Offset bushing and wheel fitment discussions
 

Slightly off topic, but Mazda is now selling offset bushings and they are now legal for Spec Miata. Get yer cambers!

Mazda offset bushings

The prices listed are the racer discount prices.

Yeah, I heard that rule was changing. These look like the ISC pieces. I know they work with 15x7, not sure about 15x9. I've got a Mazdaspeed account now courtesy of NASA TT.

We tried a set of the ISC's a long time ago with 9's. They do not play well together. So we made our own acetal lower offsets. This (complete acetal kit) is one of the many projects on my list.

Well . . . dang it . . . hurry up! LOL.

Emilio,

Could you elaborate on the clearance issues you ran into with ISCs and 9s? would spacers help?

I was about to embark down this path based on another thread on M.net, but it sounds like you have better intel.

Wheel hits tub sooner than it does already. Not rocket science, just go look at your car and picture the wheel tilting in further.

Spacers help tire clearance but create their own problems with wheel rate, instant centers, ackerman. I try to stay away from spacers whenever possible.

Gotcha.

I'm building up an NB sub frame off the car so I couldn't really mock it up to look. I'm already running your 11.75" fronts with the spacer you provide so I thought I would ask. Thanks!

If you have an NB subframe, you may not have this problem in the first place. NA subframes are usually the ones that give camber limitations.

NB's also

John what do you mean?

I just bought a set of ISC's through a group buy, but I'll be running 9's. Shall I sell them to someone running 8's?

I meant that NB subframes are limited also. ALL of this depends on ride height also. I had 3.5* neg up front with no offset bushings at 3.75" pinch weld height and you could not have ran offset bshgs in the uppers with 9's as the 9's were rubbing a little without offset bshgs. I have sense raised the ride height 1" [12" frt, 12.25" rr don't know the pinch weld measurement] for this season with the new shocks. I am running these bshgs in the front lower arms fore and aft and am running 10" wheels and 245 tires with no issues. I would not want the offset bushings in the upper arms as having them in the lowers still tilt the upper tire closer to the tower but not as much as upper offset well. Its the first 2 listings as the 3rd is uppers. SuperPro control arm bushings - MiataRoadster - High-performance customer service...and parts for Roadsters

NB on an NB subframe here. I had/still have camber issues. Initially I had something bent as my camber & caster were very low on one side (<2* camber and <4* max caster at 4.75"-5" ride height).

I swapped stuff, including the subframe from another NB, that fixed both. now i can get gobs of caster (6.5* or 7*?, been a while) and about 2.8* camber on one side and 3.2* on the other (~4.3" ride height).

Details on your install? How are you keeping the inner sleeve from rotating? Did you pin it somehow?

You can't. We tested those back in 2007. Didn't work then, don't work now.

They are installed with the offset to the inside [3 o'clock position] and have had no issues at all with them trying to move as the strain on them is straight on. I can see if they were installed with the offset in any other position they might be wanting to turn. They have been on for numerous track days and rode hard.

Hornetball I reread your question and the inner sleeve is meant to turn inside the bushing, that is why there is teeth on the ends. These aren't meant to work like a stock bshg. You grease the inner sleeve with supplied lube. How long it stays lubed is another question?, but as my car is not driven on the street think it should be a non issue for quite awhile.

I might also add that the rear bshg isn't really needed unless you are tinkering with caster. As for camber it only gains you about .2* to .3* .

Like me...?

Yup. I was peer pressured, Didn't even want them.

Oh well.

Edit: then I realize that you mean I should sell them to you. Sure thing if you want them.

Eh, maybe at some point. get your car up and running and see if you need em, then talk to me.