GregBBRD

At some point in time, that clutch was slipping....

Unfortunately, a stock dual disc clutch will not hold anywhere near 400hp, even with brand new discs. The limit is right at 360hp.
(So, when someone tells you they are making 400+ horsepower with a stock dual disc clutch, you can laugh in their face....it's physically impossible.)
However, the pressure plate on the dual disc unit can be disassembled and have the fulcrum for the diaphragm altered.
These will hold about 380hp.(Van has one of these clutches in his stroker....and it "lives" only because he babies the clutch when shifting. He makes sure that the clutch is completely engaged before accelerating.)
For awhile, we had a clutch rebuilder who had stiffer diaphragms. This combined with the change in the fulcrum (above) would hold 400+, however the torque would invariably rip the clutch lining right off of the discs, after a few hard shifts.
(On Joseph Fan's track car, Mark and Joseph put three sets of clutch disc in on one day, with a fresh stroker. When the third set ripped the lining off, the thing got put in the trailer.)

Both Mark Anderson and Joseph finally had to go to a Tilton racing clutch with metallic discs to hold down the torque of their strokers.
These things chatter very badly and are very tough on drive train pieces.

There's a reason why I've spent 20 years searching and attempting to build a better clutch.
I was limited on how much horsepower I could build and still have a streetable 928.
The result is that my latest clutch/flywheel assembly is butter smooth, will hold 800 ftlbs, and appears like it will never wear out.
Incredibly pleased with this!
"High output 928" clutch issues are solved.

Kevin in Atlanta

This is my first foray with installing a twin plate clutch.

New PP, same discs.

I am following the WSM. I have the pressure plate bolted in place and the alignment pins set.

I checked the plates and hubs are point toward the PP.

The gap is way too big or is it?

The clutch plate I can see is sandwiched between the PP and intermediate plate.


Gap seems to big according the WSM

I loosened the allens hoping that would help, but no.

Clutch fork is loose - I kind of expected it be tighter.

So, what did I do wrong?

KB

Kevin in Atlanta

The clutch is fine.

What I did discover is that the stroker kept the 93 upper bell housing and that could be a contributing factor.

I pulled a S3 upper bell housing from my storage unit and fork to ball distance is much better.

Mrmerlin

Kevin any pictures to document what your describing?
Thanks

Kevin in Atlanta

I started an earlier thread entitled Upper bell housing differences. I'll post findings later with pictures.

Kevin in Atlanta

Twin plate clutch.

With GTS bell housing you can see where the ball cup lines up farther away from the ball. Needs some serious effort to get it on and off the ball.

GTS upper bell housing

S3 upper bell housing

Kevin in Atlanta

So, the late model upper bell housing when used with a twin plate clutch preloads your clutch. This then moves engagement higher.

Right?

Mrmerlin

Note in the picture you have the release arm bushing still inside the arm I suggest to dremel the bushing opening a bit
put some DC 111 in it the press it onto the ball the arm will easily slip over the bushing
Well it should

Kevin in Atlanta

Circling back....

The new 'burnt' GTS engine has replaced the stroker engine. I am delighted.

Still has the high clutch engagement with the early upper bell housing. And I would like to address the clutch engagement point.

I have your latest clutch line in hand. GB that is some amazing piece of kit you have there. I have the earlier version on my other stroker and this one puts it to shame.

So, please help me see if I can move the clutch engagement point lower.

How do I reduce the volume to the slave?

TIA

KB