3" aluminum driveshaft

[Jim Caughlin]

I have a 3" alum driveshaft that was built by Inland Empire, I cross the finishline at 9400 RPM and have relatively low HP. Interestingly, I was able to test duplicate steel (13#) and the alum one (10#) on back to back runs, zero performance difference. Actually, I can't say that I saw any noticeable performance improvement from any of the lightweight parts that I incorporated over the years (alum spool, lightened ring gear, gundrilled axles, etc), go figure...

One other note on going to a 3" alum driveshaft, don't forget about resonance / critical speed, it isn't purely a matter of strength. I believe there is a chart on the Mark Williams site that lists length vs RPM for different driveshafts.

Jim Caughlin
SS 6019

[Race Clean]

Originally Posted by Jim Caughlin

One other note on going to a 3" alum driveshaft, don't forget about resonance / critical speed, it isn't purely a matter of strength. I believe there is a chart on the Mark Williams site that lists length vs RPM for different driveshafts.
Jim Caughlin
SS 6019

I think that is the reason right there to use a Aluminum when you are allowed.

[55 Chevy]

I put a M/W 3" aluminum in mine. Very happy with it.

Allan

[Glenn Briglio]

Originally Posted by 55 Chevy

I put a M/W 3" aluminum in mine. Very happy with it.

Allan

M/W doesn't make a 3' aluminum shaft only 3.5

[jmcarter]

Another vote for M/W....only took them a few days from ordering my aluminum shaft to arrival; great technical support when ordering and absolutely no problems.

[Bpozzi]

We run 3” aluminum in all my cars and Fleetpride does them all. They do a great job, and they are local (nationwide)! If something goes wrong, we just drive over and they take care of it vs sending it back and talking to a guy on the phone.

[55 Chevy]

Originally Posted by Glenn Briglio

M/W doesn't make a 3' aluminum shaft only 3.5

Your are absolutely right. It is a 3.5". Sorry my mistake.
And I just pulled it out last week!

[55 Chevy]

Originally Posted by Glenn Briglio

M/W doesn't make a 3' aluminum shaft only 3.5

Your are absolutely right. It is a 3.5". Sorry my mistake.

[Jeff Stout]

Originally Posted by Jim Caughlin

I have a 3" alum driveshaft that was built by Inland Empire, I cross the finishline at 9400 RPM and have relatively low HP. Interestingly, I was able to test duplicate steel (13#) and the alum one (10#) on back to back runs, zero performance difference. Actually, I can't say that I saw any noticeable performance improvement from any of the lightweight parts that I incorporated over the years (alum spool, lightened ring gear, gundrilled axles, etc), go figure...

One other note on going to a 3" alum driveshaft, don't forget about resonance / critical speed, it isn't purely a matter of strength. I believe there is a chart on the Mark Williams site that lists length vs RPM for different driveshafts.

Jim Caughlin
SS 6019

^^^ This. I found nothing in a BBC running high 9s bottom 10s and changed all the same things