressure plate has an extremely light pedal feel.

 

I am running a stock ap1 flywheel, just resurfaced.

 

Not saying it will solve all your problems, but an AP2 flywheel would make daily driving the car much smoother.

 

This is not true. I have an FX350 with a lightweight flywheel and the feel is stock and absolutely no shudder. 420 rwhp.

 

Your driving style maybe different ie you slip the clutch more but the fact remains. A heavy flywheel has more inertia thus is will shudder less

 

I agree there is more mass thus more inertia. Where is the data to support more inertia means less shudder? I do not slip my clutch either. I had the AP2 flywheel and now the lightweight flywheel and see no shudder and the same pedal force with the FX350. Something else is going on with his clutch mating surfaces.

 

I'm not here to argue with you. This is common knowledge. Do a google search. My comments are from a lot personal experience with this car along with some others. I've ran stock, act, CM, using light and AP2 flywheels and currently on a carbonetic triple disc. Heavy flywheels promote a smoother driving experience while lightweight is more twitchy and demands more precise modulation of clutch and shifting.