I'm in the market for a new driveshaft. Car is 3200 lbs, 800 hp, 8000rpm, t400 transbrake, and driveshaft is 46" in length. Aluminum (4") about 10 lbs lighter than chromoly (3.5"). Anybody pickup any et going to an aluminum driveshaft? Future hp maybe in the 1000 to 1100 range. I've been looking at PST and Inland Empire for aluminum. Any recommendations?
Thanks, Brad

I'd be surprised if anyone would build you one for that combination. My advice, don't do it. I've blown up 2 of them in my dragster, and they are only 10 inches long. And I might have 900hp on a good day. The damage done to everything nearby is not pretty. But this advice is free, so use at your own discretion.

RIP

I sure liked my aluminum one, much easier to work with, but it came apart as I left the line a couple of years ago, went back with a chromoly, didn't notice any difference but its only about a foot long.

I switched to a chromoly from aluminum...7lb difference...no et change...if you dont want it to break get moly

we broke several aluminum shafts in a dirt late model good ones but they just couldn't take it. went back to steel problem solved.

Probably king of lighter is better. In this case I would go stronger and at 7 lbs I would think its anywhere near the ratio of risk vs reward.

My car uses an ~52" long driveshaft. I've had numerous ones over the years with different combinations. 3 1/2" MMC Denny's with a 750 hp bbc. Then a 4" 6061 Dynotech with 1215 hp at 3000 lbs (glide) and now with a th400 I run a Mark Williams 7075 that is glued together. Never had an issue with any of them.

In our customers cars we use either PST or MW.

I would have to go with the durability crowd on this one. I recall WJ breaking an alum. driveshaft at a national meet one time. Unless you're obsessed with alum. a sportsman has little to gain on this item. The relative small circumference makes the centrifugal force a minor factor, say opposed to a 27" bicycle rim/tyre combination.

Thanks guys for your replies. It sounds like for durability, chromoly is the clear winner. I was hoping to shed a little weight but i want a bullit proof driveline. The Mark Williams 7075 is a bit more $$ than I wanted to spend but seems to be the ulitimate piece.

quote:

Originally posted by DOTracer:
Mark Williams 7075 that is glued together.

This..
My Avenger was 1300 hp 1050 Tq. I built the car in 2003 and ran it until I started running the dragster. Still have the driveshaft and will likely put it back in the car with the hemi.

Dave

I've put Mark Williams aluminum drive shafts in cars with well over 3000 hp and had no issues.

I wouldn't use any drive shaft in any race car that didn't come from Mark Williams though. I've seen plenty of off brand junk blown in aluminum and steel.

If your going AL then MW is the right choice and only one IMO. Also note that short DS for dragsters are more prone to beak vs typical door car shafts! MW doesn't recommend them for dragsters but they do make them and the have held up in the ones I know about.

Going to an aluminum (not MW) driveshaft made no difference in the performance, zero gain but it did lighten my wallet. Went back to the MW chromoly shaft for reliability after seeing a few aluminum shafts fail.

Bob

If you're bracket racing just buy the moly shaft. I too have broken an aluminum one in my dragster. Not fun.

I've got a chromoly PST shaft in my TS car and it's been great. Switched from a strange chromoly because it took a lot of weight to balance it and it was wearing the yoke funny and starting to gouge/crack the yoke right on the side where the weight was. The PST took much less weight to balance and has been great. if i were going to something lighter i'd skip Alum and go straight to Carbon Fiber.

Aluminum 3.5 & 4" since I built the car in 96, 2600-2700 lbs. zero problems - started w/ 3.5 @ 870 h.p. switched to Dynotech 4" @ 1084 h.p.

Lighter is not always less rotating weight. If you have bigger diameter drive shaft you need to calculate the different in weight of rotating mass, longer från centerline = heavier. Probably is a 4" aluminum heavier than a 3" chrome moly.