steel or aluminum driveshaft? - Page 2

magnumv8 · 12-03-2014, 02:43 PM

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

Bill Diehl · 12-03-2014, 03:09 PM

Quote:

Originally Posted by Jim Caughlin

Same issue with lightweight rearend parts, gundrilled axles, alum spool, lightened ring gear, no noticable improvement. On the other hand, lighter weight flywheel and clutch made a huge difference. In my case, this is a 4 cyl motor that crosses the finish line at 9200.

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

randy wilson · 12-04-2014, 07:35 PM

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.

Jim Caughlin · 12-04-2014, 08:44 PM

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

Nathan Stinson · 12-05-2014, 11:01 AM

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.

1320racer · 12-07-2014, 09:16 PM

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.

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.

Jim Kaekel · 12-08-2014, 01:15 PM

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.

Mickey Whaley · 12-08-2014, 06:18 PM

plastic

Ed Wright · 12-08-2014, 06:57 PM

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.

SSDiv6 · 12-08-2014, 07:13 PM

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.

12-03-2014, 02:43 PM	#11
magnumv8 Member Join Date: Feb 2009 Location: Coraopolis, Pa. Posts: 172 Likes: 0 Liked 0 Times in 0 Posts	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

12-04-2014, 07:35 PM	#13
randy wilson Senior Member Join Date: Jan 2007 Location: N/A Posts: 882 Likes: 0 Liked 22 Times in 22 Posts	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. __________________ don,t have one

12-04-2014, 08:44 PM	#14
Jim Caughlin Senior Member Join Date: Mar 2002 Location: Woodburn, Or Posts: 679 Likes: 77 Liked 786 Times in 240 Posts	Re: steel or aluminum driveshaft? I agree that carbon fiber is probably better but not legal in SS.

12-05-2014, 11:01 AM	#15
Nathan Stinson Member Join Date: Aug 2006 Location: Nashville, TN Posts: 114 Likes: 29 Liked 4 Times in 1 Post	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.

12-07-2014, 09:16 PM	#16
1320racer VIP Member Join Date: Nov 2007 Location: New Jersey Posts: 2,628 Likes: 160 Liked 759 Times in 379 Posts	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. 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. Last edited by 1320racer; 12-07-2014 at 09:34 PM.

12-08-2014, 01:15 PM	#17
Jim Kaekel VIP Member Join Date: Jul 2002 Location: Michigan Posts: 1,226 Likes: 133 Liked 529 Times in 107 Posts	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. __________________ Jim Kaekel 3836 STK

12-08-2014, 06:18 PM	#18
Mickey Whaley VIP Member Join Date: Dec 2006 Posts: 1,220 Likes: 0 Liked 1 Time in 1 Post	Re: steel or aluminum driveshaft? plastic

12-08-2014, 06:57 PM	#19
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	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. __________________ Ed Wright 4156 SS/JA

12-08-2014, 07:13 PM	#20
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 3,036 Likes: 710 Liked 1,538 Times in 575 Posts	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.