Re: steel or aluminum driveshaft?
 

Mark...go to the Mark Williams website and look up "critical speed"..... while a performance improvement is nice you need to spec out your driveshaft based on your trap rpm you achieve.....the diameter and material type will be decided once you have your shaft length and trap rpm....


as an example for my stocker build I needed a shaft 54" long and needed to handle at least 7000 rpm and since it had to be steel I required a 3.5" chromoly shaft.....while aluminum can give you a higher critical speed it is less durable.....


D L Rambo.....Stk 1300

Re: steel or aluminum driveshaft?
 

If any gains are to be had you should see it by using all the parts.


You have met the required parameters.... rpm, 4cyl power, ect. all those "should" improve your performance, results speak louder than theory though

Re: steel or aluminum driveshaft?
 

Carbo fiber. Don't know about improvements in performance, but takes the shock out of the driveline, and is way safer. Ran a 6.20 rear gear for over 100 passes at 3040# with a 5 speed.

Re: steel or aluminum driveshaft?
 

I agree that carbon fiber is probably better but not legal in SS.

Re: steel or aluminum driveshaft?
 

I see a few comments about durability concerns with aluminum. Maybe I have been lucky but I have ran a Dynatec aluminum shaft for several season in my car. 3350lbs run 1.11 60' and have not had any issues at all. I do agree that the performance gains were minimal at best compared to a chromemoly shaft.

Re: steel or aluminum driveshaft?
 

Swapped the stock 3" driveshaft in my 3880 lb. Chevelle back in '99 for a 3 1/2" MMC driveshaft from Denny's, worth .04 in the 1/4. Put thousands of passes on that driveshaft without issue or failure and it's still in the car today. Ran a best of 1.28 60 foot with it and well into the 9's.
http://i381.photobucket.com/albums/o...n6-15-08-1.jpg


Further, my 3144 lb. MPR Firebird has a 4" aluminum driveshaft and has been 1,17 60 foot and well into the 8's also without issue or failure.

Re: steel or aluminum driveshaft?
 

I really think it depends on the application. I swapped a steel for an aluminum driveshaft at the track for a back-to-back comparison and gained absolutely nothing. The added bummer was that they were checking driveshafts at that very race. They wound up banning them at the end of that year in Stock Eliminator, unless they were OEM for the particular car.

Re: steel or aluminum driveshaft?
 

plastic

Re: steel or aluminum driveshaft?
 

I changed from a Strange light weight steel spool to aluminum, lightened ring gear, and aluminum driveshaft. My car is evidently dumb, because I saw zero. Well, actually, I lost first round at the last race I ran at Memphis when it cleaned the right side splines out of the spool on the starting line. About got the tree.

Still have the driveshaft. Steel spool stays in it now, and I don't spend money on lightened ring gears.

Re: steel or aluminum driveshaft?
 

I was told a story about Kip Martin (RIP) and his Super Stock Mustang.
Kip ran an Aluminum drive shaft which broke at a race.
I was told he found a steel replacement and his car slowed down a few 10th's and MPH.
As soon as he replaced the steel unit with an Aluminum one, he gained back his ET and MPH.

Also, as I understand, Stephen Johnson replaced his steel unit with Aluminum and also picked up ET and MPH on his Fairline.