I put K-mac adjustable control arm bushings in all 4 of my arms years ago but to be ST autocross legal now you can only make two arms adjustable.

I want either some fixed length after market control arms or options to replace the K-mac adjustable bushings with non adjustable bushings.

I would prefer a non adjustable aftermarket arm as my first choice or an upgraded rubber bushing as a distant second and poly as a third choice.

What are my options?

 

I would put the stock upper control arms back on, and run either the adjustable lowers you already have, or look into H-sport adjustables as well as the Helix arms.

The upper arms will basically do toe adjustments in the rear, put the stock ones back on and use the 3 13mm bolts at the front of the rear trailing arm to adjust toe, while using either option of the H-sport or Helix arms for the lowers to adjust camber.

The H-sport arms are double adjustable, but use a poly bushing on either end, which are good for low maintenance, less transmitted noise/feel, and will be more oriented for a daily driver to mild track use.

The Helix arms use spherical bearings at either end, and are double adjustable as well, but will provide a more connected feel, as there isn't the deflection of the poly bushings.

Here are a couple options we offer:

http://www.detroittuned.com/h-sport-...arms-set-of-2/

http://www.detroittuned.com/helix-control-arms/

They cost near the same, but will have different outcomes for you, if you're looking for the most track oriented setup I would recommend the Helix arms.

Nick
Detroit Tuned

 

Converting from a regular bushing to a spherical bearings such as in the case of the control arms is not legal in SCCA STX class auto-x.

Are the K-mac arms even legal? Bushings in the aftermarket arms have to maintain the same ratio of metal/bushing as the stock bushings. I can't find any pictures with a quick google search to know what the k-mac bushings look like. As far as I know the only STX legal options are the h-sport control arms. That's what we're using. They also sell "rebuild kits" so you can replace the bushings in the h-sport arms when the poly bushings eventually wear out. Ours lasted about 1.5 seasons.

I would also just put stock control arms back on the top. Cheap and easy solution and I doubt you're leaving anything on the table with regards to performance.

 

Thanks guys, the very first set of arms I hot were the helix arms and removed them for class legality then got the K-macs put in all 4 stock arms. They are legal but a pain to adjust the top ones. I then got 4 H-Sport arms.

So my problem is that I no longer have any unmodified stock arms. Mini has no replacement bushings for them, they will only sell you new arms with the bushings already in them.

If there is an aftermarket bushing I'd like to find them but as I said before my first choice is a non adjustable aftermarket control arm.

Thanks for the suggestion on the H-Sport rebuild kit.

What I may do is just get a couple of rebuild kits, even though I don't know if I need them yet and weld up the H-Sport arms to to make them non adjustable and stock length.

The H-Sport arms have been on for something like ten years and 100's of autocross's. My mechanic says he has never seen a problem with one, though I have heard other people say they have.

 

The rules say "On double/unequal arm (e.g., wishbone, multi-link) suspensions,
only the upper arms OR lower arms may be modified or replaced,
but not both. Non-integral longitudinal arms that primarily control
fore/aft wheel movement (e.g., trailing arm(s) or link(s) of a multilink
suspension) may not be replaced, changed, or modified."

I'm not sure welded up H-Sport arms on the top would be legal. I read that rule as requiring OEM arms on the top. For locals I doubt anyone would care however I wouldn't make a trip to nationals with them in there. Call up Courtney. I'm sure he has some of those OEM control arms laying around. They can't be very expensive used. You can sell your other set of H-sport arms and probably break even.

This is the amount of play my control arm had when the bushing went bad in my h-sport arms. I'm sure it was a gradual failure but this is when I finally noticed it.

 

Thanks, I agree, guess I needed to read the rule again and I already asked Courtney and they have none there. Maybe I can get lucky and find someone that will swap me their stock arms in good condition for my arms with the adjustable K-mac bushings in them.