Powerglide factory drum and high RPM
 

Racers,

I have successfully raced a powerglide in many different combinations. Up until now, the highest RPM was about 7800.

Beginning with the Super 10 and also with a fast altered that my Son is building we will be spinning higher RPM's

The Super 10 will be about 580 horse and spin about 8600 at the stripe.

The new altered will be a 930 horse and spin 8600 - 8800 at the stripe.

Are some of you spinning the factory iron drum at that RPM?
__________________
Larry Woodfin, GT Super 10

Re: Powerglide factory drum and high RPM
 

Larry, even if the drum does not blow up, you probably want an aluminum direct drum for class racing. In fact, you probably want to seriously consider a 3 speed automatic.

Re: Powerglide factory drum and high RPM
 

Larry, I have run a lightened steel drum that I do vs a ATI aluminum one and there is .08 difference in my V-6 Camaro that has about 75 -100 more HP and a couple hundred pounds more on you Super 10. I spin both to 9600 on the shift and 9400 through the traps. Remember it is sitting still as long as you are in first gear. when you release the band around it and apply the Hi clutches inside it, it has to spin up in RPM to input speed. I've never had on fail. I do use an aftermarket steel hub because the aluminum ones get eaten up by the clutch plate splines. The weight difference that close to the center of the rotating shaft mass makes very very little difference.
Alan... Larry does not want to be fast. His goal is being consistent and above the 9.99 ET cut off.
You spend a lot less money when you stay away from that magic E.T.

Re: Powerglide factory drum and high RPM
 

Larry
When you consider where his feet are I think you'll come to then right conclusion concernining a cast iron high gear clutch drum.
Bill Baer

Re: Powerglide factory drum and high RPM
 

Larry,

I have a cast iron drum in my powerglide. No issues with rpm to 8800. I have also ran a Coan lightened steel drum in place of the aluminum, There was no ET difference between the Coan and the aluminum drums. Not sure on the stock drum

Re: Powerglide factory drum and high RPM
 

Are you turning down the stock drum, how much?

Re: Powerglide factory drum and high RPM
 

Nit turned down. Milled out in areas the don't do anything good for it.
In short, I delete any metal that is not necessary.

Re: Powerglide factory drum and high RPM
 

I just freshened up an old Comp Elim trans that I did 20 years ago with a lightened stock drum .
Guy sold it to a bracket racer with a SBC that turns 8800 rpm, this thing has probably well over a thousand runs with no problem.
As Adger said , the lightning is done by plunge milling the front face of the drum. ....I've seen many of them done this way , and never saw a problem with one.