Tracking a car with wheel spacers?

This might look like an odd question but keep in mind that I grew up in Germany and in general wheel spacers on cars there are frowned upon by safety inspectors and I never got over my "fear" of them.

Basically, I need a set of 15x7 wheels for my fun & track Miata. Originally I wanted 6ULs but the size and color I want is currently out of stock, so I'm trying to figure out if I bite the bullet and get some gold RPF1s from Good-Win-Racing, cheap out and get a set of Rota Grids or, well, wander into my shed in which I happen to have a set of BMW 325ix OEM BBS wheels in halfway decent condition.

Caveat - I have no idea how heavy the BBSs are and really need to weigh them before I make a final decision.

The main issue with the BBSs is that they are the ix offset (41) so I'd try to run them with at least 5mm spacers to push them out a little further. I know that I need longer wheel studs if I exceed a certain spacer thickness (I think once I go above 5-6mm) but if I get decent spacers and the longer studs if necessary, are they going to be OK on the track with 200-ish threadwear tires?

I ran 33in toyo open country MTs extremely hard... Burnouts on road and a lot of offroad abuse. They were 1.5 in aluminum rigged up Offroad units. They had studs on them and once torqued down I just bolted my wheels to the other stud set. I did lunch a wheel bearing and always wondered if it was the spacers fault putting more strain on them.

I had a friend with 3 in steel spacers on a dually he was 8k lbs. I've never seen them fail.

FranktheTank wrote: They had studs on them and once torqued down I just bolted my wheels to the other stud set.

can you do this to change the bolt pattern? I'd really like to change the back wheels on my datsun replica to match the front.....I have four lug datsun wheels on the back and five lug dodge wheels on the front. (I used a front clip out of a dodge dakota so I could get a double wishbone and not have to screw with the ackerman angle)

I've seen a bunch of adapters that work that way, for example from 4x100 to 5x114.3...

TRMotorsport C1Ms? 15x7 +30, light, cheap. Made for Spec Miata. At like $90 a wheel they're probably cheaper than a set of spacers and studs.

There are hundreds of Miata-based Exocets running around with 30+mm wheels spacers with no problems I've seen. Granted, they're probably ~900lbs lighter than your Miata, but you probably won't have issues with only 5mm.

Track Miatas run hard have a tendency to eat their front wheel bearings, just be cognizant of temperatures and any slop that may appear.

As far as increasing the loads, spacers will not greatly affect the moment generated at the hub from pure side loads. Normal (bump) loads will generate a larger torque along the car's longitudinal axis, but that is opposed to the torque generated by lateral grip on the outside wheel. Your steering geometry will be affected with a larger scrub radius and what will feel like a shifted kingpin axis. Basically, more steering effort and feedback.

I run spacers on my EP RX7 (roughly 10mm) with no issues. This is a 2300# car running on slicks and racing SCCA Nationals. You should have no problem.

Wait and get the 6UL's. They are great wheels (but fragile for DD use) and perfect for a Miata.

The BBS wheels should come in at around ~15lbs

That said, use a torque wrench and you should have no problems with spacers

It is much better to simply use wider wheels. I have used a pair of 10mm spacers on my M3 for years without issues but they add 4 potential causes for the loosening of the front wheel bolts as well as potential vibrations.

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We ran them on our racer years ago. No problems at all.

when on track I run 13" w/ R-comps ... to clear the caliper I either have to use a grinder on the caliper ( for some reason I just don't like to grind on my calipers ... even though in this case it wouldn't matter) or use a 1/4" spacer ... I've never had any problems ...

I've seen people get away with all kinds of wacky ghetto spacer setups on the track.

I ran 5mm spacers on my ZX2SR. The Hoosiers rubbed on the rear strut.

Should be just fine but you can always source/have them made hubcentric and then for sure its all good.My new wheels for the E30 JUST kiss the back of the spokes on the front caliper brackets so instead of grinding I ordered up hub centric 5mm spacers for peace of mind from http://www.8380labs.com/

and to solve the short lug problem ... 2 choices

1) extended length lugs

2) this ... http://performance.importrp.com/eibach/eibach_pro_spacer/906150091/i-98501.aspx

If they are hubcentric, you should have no reason for concern. Have them on the ZX2--no issues.

I ran 5mm spacers on my E Stock MR2, autocrossing on r comps for years. I know a lot of people did. Mine weren't even particularly good spacers. If you do some nice, hubcentric spacers like ^^^ I can't imagine you'd have any problem. Just make sure, as you said, that you have enough lug length.

mr2peak wrote: Wait and get the 6UL's. They are great wheels (but fragile for DD use) and perfect for a Miata. The BBS wheels should come in at around ~15lbs That said, use a torque wrench and you should have no problems with spacers

I always tighten the wheels with a torque wrench so I have that part covered...

I'd normally just get the 6ULs but the size I want isn't in stock (15x7). Mind you, they have 15x7.5 in stock so I might give them a call about those...

Part of the problem with waiting is that I have a trackday booked at Laguna Seca at the end of the month. That puts a bit of a damper on the "waiting" part, hence the idea of throwing the tires on the BBSs, put those on the car and remount them on the wheels I was after once I can get hold of them.

I run 10mm spacers on my RX7 because the basket of the wheel doesn't clear my calipers. I haven't put a ton of mileage on the setup, but with 10" slicks I haven't seen or felt any degradation of parts.

You can also buy the Konig's from good-win-racing, 12lbs, 15x8 $109 each. That's what I'm running.

I'm kinda of curious about the idea from another poster that somehow a wheel strong enough to deal with racetrack abuse (temps, curbs, lateral loads) is somehow not suitable for street use?