JWT clutch is just too damn good... unfortunately...

Originally Posted by 1slow370

actually the design of the bearing contact on the front of the slave cylinder can actually effect the force applied to the thrust bearing as well. due to lever shaped nature of pressure plate fingers the contact patch actually changes in size throughout the stroke of clutch engagement and different designs of bearing face and finger angle can cause side loads imparted to the clutch as you now need to actuate both the clutch itself and over come the these forces as well. the clutch imparts ZERO force on the thrust bearing, all of the axial pressure applied come from the throwout bearing overcoming friction and the spring force of the clutch in order to actuate it. Zspeed has done a good job with there upgraded (what looks to still be a valeo unit) csc as i'm sure it has no more problem with the o-ring in the base as the metal base probably doesn't distort as much as the plastic one did if there even is an o-ring anymore. But it seems to use the same bearing lock ring and plastic piston that the factory unit uses.

The company i am looking at makes multi-plate clutches, fly wheels, and hydraulic throwout bearings for many many full on drag cars, Midwest america series cars, formula 100 cars, and several other venues of professional racing, the parts are made entirely in the USA, and they don't carry the crazy upmarket prices you find on japanese parts. the factory CSC was like $260 from nissan, the one i'm looking at is full race forged and cnc machined aircraft grade aluminum and is proven to be damn near indestructible.

Originally Posted by 1slow370

so you can confirm that the piston which is in the dead center of the csc and has a rubber seal at the back of it is made out of metal? there is an aluminium base that has a steel sleeve in it, the piston fits in this steel sleeve and is what the hydraulic fluid actually pushes on. In most Valeo CSC's the piston is plastic, then on top of the piston they mount the bearing, a tiny little diaphram spring, and the bearing retainer which has like 8 little fingers that snap through slots on the piston and hold the bearing onto the piston. then the zspeed csc gets glued to the bearing. I've actually posted photo's of the stock assembly dismantled i think they are in this thread somewhere.

Edit: also it's none of the companies you listed, i checked with them but all their hydraulic throwout bearings were way to tall. If they agree to make the parts for us and at a reasonable price i will throw it out there.

As for the distances not off the top of my head i know the factory clutch has just under a half inch of throw, and the setup height of the factory csc is right around 1.8 inch from tranny to pressure plate. I have extra clutch and flywheels sets at my disposal to work from i haven't gotten around to measuring all of them yet.

Originally Posted by 1slow370

valeo makes hundreds of csc's the one in our cars is at the very bottom of there cost line, thats why it's crummy and plastic. They make metal ones, most with the interal plastic piston(which you can't actually see unless you take the mofo all they way apart)and you know how i know the zspeed one is still a valeo? the green boot. all the non-oem valeo csc's have that exact boot on them. The bearing on the front is also a sure giveway as valeo has those custom ordered for them(obviously i'm not talking about the sleeve on the face).

I know my CSC's/HTB's and being that it is a valeo it probably still has their standard .050 fluid entry port on the inside of the hydraulic cylinder liner.