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Here’s what a clutch looks like getting smoked at about the 50 second spot.

https://youtu.be/zJ-dKHk7Yvc

Jesus! I've never seen a drag race start like that on a dyno before!

gbaker770 wrote: ↑Sat Dec 18, 2021 7:57 am It’s the old “ bolt it together and run it” theory. Then you hear the “ my stage 4 and 3 puck slipped at 10 psi on my 1641”. Proper clutch/flywheel setup rarely happens. Most people check the torque and shim to get the breakaway they want and call it good.
I can tell you a stage 1 and 4 puck holds over 370 whp on the dyno with multiple pulls and will run consistent 6.70’s and 10’s in an 1800+ lb street car on DOT’s if setup correctly.

https://youtu.be/18rNp_oj7m8

Can you detail how to do the proper clutch/flywheel setup? I'm struggling with this at the moment myself.

gbaker770 wrote:It’s the old “ bolt it together and run it” theory. Then you hear the “ my stage 4 and 3 puck slipped at 10 psi on my 1641”. Proper clutch/flywheel setup rarely happens. Most people check the torque and shim to get the breakaway they want and call it good.
I can tell you a stage 1 and 4 puck holds over 370 whp on the dyno with multiple pulls and will run consistent 6.70’s and 10’s in an 1800+ lb street car on DOT’s if setup correctly.

https://youtu.be/18rNp_oj7m8

How was the 4 puck engagement? Sprung or solid center


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Haha my buddy’s first gear was broke in his mendeola. We used his car for the dyno.

Solid Kennedy 4 puck. There is a very big difference between disc makers. I think I tried 3-4 different 4 pucks.
You get use to the 4 puck on the street. I drove the car a couple times a week so it didn’t bother me.

gbaker770 wrote:Solid Kennedy 4 puck. There is a very big difference between disc makers. I think I tried 3-4 different 4 pucks.
You get use to the 4 puck on the street. I drove the car a couple times a week so it didn’t bother me.

Thanks for the info!

Apple tree has a sprung one that I may try, or the solid Kennedy option.

gbaker770 wrote: ↑Sat Dec 18, 2021 7:57 amI can tell you a stage 1 and 4 puck holds over 370 whp on the dyno .... if setup correctly.

2100 lbs + slicks = wheelies. Stage 1, stock disc.

Ol'fogasaurus wrote: ↑Fri Dec 17, 2021 8:16 am The "stepped" style of flywheel, if turned correctly, should have both the PP mounting off-set distance and the disc area both turned to the spec. distances required.
Having the flywheel turned and forgetting to turn the PP mounting area also is not unusual so after turning the off-set distance should be checked just as a precaution.

Most shops will bring their stone to touch the disc surface, then zero the machine. Then they'll grind it down until the surface is perfect. They then go up and grind the clutch surface by the same amount. This is the correct way, right? WRONG!!!! Doing it that way will preserve the error.

The correct way is to grind down the disc surface, then take the clutch surface down until it is 21.0mm above the disc surface. 24mm for a 180mm clutch.

Bruce2 wrote: ↑Sun Dec 19, 2021 10:47 pm

Ol'fogasaurus wrote: ↑Fri Dec 17, 2021 8:16 am The "stepped" style of flywheel, if turned correctly, should have both the PP mounting off-set distance and the disc area both turned to the spec. distances required.
Having the flywheel turned and forgetting to turn the PP mounting area also is not unusual so after turning the off-set distance should be checked just as a precaution.

Most shops will bring their stone to touch the disc surface, then zero the machine. Then they'll grind it down until the surface is perfect. They then go up and grind the clutch surface by the same amount. This is the correct way, right? WRONG!!!! Doing it that way will preserve the error.

The correct way is to grind down the disc surface, then take the clutch surface down until it is 21.0mm above the disc surface. 24mm for a 180mm clutch.

I agree, the two surfaces have to be "relevant? to each other.

I haven't been in a machine shop when grinding a flywheel was being done so I don't know which surface is done first but correcting the clutch disc surface, I would think (from seeing some very dam(n)aged flywheels before machining), that surface has to/would be the primary surface of concern and that the mounting surface for the PP is dimensional to that surface.

Your input was good... thanks!

Lee

How do you deal with different thickness on the disk? I have 3 disks at home and each of them are different.

Shims

A "just for talking" opinion:

With the kind of "shock loads" and other things that can be applied to a flywheel/clutch setup I am not sure about the use of shims. Shims/washers can be "slippery" plus the fasteners usually used are fully threaded so they not usually designed take "shear loads" as well as bolts designed for shear loading .

Lee

There is no shear loading on the bolts. The pressure plate is held from rotating by the friction between it and the flywheel. The only time the bolts will be in shear is if the pressure plate can turn. If that happens, the bolts were loose.