silverbullet

I'm thinking about a turbo upgrade, either a k27/6 or a Vitesse Stage 3. Will the stock clutch hold up to this or will I need to upgrade? How much rwhp can the stock one take?
Thanks,
Josh

tconn

You'll need to upgrade the clutch.
Mine started slipping shortly after installation of the Vitesse stg2 kit.

jimbo1111

I had a brand new cup clutch with stock PP. That slipped on a mustang dyno at 350 whp every time. Also felt on the road. My flywheel wasn't in the best of shape. But this gives you a base line as to what it can handle. Actually the week point is not the disk but the PP. It doesn't have sufficient clamping force. Than again one shouldn't make that assumption because prolonged use of the organic material will create much more heat and eventually wear the material out prematurely. I would also suggest to upgrade the friction material if you plan on being in the 400whp range on a everyday basis.

silverbullet

So it should be able to take the 320 or so hp that a k27/6 would put out, if I go that route.

TonyG

Here's a little clarification...

IF...

If you use a Fidenza aluminum flywheel, you can use a stock pressure plate and sport disk (otherwise referred to as a cup disk)... the clutch will hold 450HP at the rear wheels.

The flywheel is the key becuase of the friction surface.

And.. if you get the Fidenza flywheel, you MUST have it balanced before installation.

This is a proven combination that works, and works well.


TonyG

Charlie944

I can attest to needing Fidanza's further balanced. With trigger screw in mine was 2.76 grams at 4.3" radius with point at 263 degrees or about 6 lbs effective mass unbalance at 5800 RPM. WAY too much!! The Findanza uses 1050series carbon steel for the friction surface which is quite hard and wear resistant.

I would also get the ring gear and pressure plate balanced as an assembly as well.
I will be installing a Feramic full-face spring hub disc with a +30% pressure plate and will let you know the results when I get it all broke in if you want.

jimbo1111

What makes the flywheel so special?
When one tracks there car do they use stock friction brake pads with a high quality rotor? I have eaten up brand new stock brake pads in one track day.
When putting the stock disk through the rigger of racing will it survive? Fade is not and issue? Heat and such. Why wouldn't that be addressed first? I'm not implying that your setup can't hold the hp that you say. I'm just curious as to how long it can do it for.
I have a very good friend that is a head tech for BMW. The biggest problem with the new M5 is that the disk can't hold the HP. He has replaced many. This is what happens when one builds a civilized race car.

TonyG

jimbo1111

>>>What makes the flywheel so special?<<<

There is nothing "so special" about any of this..., but the answer is the friction surface.


That setup held up for as long as I owned the car, which included a ton of track days, lots of lead-foot street use, and probably a couple hundred dyno pulls.

TonyG