Best "performance" clutch for a C-900?

[DeLorean]

After many years of service my spec stage 2+ has taken a dump. something broke, sounds like a clutch spring is having a get-together with the pressure plate or flywheel I don't want an overkill clutch, but this car makes a good bit of power, I don't need it slipping at the torque peak. Getting it fast is a plus...

The only thing I have laying around is a 93 9000 spec stage 4! which is too much clutch for the car, it's going to break the transmission unless I am very careful with it... I also have stock clutches, but none of those are going to have the holding capacity. Would love to have to together by Friday, as there is a race this weekend!

[Cark]

Have you considered a mid year (91-93) 9000 turbo/aero clutch? I just put one in my 85 as a preemptive measure for hopefully upping the power a good bit in the near future. The clamping surface is much larger than the stock 900 clutch and many people say that it's good to hold over 300 ft/lb. Clutch feel is great (just like stock, because it is... sort of).

[DeLorean]

I had one of those on the car when it made less power than it does now and it didn't hold.

[Jordan]

I think Luke was running those and with a properly surfaced flywheel and it seemed to hold up.

[squaab99t]

Double post.

[squaab99t]

I had one of those on the car when it made less power than it does now and it didn't hold.

My experience with the 9000 aero clutch has been very good. Started with new Sach (genuine Saab parts) pp and clutch, and resurfaced fw. Hold 300 ft-lbs at the wheels on the Dyno, so little if any tire slip.
Although this was on the Dyno and only a handful of back to back pulls, so it will not see the heat of a road race.
Question, did you start off fresh and what kind of torque and you making?

[DeLorean]

Well, You have me questioning now, it was so long ago what the exact situation was. I have not had the car on a dyno anytime this decade, so I don't know how much power it's making. I guess I can try a standard 93 9000 clutch, and pull off the flywheel and get that machined.

http://www.eeuroparts.com/Parts/58753/C ... -52404401/

Hmm, it is around the same money as a spec stage 2. I wonder which one actually holds more power.

[Jordan]

They aren't cheap, that is for sure. They also require a different flywheel IIRC. I machined a 2.3 9k flywheel with the T5 pattern and it was definitely larger (pressure plate bolt pattern).

[Luke]

I had a lot of slip issues with the standard 9000 turbo pressure plates/clutches, one slipped so bad at Sandblast one year it caught on fire. I went to a clutchnet kevlar disk, that helped but it would still slip some. Next I bought a custom pressure plate from clutchnet. It looked like a standard 9000 sachs pressure plate that they had taken apart and put some sort of new heavier spring packs in. It was pretty expensive but it totally solved the problem after that!

[SwedeSport]

Put the 9k clutch in it, and tune out some of the power. Jefferson is pretty flat.

[Cark]

My 85 uses a stock c900 flywheel that Dave Kennedy did for me. It's just drilled for the 9k bolt pattern, he resurfaced it and lightened it to even out for the larger mass of the 9k clutch. You can drop the 9k flywheel in, but your timing marks will be off by 30 degrees (to some people that matters, to others not so much).

It will be a while before I get the car to power levels where clutch slip will be of worry, but I have no doubt it will hold. Think about how much the 9k guys make on these stock clutches.

[DrewP]

^^ I have that same thing, Dave modified a flywheel to take the '93 9000 Aero clutch about 10 years ago and it's still in there, no slipping issues at ~275 lb-ft at the wheels on a dyno or rallycrossing. Pedal feel is about the same as stock. It's probably got 50k miles on it by now, but has probably only seen 16-18 autocrosses / rallycrosses.

I'm extremely gentle on clutches though.

[IronJoe]

Jeff - I recently swapped out my Spec stage III c900 clutch for a Spec Stage III 9000 Aero clutch. The smaller diameter c900 clutch wasn't holding at 400ish whp, but it barely has any miles on it and would work great on a slightly less extreme setup. If you're interested in it shoot me a PM.