Wheel machining to change backspacing?

[POSYJ]

So the Grocery Getter I am looking at has forged wheels with some bad offset on them (rubs the fenders even after lip has been rolled). Forgestar didnt want to work with the previous owner and told him to machine the bolting face down a little to tuck them in....it looks like there's room on the inside of the wheelwell to clear and plenty of meat on the hub surface to trim a little (1/8" ish)....

anyone done this or had this done? where? cost? its just on the rears...you can kinda tell by the pic

[cool cat]

I'm interested in this as well. i have the same situation with some pricey wheels.

[Mach1]

i'd be worried at sacrificing the strength of area under the cone for the lug nugs

[POSYJ]

It really is pretty thick in the hub...I dont think its going to be an issue of strength (esp considering they are rotary forged vs cast (yeah I know RF isnt the strongest forging process, but its still better than a traditional cast wheel) - the hub is probably 2-2.5" thick...I would need to take it off to see the thickness of material from lug seat to hub face...but I imagine if forgestar suggested they be machined its not a concern???

[shumpertdavid]

It really is pretty thick in the hub...I dont think its going to be an issue of strength (esp considering they are rotary forged vs cast (yeah I know RF isnt the strongest forging process, but its still better than a traditional cast wheel) - the hub is probably 2-2.5" thick...I would need to take it off to see the thickness of material from lug seat to hub face...but I imagine if forgestar suggested they be machined its not a concern???

The portion of the wheel Mach1 is speaking about won't be 2-2.5" thick unless you're running a 3.5" wheel stud or longer. I understand what you are saying about the thickness as the "hub" part of the wheels on my Regal are substantially thicker on the rear than the front wheels. However I would imagine if you look, the lug nuts sit further down into the hub on the rear than the front. The determining factor will be the amount of material thickness from the inside flange of the hub portion to the lug nut cone, as Mach1 mentioned. If it were only an 1\8" thick (just using that number as a reference) and you machined off 1\8" then you would have no material for the lug nut to seat against.

I wouldn't think Forgestar would recommend doing this if there wasn't sufficient room, however don't just take their word for it. Double check measurements and only cut once. You don't want to screw up a set of wheels on someone elses word.

[Mach1]

if you run that beast in mexico it's not worth your life if a wheel fails at 150+

[90GT50]

A few degrees negative camber, done.

Or call wheels america and see if they'll do it.

[bird_dog0347]

Forgestar makes those in all sorts of sizes/offsets... Do they not already make the ones you need? Could you not buy new wheels and sell those to offset the cost?

[POSYJ]

car comes home tomorrow so I will take a wheel off in the next couple of days and measure the material thickness.

no runs in mexico until after the roads wash off and it gets some help from 21st CMC on the tune, but yeah I wouldnt chance it if the material isnt there to remove in the first place...

[NoClassic]

If it's just the rears buy two more in the proper offset and sell what you have.

[Lone Star Performance]

That dyno looks familiar! Great looking wagon and it was nice meeting you yesterday.

Scott from 21 CMC

[POSYJ]

Nice meeting you too Scott....calling tomorrow so should be seeing you guys soon...

[YALE]

It'd be cheaper to have Wheels America change the offset/back spacing, than pay what a machine shop charges.

[sickpony]

Buy some wheels that fit.

[Texas Track Works]

Give Bryce at Alamo Autosports a call (817-860-4300). He has done this with his cnc on a few sets of wheels for us in the past. The wheels he modified were used on a NASA CMC car for two seasons with no issues.