I know a lot of people (including myself) struggle with which clutch to install. Below is a recap of my clutch buying process and my impressions after the install.


There are definitely some basic criteria that most of us consider.
1. How much power will it hold?
2. How is the pedal effort versus the stock clutch?
3. How smooth/progressive is the engagement?
4. Is it noisy?
5. What does it cost?
6. How long will it last?

Unfortunately the stock "power" slave cylinder adds more factors to consider.
7. Do I have a 996 slave/accumulator?
8. If I have a 997 slave/accumulator, how reliable is it?
9. Can I get rid of the inconsistent engagement of the stock clutch?
10. Should I just do the GT2 slave cylinder conversion?

Below was my requirements for all the criteria.

1. How much power will it hold?
I need it to hold 500-600 wtq.

2. How is the pedal effort versus the stock clutch?
I didn't want a heavy pedal and given past experience, I knew this may be an issue. In the past, more clamping force meant a stronger pressure plate, which directly correlates to a stiffer pedal. I hoped the stock "power" slave cylinder would help reduce the effort of the stronger pressure plate. Multi disk clutches can give you this, but at a high cost and potentially make more noise.

3. How smooth/progressive is the engagement?
I wanted stock, because the stock engagement was already enough of a PITA.

4. Is it noisy?
Again, this is something that can significantly reduce the enjoyment of driving the car, so I wanted something the same as stock.

5. What does it cost?
I was rebuilding my transaxle and doing hose pinning and engine maintenance while the drivetrain was out, so it needed to be reasonable.

6. How long will it last?
Less of a factor as most street setups will last a long time with proper usage.

7. Do I have a 996 slave/accumulator?
No, my car had already been updated to the 997 slave/accumulator.

8. If I have a 997 slave/accumulator, how reliable is it?
From what I can tell, the 997 part appears to be an improvement and this part can be replaced with the transaxle still in the car. Given this, I'm okay with the reliability of this part.

9. Can I get rid of the inconsistent engagement of the stock clutch?
I really wanted to throw the stock "power" slave cylinder out of a window and convert to the GT2 unit, but I needed more clamping force and didn't want a stiff clutch pedal.

10. Should I just do the GT2 slave cylinder conversion?
As stated above, I didn't want a stiff clutch pedal, and hoped that there was a way to take advantage of the stock "power" slave cylinder.

After all my research, I ended up going with a Sachs 764 pressure plate and a stock GT2 disk. After bleeding the stock slave cylinder and getting some break-in miles on the clutch, I'm amazed.

WOW, now I see why Porsche installed the "power" slave cylinder. Even though the Sachs 764 pressure plate is one of the more aggressive (stock style) pressure plates, the pedal effort and engagement are just like stock. The thing that amazed me most was the fact that the vague clutch engagement is completely gone. It feels just like a regular non-power hydraulic clutch. Given this, I would never consider the GT2 slave conversion. I now have consistent pedal engagement with stock pedal effort.

My guess is the vague engagement was caused by the combination of a sprung flywheel and sprung clutch disc. Switching to the un-sprung GT2 clutch disc seems to be the trick.

Assuming this setup will handle my power level (which shouldn't be a problem), I couldn't be happier. If your struggling with the decision, this would definitely be my recommendation.

Even if I had a low mileage stock clutch, I would consider dropping the transaxle (assuming you can do the work) and installing a GT2 disc, just to get the improvement in pedal consistency.

Sorry so long, but I'm very excited about the outcome.

Later, Steve

 

Im really interested to see some reviews on the new hydraulic 'on shaft' clutch/slave that SRM is working with. That was the setup on my old LS1/T56 and I loved it. Good clamping without a lot of extra effort

 

Thanks Steve! Bookmarked for future clutch replacement advice!

 

this discussion is ongoing on rennlist. i have been in seans car and the clutch makes zero noise, was a bit grabby at forst but broke in quickly and became very docile and predictible. it holds a 1000 ft/lbs with no issue. will it last 50,000 miles? i doubt it. for a high hp build i dont think theres a better clutch for the money. if i dodnt already have a erp i would have a tilton. if my erp doesnt hold up to the task ill put a tilton in that simple.

honestly guys these clutches from stock to a triple erp clutchmasters triple are sissy clutches. after 30 yrs of driving tractor trailer rigs with 1000 to 1800 ft/lbs of torque and 13, 15 and 18 speed trans with a clutch that will make your leg shake in atlanta rush hour. if this cutch is to much for you to handle maybe an auto is the proper trans!

 

Lol!

Sent from my iPad using 6SpeedOnline

 

anyone else remember the 2900# act clutches in dsm's that spawned the jokes about having a left leg bigger then the right?

 

And the associated crank walk.

 

I remember driving my buddies for a few days and having to take my shoes off when I got back to driving my car. Took me a few days to learn about the feel of the light clutch engagement of my car, lol