Lightweight Axles

[Jim Kaekel]

Has anybody actually seen any benefit switching to axles that have been gundrilled for weight reduction? I know in theory they should be quicker, be what about real world results that amount to a measurable amount of difference. Thank you in advance

[Harry 6674]

I didn't actually see a change but you have to believe all the little reductions add up. So does the cost. Is it worth it? If you want to be all you can be I guess it is. Thats what the army says.

[FED 387]

Think of it this way for every pound you lighten on a rotating mass the engine sees it as a 4 times reduction --the further out rom the center of rotation it can multiply even more---so if you take out 2 pounds of axle the resistance that the engine has to overcome is approx. 8 pounds plus the car actually weighs less also--Comp 387

[GTX JOHN]

I have never noticed an quantifiable difference.....quit putting them in any of our cars about 5 years ago......not saying there is not something there just have a lot of other places to throw money at for us!

[John Mason]

Several years ago I put the whole lightweight rear package in my 3600 lb. A/SA Camaro. Aluminum spool, lightened ring and pinion, rifle drilled axles with all extra metal removed from the flanges, titanium studs, etc. Took 24 lbs of rotating weight out, put 24 lbs in the box.
Total improvement was ----------------------- nothing!!!!!!!
Nothing in 60', 330' or anywhere else.
Might be some help in a lightweight car with a low torque engine, I don't know, but no one I have talked to ever said they picked up anything except a lighter wallet.

[Signman]

Originally Posted by John Mason

Several years ago I put the whole lightweight rear package in my 3600 lb. A/SA Camaro. Aluminum spool, lightened ring and pinion, rifle drilled axles with all extra metal removed from the flanges, titanium studs, etc. Took 24 lbs of rotating weight out, put 24 lbs in the box.
Total improvement was ----------------------- nothing!!!!!!!
Nothing in 60', 330' or anywhere else.
Might be some help in a lightweight car with a low torque engine, I don't know, but no one I have talked to ever said they picked up anything except a lighter wallet.

That being said, reducing unsprung weight had to help suspension. With shocks and springs seeing that much less weight to help them work better in keeping the tire planted. May not show up on the ET Slip as HP to the wheels is increased only very slightly but car may have an easier time getting down a marginal track which could show up in win lights.

[Wade_Owens]

If I had to purchase ANY rotating suspension/drivetrain part right now, it would be the lightest I can find......

(then, I may even cut on it!)

Wade O

[Ed Wright]

I'm with GTX John and John Mason. I've put all that in mine and found zero. Did, however clean the splines out of the aluminium spool on the starting line at Memphis two years ago, 1st round of eliminations. Had Byron Latino on the tree too. :-(

Jerry Hass was with a red Hemi car parked across from me. He walked over after everybody got back. He said he was standing by my car when it happened. He asked if I broke an axle. Said I didn't know yet. He asked how many splines, I said 35. He shook his head and asked if I had an aluminiuim spool. I said yes. He says "There you go, stop throwing your money away there". He said he quit putting that stuff in cars he builds, no gains, but sometimes problems. I saw zero change in 60' or anywhere else. I put my steel spool back in.

Just my exprience.

[Bill Edgeworth]

Listen to Wade.

Lightest AND smallest diameter.
Taking two rotating parts of the same weight lets say a solid axle verses a larger diameter gun drilled axle the larger diameter part of the same weight takes more energy to accelerate to the same speed. In fact a lighter part that is significantly larger in diameter can take more energy to accelerate.

Here is some casual reading on the subject;

http://en.wikipedia.org/wiki/Moment_of_inertia

Now when it comes to aluminum verses steel spools I think there is much more too it than rotational inertia. I think flex and friction may play a big role.

So just build your whole drive train out of titanium then we can start talking about $200,000 stockers LOL

[FED 387]

Most manufacturers specifically recommend NOT TO USE aluminum spools in cars that weigh over 2800-3000 pounds ---You MIGHT get away with an aluminum spool in a heavy (over 2800) car if it is a real LOW HP car---No hi torque hi HP applications for HEAVY CARS using aluminum spools- No trans brake/stick shift cars either--Rotating mass is where its all at---In stock/SS stock applications yer not looking for that last hundreth or thousandth like in a Comp/Pro Stock Application--that is the most likable application for aluminum spools/lightened ring gears/scalloped flange rifle drilled axles NOT stock or SS---Comp 387