Gear lightening

[Whalen3186]

Approximately how much et is a set of lightened gears worth? Is it worth the extra money to have this done? Thanks

Drew Whalen

[FED 387]

just remember one thing however much weight you remove on a rotating part the engine thinks that it is actually 4 times that amount that it has to overcome---probably not a very significant amount of et but when coupled with weight removal in many parts it does add up to reduced overall et-- any competent machinist can lighten a ring gear---Comp 387

[NovaMan]

What do you do? Turn down the OD?

[John Mason]

I'd be curious also. On my A/SA Camaro (12 bolt Chevy) I put in a lightened gear set, aluminum spool, rifle drilled axles and lightened axle flanges. 18 lbs reduction in rotating weight for a total difference in ET of -- wait for it ----
NOTHING!
0 in 60', 0 in 330' and so on. Lower HP combo's may see a difference where higher don't.
I think as the distance from the rotational center decreases where weight is removed it has less effect. There seems to be quite a difference in lighter wheels and tires, but look where the weight is being removed.

[Ed Wright]

John, I just went through that this summer and saw the same thing you did. Nothing. On top of that I cleaned the right side axle spines out of the spool on the starting line 1st round at the Mid Souths at Memphis. Only good light I've had all year too. Byron Latino didn't mind it too much.

When I tore it down, it also had a tight spot when turning it through, the ring gear flange had developed .007" run-out. It was straight when installed. Don't need any more of that crap.

[EMMONS MOTORSPORTS]

I couldn't agree more. IMO, the closer to the center driveline the less 'noticeable' difference. We have not seen an improvement in E.T. One of our stockers had a 12 bolt Posi with stock axles and we tricked it out with the latest and greatest (and expensive, too). It might be worth something when combined with many other factors. It could simply be more reliable.
We do it because everyone else does it and who wants to give up a questionable .005!

EMS

[FED 387]

I'm not promoting it as a surefire way to lose a TENTH but if used in combination with many other "tricks" it usually does add up to a reduction in overall ET--Isn't that what its all about anyway??? you lose a hun/thou here and a hun/thou there add it all up and pretty soon you have consistently lost several hun/thou in you overall ET Comp 387

[Dave Goob Cook]

The lower your HP/Torque is, and the higher your starting line gear ratio and operating RPM is, the more difference it would make, and almost never would you see much of a gain in a torque converter equipped car.

Moment of inertia is the critical factor

[Ed Wright]

At Memphis when I killed mine, Jerry Haas walked over to my trailer when I got back (I almost fainted) and said he was standing up there when it happened. He asked what size axles I had. I told him 35 spline. He said it shouldn't be an axle, then asked if I had an aluminium spool, I said yes. He told me it was the axle splines in the spool that gave up, and that he no longer use them in anything, that he never saw any gains, only a source of problems. He asked "What did you save, 5lbs?" I said exactly five. He said "Save your money next time." I'll take him at his word.

Didn't have nerve to ask for an autograph.

[340Cuda]

We took 41 pounds of rotating weight off our car with disk brakes a few years ago. Sure does stop a lot better but it does not go any faster.
Bill