Next to nothing - Best of both worlds - PST Alum DS w/ Chromoly Yoke for add strength

 

Not enough to make a difference.

 

That has nothing to do with strength. Plain and simple it is not suitable for the application if you need to use shaft speeds like that.

When you need to turn fast shaft rpm's, go 2 piece. If made right it will be strong. My two piece has run over 9000rpm ( 200mph+ )and is totally smooth.

 

I have ran a driveline shop for 5 years now. Built shafts for everything. Alum is over priced poo-poo. the weight saved is nothing come-on is every person here racing for mega cash. If weigth is that big of a deal make sure you have the shaft drilled when balancing it, god forbid u add that extra 7oz of weigths. Or appoxy the weights on it deff don't weld them, a good weld is another 2oz. Seriously a strong alum shaft needs diameter for strenght 4''+. In 5 years ive never even seen a cromemoly shaft. However I have built a few carbon fiber shafts for 200k cigar boats. There are only a few things that can bust a shaft, pinion angle, a week tube or weld, joint, and the last thing traction. A 2 peice shaft for high RPMS.hahahahah Id like to see that in a 900hp open wheel modifided. Idk prolly just stick with a 2'' .120'' wall steel shaft that turns 9k all night on a dirt track with 10'' deep pot holes. Just my .02
The best all around shaft I recommend is a 3'' .083 wall BOM non seemed. Seen this shaft move 3600lbs cars into the 7's thats what 1100-1200HP.

 

I just snapped my stock aluminum driveshaft friday night on the streets after a hard shift to 2nd gear.

Snapping the driveshaft on the 1-2 shift, scared the ***** out of me. My torque arm broke as well, my trans tail shaft seal is leaking, the trans tunnel on the car is beat to hell etc. I am so happy I had a driveshaft safety loop. Car would be really messed up if I didnt. This was all on motor too. 400rwhp on full suspension, 40 roll in 1st gear with a moser 12 bolt, 4.11's on a 28" nitto 555r. Thank god I wasnt spraying,









that being said, I am looking into the 3" steel PST shaft with the forged yoke from brutespeed. Its hard to beat for $350

 

What has nothing to do with strength? Harmonic Vibration, and critical speed?

 

And who here is talking about open wheel modified cars ? The majority of the people here have road cars including myself. Or road derived cars used for racing.

If you can build me a steel 1 piece shaft 57" long that can safely turn over 9000rpm....go for it.

And I suspect an open wheel modified whatever that actually is would be much lighter than my road car, and therefore much easier on the drivetrain. And also doubtful they run a very long driveshaft.

 

Not enough to notice. IIRC, the Strange 3" CM weiged in around 18 pounds and my current PST 3.5 ALUM weighs in at 13 pounds. There is a marginal gain but the aluminum runs smoother than the CM in my opinion.

 

True - true all applications are different. Length, weight... Im sure the 2 peice works fine for u. 57" is not to long for a steel shaft, try 72". Was only giving my .02 not trying to offend. It works for u and that's all that matters. So i'll just hush

 

Given the critical speed of a steel based shaft that long is barely 5000rpm. How would you propose to make a steel shaft that can safely turn to 9000+rpm ?

If it is possible, then it could be valuable information for others, and you certainly seem to suggest it isnt a problem ?

Physics does dictate otherwise though ?

 

hmmm... critical speed