Miata wheel center bore 54.1mm, 200SX center for 59.1. What have I done?

I got some lightweight Miata 15 inch rims from a friend for a case of beer. I test fit them on the front wheel and it seemed to be fine. Found some R comps cheap and had a buddy mount and balance them for me. Finished the rear brakes and went to mount the new wheels. The rears don't fit. berkeley.

Options? Looks like I've got to remove 5mm of material. That seems like a lot. I tried one 4mm space on the rear and that didn't help. Doubling them up might help. Has anyone done this? It's a pain as I'm out the mount and balance fee; not cheap up here. And I need to track down some wheels.

The joys of auto racing.

Are you sure it is 5 mm? Seems like it would be 2.5 mm, because you are taking that much all the way around, increase the radius 2.5, and it increases the diameter 5. Machine shop can do that for you, how thick is the center of the wheel, and what kind are they? You probably ought to get all four done so you can rotate the tires. It would not throw the balance off too much, removing material from the center, but I doubt a machine shop would do it with the tires mounted.

Early 914 wheels have a smaller hub than the later ones on the front disks. You can get the 00 part number Pedrinis machined to fit where the 01 part number is needed.

You might have problems finding a machine shop willing to try. Even bough they are more than capable, they don't want to take the risk. It's why I had a hard time finding a shop to make my conical hub rings. Finally found a guy willing to do it. He was kinda skeptical at first, until I told him, "don't worry man, I'm a real American, and don't plan on suing you. If it breaks, it's on me." He chuckled and said "i like you."

You can open that up with one of those cylindrical sanding discs on a drill. The discs I'm talking about are the ones that attach to a rubber cylinder and go on a drill press.

A wheel repair shop might be able to help.

Could you use some spacers to move the wheels out to fit?

Miata wheels are already in the perfect offset range for the 200SX (NICO forum says +40-47 is acceptable range, and Miata wheels should be about +45). You COULD mess around with larger spacers for the rear, but then you will have rather uneven front and rear track widths and your racing class may or may not prevent you from running them anyway (look this up first!!!). Plus quality spacers might outprice any mount and balance fee. The "right" solution would be to have the wheel centers machined down, or find different wheels.

BTDT. Tedious but you can wallow out the centers with a die grinder. Use gear oil for cutting fluid and the burr won't pack up, cut like butter. You will need to go oversize unless you have Terminator genes.

One hole saw cup inside another. The inner should fit in the original bore of the wheel and the outer should be slightly bigger than what you want the bore to be. Teflon tape on the inner to smooth the teeth and make it a snug fit. Lube generously and use a big drill. You only need to go deep enough for the register on the wheel, and by leaving the outside bore alone you should still be able to balance the wheels with a regular spin balancer.

Edit: With a powerful drill and good hole saw it will go fast, so be careful.

Thanks all. Yes, 2.5mm of material removed. When I typed it last night I was still in 'what an idiot' mode.

I'll try and bore these out myself. But I'm going to splurge on a new set of rims and tires as well. I wanted a second set, but was hoping to wait until next springs season.

There are YouTube videos of wheel centers being enlarged with a router and a good quality carbide tipped cutter.Someone on here needs to try that and report back. It may as well be you.

I paid a machine shop to bore out my C1M wheels from 54.1 to 57.1 mm for the Saturn. It was a pain finding a shop, but they did it for about $150. They work great on both cars now (I have centering rings for the Miata).

I bought a flycutter and mounted it up in a cheap big drill press. The flycutter cost more than paying a machine shop to do the job, but I now own a flycutter that I haven't used for 5 years. Seems right, don'cha think?

What kind of lug nuts do they use? If flat/washer/"mag" seat you have to have them bored out by a machine shop. A conical/ball seat wheel should be happy running lug centric so you can just hog them out however you like in that case.

The rims are lug centric. I made sure of that before doing anything.

I bought a file bit for my drill at Crappy Tire for 5 bucks. About 15 minutes a wheel allowed me to put them on with one 4 mm spacer. I'll probably spend another 10 minutes on each wheel so I can run them without spacers if I want. Oh, and the fronts needed the spacers and ream job too in order to fit. Like I said, not my brightest work.

The good news is the car will be ready to run next weekend. I am stoked.

Thanks all.

Good work, just keep in mind that when you balance the wheels now, you need to ask them to put the centering cone on the outside.

In reply to mw:

You have to do that for pretty much all aluminum wheels, unless you're okay with huge scratches/scuffs on the face of the wheel.