Clutch pedal much lighter at high RPM?
 

New ACT ProLite (10lb) flywheel, Rotary Performance organic clutch, and Rotary Performance black pressure plate.

Why would clutch pedal pressure be DRAMATICALLY lighter at higher RPM (6000+) than lower RPM (3000)?

Operation and clamping force is fine, but during spirited driving, the clutch pedal is a limp noodle - and at lower RPM the pressure plate is already lighter than stock despite my strong request for much greater feel and weight compared to stock.

Any thoughts? This isn't a center force clutch, and that should clamp harder, not softer, at RPM, not that their clamping force is related to pedal pressure.

I'm lost, but this sucks.

:dunno:

question is, why would u get anything other than the few big names like exedy?

let me guess ... cuz this one is cheaper?or is it because u think u will get more power like that?

Charles, Thank you for the diagnosis. I will take the appropriate action and see what they can do to rectify the situation.

nycgps, Cost was not a factor in my decision. I understand that Exedy makes the stock RX-8 clutch pack, which I hate. No feel. Too light. So I avoided other products from them. I had heard that CenterForce has had quality control issues. I took a shot based on other feedback. Until Charles' advice, above, I suspected installation issues. Now I have another avenue to pursue.

And, please, don't lump everyone into the group of idiots that seems to believe that everything from clear corners to v-tech stickers add horsepower. Besides, horsepower doesn't make you faster, driver skill makes you faster.

just because the clutch "feels" heavier doesn't mean its better. you are just adding more stress to the drive train for no reason. i had act clutch before and i removed it, simply because there is no point, each to their own i guess

in a sense, power does make you faster. its harder to control an overpowered car than under powered.

and I'm fairly sure a fully modded civic will beat a stock civic. even when its driven by the same person, the person will be faster because of the horsepower.

Charles,

Trying to understand your suggested resolution to my issue.

If the pressure plate is too close to the flywheel, I can see that the fingers wouldn't crown as high as they should and the throw-out bearing would need to pass deeper into the pressure plate to effect the same throw distance. It seems reasonable that after a certain point in the throw, the lever action would get all wonky and all kinds of funny symptoms may result.

What I can't quite picture is how this changes with RPM. I would expect that strange behavior would exist even with then engine off.

If it matters, I prefer my clutch action high, rarely pushing the pedal past the dead pedal. The system is well-bled, the clutch slave has been replaced as part of a diagnostic effort, and the pedal adjuster does have some free play (so I'm not hanging on the pressure plate).

If you have the time and inclination, I'd love your explanation. I'd prefer to know a little more of what I'm talking about when I try to fix the problem.

Respectfully and appreciatively...

Folks,

If this is still an issue, I used about 0.060" of shim (looks a lot like a washer) between the flywheel and pressure plate. I have an ACT flywheel and an Exedy Stage 1 clutch. The fingers are crowned significantly more and pedal is not as scary at high RPM. I only have a week on this configuration, but the pedal is what I expect (a little heavier) and while it gets a tad lighter towards the end of the travel, it is probably no lighter than the old clutch. As the clutch beds, and the stupid spring thing in the middle settles, I expect things to be just about perfect.

I can share that the second time you take the transmission out is a lot easier than the first time. I added mine with the trans back a few inches, a long extension through the starter hole, and someone turning the engine (ratchet on the alternator bolt). The pattern is: turn bolt, turn engine to the 3rd bolt, turn bolt, turn engine to the second bolt, repeat until you have touched all 6 bolts. This pattern will let you loosen and tighten the pressure plate evenly.

In theory, with patience and a little luck, you could do this through the starter hole IF you had a box end crow foot wrench like these.


And someone to turn the motor. I did not have one, and could not find one to buy. I also could not wait because I screwed it up so bad trying to do it without the wrench that I could not drive the car.

Thanks to Charles at BHR (who I bought the stuff from). He found a solution, tested it, and got it out to me pretty darn quick.

Mike

Would it possibly be easier to adjust the clutch slave cylinder?

^^ what he said. basically it is the geometry of the tabs that the release bearing pushes against. If they go past the middle, they start to release themselves through centrifugal force.