Cutting down Wheels to fit

I have a set of BBS 360 challenger wheels that I need to shave down the offsets about 3/4" was curious if there is any guidelines in regards to how much material you can take off the wheel before you compromise the structural integrity of it. The wheels have about a 1" offset that the lug nuts go through that I am looking to mill down.

 

You will get two different groups on this. Some believe because they have not experinced failure you can take off the amount you need.

Others such as myself do not think the wheel manufacturers of this type of wheel leave allot on the table for xcess weith or material.

I also think it depends on how hard you are going to drive the car and under what conditions.

I feel this way due to my own experience with unmodified racing wheels that clearly stating not for street use failing on the street.

These wheels were magnesium which atleast when stressed showed hairline cracks prior to total failure thus preventing a major problem.

 

There's a member on this forum that has the 18" 360 challenge wheels on his 348. He shaved down the rear bit. I don't remember the exact amount, but do a quick search for it.

 

I dont think this is a black at white issue. You cant say 5mm is safe and 10mm is not since its all geussing. However, i would say it is a very dark grey issue.

My E55 benz wheel bolts are only like 1" long, meaning the hub depth is very shallow. 355 challenge wheels are 55mm long. Does that mean you can cut the hub down to less than an 1" on the ferrari wheels? No. Its because they were designed that way.

You mentioned in the picture thread shaving them down 1" and in this thread 3/4" i think that is way to much and your risk of failure is high. I would never do this.

I actually dont think you even need to mill this much anyway. stock 355 wheels are 77mm offset, but they are sunk way into the fenders, so much so, many of us here run 15mm spacers, which nets an offset of 77-15mm =62mm (and they are still tucked).
I think with the proper alignment, you could actually run up to 25mm farther out and still be slightly inside or equal to the fender, which would be an equivalent of 77-25= 52mm.
I believe stock rear 360 challenge wheels are ET40, so try milling off 10mm to maybe 15mm and try them.

 

I have regular 360 starfish wheels on my 355. Front fit fine. Rear, its been a while maybe use search feature, I think I had 13mm shaved off? also, you will need to spin up the rear shock collars to the top to give more clearance. Handles great though!!

 

http://www.ferrarichat.com/forum/attachments/348-355-sponsored-bradan/1634998d1356642741-nice-pic-my-355-other-week-image.jpg

 

Thanks for all the replies! I'm going to take off 15MM should be a nice fit. Thanks again

 

Allthough I dont agree atkeast that sounds more reasonable. Good luck