Billet drum comparison

Posted By: Sammy

Billet drum comparison - 11/02/13 03:17 PM

I lost a solid .1 from switching from a billet steel A & A drum to a billet aluminum drum
Can this really happen?
No other changes were made and the 727 torqueflite is fresh

Posted By: B3422W5

Re: Billet drum comparison - 11/02/13 06:03 PM

I went from a stock hipo rebuild type 727 to a full roller with aluminum drum and saw nothing.
Others have said they didn't see anything either with such changes.

Posted By: Duner

Re: Billet drum comparison - 11/02/13 06:09 PM

I desperately want to see the difference between a 46RE and a rollerized 727.... I've heard it's as much as 4 full tenths.

Posted By: 80fbody

Re: Billet drum comparison - 11/02/13 07:54 PM

Only built one myself but I wonder if clutch/band materials &/or clearances could have caused the trans to be a little tight? Or maybe the line pressure is off from where it was? Just a little brainstorming.

Posted By: KOS

Re: Billet drum comparison - 11/02/13 08:18 PM

just did the exact same switch and lost 2tenths 2mph........i was wondering the exact same thing.....the alum drum is 6lbs lighter than the billet steel one how in hell can the car slow down???the car 60ft is down .5 and i just did a converter change to rule out the vert will find out tm im tryin to get back out weather permitting.

Posted By: dizuster

Re: Billet drum comparison - 11/02/13 08:48 PM

Band too tight dragging on the drum?

I know we switched from an aluminum to a billet in my Dad's NSS car this summer, and the car slowed down ~.08 from the change.

Aluminum drum should most definitely help, not hurt.

Posted By: Quicktree

Re: Billet drum comparison - 11/02/13 09:16 PM

Quote:

I lost a solid .1 from switching from a billet steel A & A drum to a billet aluminum drum
Can this really happen?
No other changes were made and the 727 torqueflite is fresh

unless you did the swap on the same day same conditions it would be hard to compare.

Posted By: rebel

Re: Billet drum comparison - 11/02/13 09:48 PM

Quote:

Quote:

I lost a solid .1 from switching from a billet steel A & A drum to a billet aluminum drum
Can this really happen?
No other changes were made and the 727 torqueflite is fresh

unless you did the swap on the same day same conditions it would be hard to compare.

a drop of 10 on the barometer for me is almost a drop.08 of e.t. on the same tune.

Posted By: WHITEDART

Re: Billet drum comparison - 11/02/13 10:20 PM

I will lose .1 on a rebuild.. starts coming back after 8 or 10 runs

if the trans is working fine just run it

Posted By: dvw

Re: Billet drum comparison - 11/02/13 10:25 PM

Barring nothing else changed anywhere. The only thing I could possibly think of is loss of coefficient of friction between the K/D band and the drum. A lighter part should never slow the car down. We'll see I have plenty of data with my 10.2 lb A&A steel drum. I'm changing back to aluminum for next year.
Doug

Posted By: Sammy

Re: Billet drum comparison - 11/02/13 11:02 PM

Quote:

Quote:

I lost a solid .1 from switching from a billet steel A & A drum to a billet aluminum drum
Can this really happen?
No other changes were made and the 727 torqueflite is fresh

unless you did the swap on the same day same conditions it would be hard to compare.

This is over the course of the whole racing season. Just never 60 footed where it was and to the 1/8th off by .05 and 2 mph and a full tenth at the big end.
Was hoping for a new best with the good air only to come up short.