VAP

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I only gun-drilled the fronts as I just can't continue to remove rear weight if my 50/50 front/rear bias is to ever become a reality. Front axles are hollow in the middle except for about 7" inset of both splined ends. I used an 8mm gun drill and drilled both ends of both axles into their hollow mid section then blew out shavings with compressed air and high pressure water. Weight removed is just at .5lbs (7.968ozs) per corner. I then sealed the drilled openings at each end with silicone so no CV grease is siphoned or migrates out of the CV's and/or water can't get inside the axles.

All axles were bead-blasted to bare metal before powder-coating then a 2-3 thousandths layer of polyurethane, instead of polyethylene powder was applied. Color-match is dead-nuts perfect in direct sunlight.

Tomorrow I'm going to electroplate my own inner/outer lightweight/motorsports CV's in-house with some (supposedly) titanium-colored new zinc plate I'm experimenting with. If it doesnt turn out the right color I'll just paint the inner/outer CV exteriors with epoxy and bake it on.

I'm trying to get these done for a weekend installation. I need the ones on my car now for building suspension jigs for the upcoming struts. Sometimes ya just have to take a few days off to make a shiney-new trinket or two for yer own car!

UrbanAssaultAudi

yeah, thats what you call pure sex right there...

Lago Blue

&amp; what are those 2 ribs for, on each of the fronts, slightly towards the outboard ends?

Are they different lengths &amp; not inter-changeable? Which where heavier, fr. or rr.?

As well as drilling, could the rears' O.D. be turned down to the smallest diameter (as seen just inboard of the splines in the photos), all the way across between the splined ends?

If you did drill the rears, could/would you add that same weight removed lower down &amp;/or farther back? Adding weight down low sure used to work well on slot-cars. For instance could you lay your battery over &amp;/or lower it so that its bottom is flush w/the bottom of the gas tank? That work could surely add a few half-pounds, or are there other rules/concerns/principals WRT to "added" weight?

Thanks, just curious.

VAP

Fronts are hollow, slightly lighter and stronger (more resistant to twisting) than the solid rears. The rings are where Lobro welds them, same design as on stock drivshafts where their splined ends are welded to the driveshaft tubes.

Hollow/Tubular fronts weigh 4lbs/8ozs stock and rears weigh 5lbs/5ozs. For a solid axle to be as torsionally rigid as a tubular one it would probably have to weigh twice as much as it does now.

Rears are interchangeable left-to-right but fronts are left/right-specific as one is approx 5/8" shorter than the other. None can be swapped front to rear or rear to front.

Since car is biased with more torque at the front coupled with twice the weight of the rear of the car is why it gets heavier-duty axles that are less prone to twisting. That's also why, least on the B4 90Q it has larger outer CV axle splines up front than in rear.

Rears could be ground down but would have to be re-hardened and it would weaken them. By gun-drilling my fronts I've likely increased their resistance to twisting and not made them weaker in any way as I only went for a VERY conservative 8mm bore. Rears could be drilled the same way with an accompanying increase in torsional rigidity. But no sense removing any weight off the rear if I'm only going to add it back somewhere else. And ballast for weights sake is already about as low as you can go if it's allowed to remain in the axles. No sense making even more work for myself.

My battery will be lowered within an aluminum box but not until engine is finished and final body work and total re-paint begins as ala carte visits to the body shop get expensive!