Welding and machining aluminum wheels.

[rsr911]

OK as you may have guessed by my nickname I'm into Porsches except my income doesn't match my taste in cars Anyway I need to buy a set of track wheels for my car so that I can run DOT rubber at the track and not where it out on the street. The trouble is I'm tired of paying the "Porsche Tax" on everything Porsche related, kinda reminds me of when I built and raced Fords before the 5.0 craze dropped prices inline with Chevies. Anyway Porsche uses a 5x130mm bolt circle and an odd cup shaped taper for the lugs to seat into, I'd like to buy some cheaper wheels in a Chevy or Ford bolt pattern and weld up the holes then remachine. The question I have is will I significantly weaken the wheel? My brother has an industrial sized welder so I could get good penetration that I likely wouldn't get with my Lincoln SP 175 tig machine. The side benefit here is that I'm partial to American Racing Torq Thrust D's which are a modern version of the old Torq Thrusts from the 60's and 70's and where available in Porsche sizes back then. I'd like to run 17x8 and 17x9 to fit my big Brembo brakes and 13" rotors and just about every decent wheel with a Porsche bolt pattern is super expensive, the AM wheels are cheap by comparison. The machining part should be no problem, it's the welding that concerns me. Also I'd be stripping and powder coating the wheels to factory finish isn't an issue. I've got an Eastwood powder coat gun and an oven large enough for two wheels at a time.

[topct]

Will the rules permit this?

What if the welding caused some kind of embritlement to take place? Is there a possabilty the wheel might also be weakened because of the machining?

Interesting question. Has anyone else with these cars ever done this?

[rsr911]

Rules should be fine as there are guys running factory wheels modified from 16" to 17" by welding new rim pieces onto original centers.

Machining should not weaken the wheel as the bolt circle is only 3mm different from a 5x5" (5x127mm).

Embrittlement is my concern, I don't know what will happen which is why I'm asking. I only need to build the holes up enough to redrill 1.5mm off center and remachine the conical lugnut seat.

[bob308]

i have welded up some bust out bolt holes and remachined them in al. wheels also fixed some of the old corvette knock offs. and never had any problems.

[QSIMDO]

Perhaps easier to find lug nuts with correct thread to fit the studs and wheels
or just change the studs?

[GKman]

I would go with a very experienced aluminum welder. Is this something you want to "think you got a pretty good job on" or know you did. Of course you may get the cost of the higher priced wheels wrapped up in the cheaper ones. The one I have used says he gets suprised all of the time. Had him simply weld a 3/4" dia. boss on a V6 Ford aluminum intake manifold for another water connection and he spent over an hour boiling up crud out of the puddle, grinding it off etc, etc.

If it doesn't work, have the widow let us know.

[JCHannum]

Is it possible to by the wheels undrilled?

[smagovic]

Chris, Jim's idea is pretty good, or why not to have the wheel done custom. I can see on the TV so many of those places that make custom rims for any car. That would be safe -perhaps a little more expensive. But I do not expect that it will be easy to get a very, very good Al welder for a little money, namely when he will realize what it is really for. Good luck. Vic

[rsr911]

Perhaps easier to find lug nuts with correct thread to fit the studs and wheels
or just change the studs?

It's the stud spacing that is the problem and I don't want to change that.

It's important to remember here that I'm only welding to build up the area to machine new holes off center from the original holes, off center by 1.5mm. My big concern is heat damage from welding and how it will effect strength. These are cast wheels


JC, I'm looking into buying unfinished wheels without the holes drilled but haven't had much luck yet.

[rsr911]

Chris, Jim's idea is pretty good, or why not to have the wheel done custom. I can see on the TV so many of those places that make custom rims for any car. That would be safe -perhaps a little more expensive. But I do not expect that it will be easy to get a very, very good Al welder for a little money, namely when he will realize what it is really for. Good luck. Vic

Custom would be nice but would eliminate any possible savings which is my whole reason for this endeavor. I can buy all sorts of nice wheels both custom and stock but then theres that "Porsche Tax" and "Custom Tax"