Guys I've been wondering about this.. myth or fact:
Do wheel spacers take a toll on performance / are they unsafe for use on high performance events like the track?

2 kinds of spacers: Slip on (usually thin ones like 8mm) and bolt on with own studs (15-25mm)


J.C.

 

As long as the lug nuts fully engage your probably ok. I wouldn't go too thick and make the lugs only engage 2-3 threads. Then you'll have a bad day. People with more experience chime in

 

Most manufacturers say no more than 1/4" on oem studs. That 6mm, not exactly a huge difference.

As for performance, they shouldnt add enough weight to make a difference, although unless you're using them to fit over the BBBK, they're really only for looks afaik.

 

a good spacer is generally no worse than a wheel of similar offset:

So a wheel with +30mm and a 5mm spacer will be no worse off than a +25mm wheel of exact same dimensions and weight. With that said, I don't know about the huge ones (25mm+).

Lower offset is generally better for performance up to a point. If you look at spec miatas, it seems the ones running +25 or +20 had a slight time advantage over other spec miatas running higher offset.

In more technically terms, lower offset means wider track. The track width is a calculated part of the suspension geometry, and generally a wider track will lead to less weight transfer. Its generally better to have a wider track, but there are some limits of course. I don't really know what they are for the miata, and I can't tell you everything that a wider track effects (it does have an effect on center of gravity and how it changes as weight is transferred), but some simple terminology and google will get you pretty far.

I would try searching for (combine any two terms below):

weight transfer
track width
Center of gravity
offset
body roll
roll center

 

thanks for the replies guys. I was only asking because I recently traded my ridiculous 0 offset 8" wide sportmaxxes for some 15x6.5 slipstreams.. only thing I'm not used to is the high offset of +40. Thought I'd use spacers on em and wrap em with 205-50's.

 

Spacers add weight, but not that much. I don't trust spacers, I have seen a few studs snap before, I am assuming that it wasn't a good quality spacer. HnR is a good runner up, I never heard of anything bad about them.