Here's the situation. I've come across a set of BBS rims off an FC RX-7, 15", 5x114. The smaller Mazda centre bores were machined out by the previous owner but each wheel happens to be a different size.

So I'm planning to machine all four centre bores to the same size and use hub-centric rings. Just wondering what size to machine them to. The most common hub centric ring size? Or the most common aftermarket bore size? BTW it's for a USDM ITR setup (ie., 64.1mm hub bore)

Thanks in advance for all your help.

 

Wow, so you're taking a wheel that doesn't normally fit, AND which someone else has screwed up machining? Are you SURE this is what you want to do???

If something sounds like a bad idea, it usually is.

 

Just get them all machined to the same as the biggest one right now, and have your machinist spin up 4 aluminum hubcentric rings while you are there... that way they will fit perfectly.

And like noted above, you want to make sure that the last person did not damage the wheels beyond safe limits.

 

I know the guy who did the original machining and it was a clean job. It was the previous owner who did not specify what dimensions exactly was needed to be removed. So a couple of the rims went back once or twice to be re-machined but now the clearance is more than I'd like.