Gear lightening

[Jeff Lee]

I have a dana 60 with all the good parts from MW; MW disk brakes, 40 spline gun-drilled axles, back-cut ring gear, CM axle tubes. What I do not have is an aluminum spool. I have a MW lightened steel spool. So for all my light parts that was one area I did not want to push. The bonus is every time a change a R&P for ratio it always looks new.
I'm still of the opinion these light parts are worth it however I have no back-to-back data to prove it.
I am looking at going from a 168 tooth flywheel to a 142 tooth flywheel. I guess that falls into that "center of inertia" theory Bill was talking about. From what I have read and heard, it will be worth the effort.
I hope...

[Bill Edgeworth]

Originally Posted by Jeff Lee

I have a dana 60 with all the good parts from MW; MW disk brakes, 40 spline gun-drilled axles, back-cut ring gear, CM axle tubes. What I do not have is an aluminum spool. I have a MW lightened steel spool. So for all my light parts that was one area I did not want to push. The bonus is every time a change a R&P for ratio it always looks new.
I'm still of the opinion these light parts are worth it however I have no back-to-back data to prove it.
I am looking at going from a 168 tooth flywheel to a 142 tooth flywheel. I guess that falls into that "center of inertia" theory Bill was talking about. From what I have read and heard, it will be worth the effort.
I hope...

I think the aluminum spools are real source of controversy exactly because of your observation of gear condition; is the very small advantage of the aluminum spool negated by the extra friction created by all the distortion that takes place with an aluminum spool?
I guess if someone really wants that extra 0.005 they can drop a few grand on a titanium spool.

I think your flywheel will be money well spent; it is any time you can lighten things up prior to any gear reduction. One of the other factors is that the flywheel gets accelerated 4 times in your stick car the spool only once. You should see it in your 60’ it’s a diminishing return thing through the gears. It takes way more energy to accelerate a part at 2000 rpm/second in first gear than at 600 rpm/second down track. It will be a little different animal though. With the same clutch setting your motor will pull down faster due to the reduction in rotating inertia.

I think even the tech department at NHRA has clued in on the center of inertia thing. I noticed with all the recent crankshaft chatter the rules state you can only add enough heavy metal to do a normal balance job. Not sure if that’s exactly how they worded it.
But if you were to turn a bunch of weight off of your crank counterweights and then add heavy metal to get the assembly to balance it’s going to be a faster piece. It won’t show up on the dyno but the motor will accelerate quicker.

[Dave Goob Cook]

When it comes to ET reduction from the rear end, I think the best money and time is spent on de-burring and polishing the gear sets, getting the lash and depth perfect for low drag on the load side, and careful attention to the details of the lubricants, and control of it, bearing loads, and bearing fit.

For the lighter vehicles, especially stick shifted ones with lot of ratio and operating RPM, it changes the priorities some.