I just had an LS1 aluminum shaft installed in place of the stock steel one. Numerous posts have asked about the weight savings, rear wheel power gains and 1/4 mile difference but I have seen no hard data.

I asked the shop to make sure they weigh the aluminum shaft before installing it, and they promised to. When I picked my car up, they said they forgot. I wanted to smack him in the head with the steel shaft.

The stock steel driveshaft in our cars weighs 16 pounds. If anyone can weigh an LS1 aluminum shaft, please post the result so we can put this debate to rest.

 

the driveshaft is pretty darn easy to remove. Get a scale, remove it, weigh it.

 

I know but I live in an apartment and have no jack. Plus I'm too lazy.

 

the weight differance between 2 static parts isn't the big issue, it's the differance in rotating mass that is

 

yup, just how a trans can be heavier than another but still let more hp to the rear wheels beause of less rotating mass....

 

One pound of rotating weight = 7 pounds dry weight for 1/4 reduction. Yes that's why I bought.

 

Its not just the weight difference, but also the fact that aluminum is very absorbant of driveline disturbances. Less vibrations will be transmitted into the passenger compartment with an aluminum than with a steel.

 

I've never seen this formula before and have some questions.
If my 2-15x7 IROC rims w/235 60s weigh a total of 96lbs and a set of draglites w/25x4.5 frontrunners weigh 42lbs the difference is 54lbs. 54lbs multiplied by 7 is 378lbs.
Do wheels/tires qualify as rotating weight? Would skinnies be worth as much as 3 tenths? On a 12 sec. car?

 

Yep. Sweet huh! Drag wheels and skinnies are the single best weight reduction mod you can do.

 

I'll be pulling the driveshaft out of my 00 TA soon. Need to replace the rear pinion seal. I'll weight the shaft at that time BUT it will be weighed with the yoke and u-joints.

 

I'm not sure how much the aluminum ds weighs, but I can tell you that there is no sotp difference.

 

About 2# difference between the steel vs aluminum.

 

Well we weighed cg91ta's 1LE aluminum shaft and it's 12.0 lbs. It's a smaller diameter than the LS1 shaft so who knows.

 

When I changed mine it was about 4lbs difference.

 

can you explain this?

-Brian

 

Rotational weight is any moving part in your car, from engine to tires.

"As a general rule" (but of course not accurate in all situtions):

Any part of that you can reduce in actual weight results in your 1/4 mile time being reduced by 7 times more than if it were dry weight."

Ditching 100 lbs. of dry weight gets you a .1 sec. quicker time. So if you can gain .7 by ditching 100 lbs. of rotating weight, that's very cool.

Look at this site. These guys would smoke most of us. Notice they all have slicks and skinnies on lightweight drag wheels:

http://temp.corvetteforum.net/c4/bea...nSet-ups.shtml

 

I weighed mine when I put on the 1LE shaft.
Stock 2.5" steel = 16 pounds
1LE 2.75" Al = 12 pounds