Flywheel choice

[patrickt]

Originally Posted by undy

Pat, corrected your misspelling...

Well that was kinda funny. But let's think it through. Seriously, why would you ever need a clutch that had holding power that was significantly greater than the coefficient of adhesion of your tires at their greatest point/condition? (meaning sticky asphalt, pressure at the point you get the most stickiness, etc.) Is there a reason, if greater holding power just tends to create more chatter on the street?

[RICK LAKE]

patrickt Pat Have thought about your question, I want a clutch that doesn't slip when driving or racing. These cars have a small thing on the floor called a GAS pedal and this controls the whole car. If you have chatter your clutch is glazed, burnt, blued or oiled down. I have gone to a street twin, the discs are solid hubs without spring but the release and engagement are smooth. I don't have enought heat cycles or 500 breakin miles on it yet. I want my 600 ft of torque to be hooked to the trans and rearend without slipping. Why run a centerforce with the stupid sliding weights of you are not trying to get the total performance out of the motor? With your soft foot driving why would you every need another clutch?? This one should last a life time. I do have a question how is the high rpm shifting??? Rick l.

[patrickt]

Rick, I still want someone to explain why I would want a clutch that held more than the PEAK point plus a small safety margin. I think Brent is on record here stating that as clutches go up in "hold" ability, so does the chatter on the street.

[undy]

It's more than the clutch's ability to hold a given horsepower/torque. The "stupid sliding weights", are pretty much useless, 'cept when you push in the clutch for a fast 5500 rpm shift and the weights keep the disc firmly pressed to the flywheel. Ask me how I know...

As far as strength goes, I've found a good OEM clutch (not parts store special) to have better clamp than CF's Dual Friction. I've had several run-ins with CF with my small and big block Chebbies.


For the OP, I run the aluminum SFI RAM flywheel on my KC Pond 482 with a single disc RAM 2600lb long style clutch and a sintered iron disc. I'm part of Rick's 600/600 club and have put 8000 miles on the setup with never a slip. Engagement it pretty smooth too. I also run drag radials all the time and have been know to lift a front tire or two

FWIW, it was the KC's clutch of choice when I bought the setup. I do think that if I was to do it now I'd go with one of Rick's dual disc setups. You just can't beat the grip, coupled with the s-m-o-o-t-h engagement. They're 2+ times the cost though.

[patrickt]

Forget Centerforce for the moment (and yes we removed those little gimmicky weights). Is there a benefit to having a clutch that has a hold ability that is greater than the peak point on the graph? And if so, what is it?

[blykins]

I usually aim for the engine's horsepower + 10%. That way if the customer decides that he/she wants to hit it one time at the strip with drag radials or slicks, the clutch will hold.

You're right, as the clutch disc's coefficient of friction goes up, the possibility of clutch chatter goes up as well. However, the weight of a Cobra really helps out here (as does a lower rearend gear ratio) and I can usually match a Cobra up with a sintered iron clutch disc and not have any issues. Where I really have to watch my P's and Q's is when I spec a clutch for something like a Galaxie or Fairlane with a 3.00 gear.

[patrickt]

Originally Posted by blykins

You're right...

Well, that answers that. And I was thinking that I was gonna have to challenge Undy to calculate the slope of the tangent line on that there curve. Bet he was sleeping that day, though.

[flipscobra]

I have a 484 BB FE motor with a Meleod aluminum flywheel that has a bad place on it where the starter won't engage have any of you guys had to replace the flywheel starter ring. Looks like the easest way to replace is pull the motor. What do yall recomend replace starter ring or new flywheel. Its a SPF Cobra