Slacker2223

Hello I am running a 95' miata that is boosted with an early FM cast mani with custom EWG settup. It is mated to a nissan .60/.48 T3 journal bearing turbo to a 2.5 DP, no cat, and 3 inch exhaust. This is running at 10-11 PSI.

Problem:

About a year and a half ago i turbo'd the car and installed the FM lvl 1 Clutch, resurfaced flywheel, and new slave and master cylinder. About 6 months later i was driving and accelerated in 5th and notice that the clutch was slipping. The slipping was getting progressively worse so i turned down it down to 5 psi and it held. The whole time i figured the problem was due to a rear main seal leak because i knew that the engine i was using had been sitting for a while before being installed, and the seal probably cracked.
Well i went ahead and purchased a new clutch disk from FM and a lightweight flywheel and had my mechanic do the work. I received a call from him saying that the seal wasn't leaking, and he had no idea why it was slipping. When i came to pick the car up i asked to see the flywheel and old clutch disk. We then looked closer at where the clutch disk was contacting the flywheel and found that only the center of both the clutch disk and flywheel had contact wear of about an inch.

I took some pictures and will put them up tomorrow at some point

What do you guys think the problem was since i know the flywheel is flat since it was resurfaced? do you think I just got a bad disk? I am going to give FM a call tomorrow and see what they think but just want to know what you guys think could have happened.

TorqueZombie

iTrader: (6)

Was the flywheel resurfaced on a flywheel grinder or a a lathe? If it was a grinder I have no ideas. If it was a lathe my guess is the operator was a tool or the tool was badly operated.

Braineack

iTrader: (62)

the PP should be attached in a star pattern starting at 10ft/lb, then 15ft/lb, then 20ft/lb.

hustler

iTrader: (6)

Bad or good resurface job...been there, done that. I do not like resurfacing clutch parts because the tolerances are so tight.

Slacker2223

i am almost positive that the flywheel is flat. i even used a straight edge on it just to check it. I really think it was the clutch disk

shuiend

iTrader: (24)

Have you called FM to talk to them about it yet?

Slacker2223

I am going to give them a call when I get out of class.

hustler

iTrader: (6)

It could be flat, but enough material was removed that now the center section is contacting the pressure plate or the flywheel. What changed on the clutch disc, did it grow?

miatauser884

iTrader: (11)

I had same problem with ACT Xtreme that came with the engine I bought. Turned out to be the PP. Bought a used matched set from a forum member here, and it works great. Honestly, I would just buy a new PP. I think if they are not installed properly, or whatever. They surface will warp.

I thought it was a bad disc so I re installed the PP with a 6-puck. Guess what....still slipped. Then when I pulled it again I could see that only about 33% of each puck has contact wear on it.

oh, yeah, you will need to resurface flywheel when adding new PP due to what hustler said above.

EDIT: This situation also led me to think I needed a 6-puck instead of an organic disc. I think this was overkill. I have a good disc, but I hate pulling the trans, so 6-puck it is.

Slacker2223

My mechanic checked the thickness of the flywheel after it was resurfaced and it was within spec.

still waiting on my brother to send me the pictures of the clutch disk and flywheel, should be up tonight

hustler

iTrader: (6)

Spec for a stock Miata clutch or spec for an FM clutch?

Slacker2223

I would hope that it doesn't really matter considering when your resurfacing the flywheel your not taking off much. If resurfacing a flywheel by less then a millimeter makes the clutch disk not contact the flywheel then thats kind of pathetic... im sure there are many people running this clutch setup with a stock resurfaced flywheel

shuiend

iTrader: (24)

I used my FM2 with my stock flywheel without resurfacing it or anything. So far I have no slippage up to 240hp.

I really want to know what FM says about it.

Slacker2223

Okay sorry for the wait guys but here are pictures of the clutch disk and flywheel.

falcon

iTrader: (13)

Yeah my FM2 is doing well at 297whp.

Slacker2223

I talked to FM and they sent the pictures to their manufacturer. So we shall see what happens.

k24madness

iTrader: (6)

That disk looks damn good.

By surfacing the flywheel face and not the mounting surface for the PP on the flywheel the same amount the clamping force of the PP has changed. It will act the same as a worn out clutch.

I would have suggested re-installing the old clutch disk and PP with a new flywheel.

falcon

iTrader: (13)

If your machinist knows what he is doing he will remove the dowel pins and grind the flywheel face and the step where the bolt holes are.

I have installed many clutches on old flywheels, some resurfaces, some not... none of them ever slipped.

k24madness

iTrader: (6)

I agree but that does not appear to be the case here. Just look at the grinding stone pattern on the surface of the flywheel. The pressure plate mounting surface does not have the same course pattern.