Rob Roy

Currently finishing up an auto to manual swap on my 88 S4. It has a Stage 1 Murf supercharger ahich I am pretty sure I will be upgrading to a Stage 3. I am at the stage where I need to choose the clutch.

What's the concensus on Spec clutches. I am thinking a Stage 3 or 3+ - is there a great difference in driveability between the two?

As always - many thanks!

Rob Edwards

After Tuomo and Andrew O have weighed in, call Mark Anderson and ask him about his pressure plate mods. Dunno if he can do it to an 87+ single disc PP (I had a DD setup modified for the stroker) but can't hurt to ask...

hans14914

I dont want to stick my neck out too far on this one, but on the Audi side of the world, there has been somewhat of an exodus from Spec products over to South-Bend. Most is just unfounded rumor and trending, but it may be worth calling SouthBend to see if they have anything for you. In my experience, the pricing is historically better with SB as well.

ubercooper

if you drive the car on the street you do NOT want a stage 3, go for the 3+
How much power are you putting down? If it is under 600tq/hp then I would recommend a 2+ (what I currently run on my 550hp hybrid) simply because it is much more street friendly. The stage 3 is extremely jerky and not good for road use.
my .02

ptuomov

My experience with single-disc Spec 3+ has been bad, both in terms of the product and Spec's customer service. The main problem is that, with my stock motor mounts, sliding the clutch when taking off form a parking spot causes the clutch to stutter/shudder/chatter. Yes I had my flywheel surfaced and yes I broke it in with a stock engine without doing any unusual stunts.

http://www.google.com/search?hl=en&q...=&oq=&gs_rfai=

Additionally, my bull**** detector goes off loud when I read their explanations of how the clutch has to "bed" right for umpteen hundred miles. I suspect they say that to get the customers to get used to an unacceptable product and not return it.

In a sense they have succeeded, since I'll only switch the clutch later when I've burned it out (hopefully soon). And since I am already married, I don't care too much looking like an idiot every time I take off, although this may be a concern to some of the single men here.

Jim Morton

+1 on Tuomo's comments.

What I particularly like was the vendor telling me that I did not know how to drive and that was the problem... what BS !

BC

I think everyone should call Mike Simard of Simard Racing to find out about his Flywheel that he makes for 928 engines, with which you can use a 7.25 tilton clutch pack. You need his radial hydraulic throw out bearing, and may need to learn how to drive a bit differently, but he says its not that bad. The flywheel is a work of art. Its beautiful.

Rob Roy

Thanks for the feedback! This is for a car that will see 90+% street driving, but it will be launched hard every once in a while. Murf's Stage 3 is about 510 rwhp, 460 rwtq
So it sounds like some options are:
a) Stock
b) South-Bend?
3) What Mark Anderson has been doing to pressure plates (but might not work with single plate - need to check)
4) Simard's solution (sounds expensive!)

anything else??

Thanks

BC

Ken - its not that bad when you realize a clutch kit for tilton, if you get normal disks, is less than Porsche oem. Also, the flywheel is a one-time deal with replaceable contact ring.

stuartph

Ken

I'll be going with one of mike set ups once i get a few more jobs done on the car

Jim R.

I've been using a kevlar lined disc and heavier pressure plate for the last few years from Dave and Garrity at Motorsports SLC in Utah. So far so good, and you just need to "slip" it a bit in reverse or it will chatter. Taking off in first is fine with no chatter. I did have the guys at Motorsports resurface the flywheel to the finish they specified for the disc material and followed break-in advice.

As a reference, with sticky 295's on the rear, the stock clutch would not hold under WOT in 3rd or 4th gear if you hammered it and got traction. I hate the smell of toasted clutch....burning tires are much better! I have yet to get the kevlar clutch to slip.

There are more choices out there now than when I had to do mine, and having these options for such a low volume application is great.

Good luck with the Murf stage 3, it is an unbelievable bolt on kit!

Jim

mark kibort

how much torque do you have? what clutch do you have?

Im running (racing) with the stock pressure plate enhanced presure, and stock discs with absolutely no issues but I only have 420torque (double disc set up)
With the stock dual disc set up, with 335rwt, there were no issues, but at 420rwt, as soon as I shifted in anger on the track into 3rd, it would slip. I had to wait on shifts to finish a qualifying session, and then spent the evening changing out the pressure plate from Anderson (who had his guy modify it) , that was a dream to drive the next day in the race. that saved the weekend and probably the clutch discs.

oh yeah, 315x30 rear slicks.

mark kibort

I would not know anything about repeated "launches" , but I do some first gear accelerations , out of curves on occasion, in traffic and havent seen any issues, but launches are a differnent animal.

if you go stock, i think the dual disc conversion would be apppropriate, with the enhanced pressure plate. you have 460rwt and thats only 40ft-lbs over what im doing. could be a question, as my enhanced set up worked with 100ftlbs more torque, but would it work with 140ft-lbs more torque. I would imagine it would, especially since you are using it 90% for street. My buddies GTS stroker with 430rwt, has no issues with a stock single disc GTS clutch, but he is no racer of any kind, only DEs occasionally. I drove the car and was amazed of its grip. I guess even though it is heavier, it has more clamping force than the dual disc. or my dual disc pressure plate was tired.
mk

123quattro

I would take a look at these guys. I've used them for a couple clutches and their customer service and products are top notch. Plus, if they don't have what you want they will make it for you.

www.clutchnet.com

Also, clutches do have to be bed in. Usually about 250 miles of city driving will take care of it.

Darklands

Better a slipping clutch than a broken gear!
High modified engines are capable to ruin a 928 gearbox and better change the clutch and not the gear box.