Great Thread!
Well it's time for an update. Since I've put the rebuilt pressure plate back in I have noticed a couple of things. 1) The clutch isn't as hard to press in as the old one was. It feels more like a normal cars clutch. The old pressure pate took a bit more force to get to disengage. Which leads to my next observation. 2) At full rpm gear changes the new diaphragm doesn't grab as hard as the old diaphragm did. Before I could rev my car all the way to red line, do a quick 1st gear to 2nd gear shift, dump the clutch, mash on the throttle, and bark the tires. Now if I get on the throttle to fast I can feel the clutch slip. I can't just stomp on the throttle the instant I release the clutch. I have to let the clutch fully engage THEN I can stand on it. So yesterday I called up the guys that did the pressure plate, and asked them if they had any stiffer diaphragm springs. I was told that they were looking into it, but the problem is there aren't very many pressure plate manufactures in the US any more, and it's getting harder and harder to source diaphragms. So I guess I'm just gonna have to live with what I have for now. No more barking the tires for me till I can source a stiffer spring.
We do 750 miles of "normal daily driving" on each of our drift car clutches before we let them out onto the track because they all slip under hard acceleration until they've been broken in like a good set of brake pads. Just a thought.
Good point Shemp my brotha. Especially since they did hit the clutch faces with a bead blaster. Guess I should take it easy on them. Didn't think they needed getting broken in again since the clutches are about 8 years old. But I guess maybe they do????
Or you've got to get them re-lined due to oil on the clutch pad surfaces. And then bed them in to the flywheel just like brake pads onto rotors.
Yeah, I have a couple of old clutch discs that I may send out to have relined. I'll have them ready to go for when I dig into it again.
Maybe they left out some parts? I never trust those guys. PP is supposed to have centrifigal effect so that as rpm increases presure on plates increase. It is not just the spring. I'm surprised you are slipping with only 80 rwhp. Alternatively did you check the set-up height? If the tolerances are close you will not be able to put enough force on the unit and it will do as you describe.
A friend of mine just experienced a diaphragm failure....he has a 1990 348 (non-FChatter), although the diaphram didn't snap along the outside edge the way Ernie's did, one of the fingers broke away but the cylinder itself is still intact. I will get a few shots and post them up here.
and here it is...can you say KABLAMO !!!!!!!!!!!! -- Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Speeking of, I called the guys at Friction Materials and they said they could make the diaphrams stiffer with heat treatment.
Gonna try..can't source just the spring in Canada Good to know...I'll mention that when I contact them.
Heat treating metal (properly done) will make it stronger. Did they say stronger or stiffer?? Do you really want it stiffer? I am assuming they mean the metal will be stronger and that is always a good thing. Very good sir. Next time I will have one made in the US and sent out here.
Received the new unit today, terrific job by Friction Materials in Longbeach (and once again, thanks to FatBillyBob, Plugzit, and Ernie). The reason I say "terrific job" is because they have to machine this part to spec. -- Image Unavailable, Please Login Image Unavailable, Please Login
My colleague installed the new spring yesterday and took his 348 out for a test run - he says the clutch feels better now than it did when he first got the car
