I don't know if any of you have experience using these, but I've never heard it discussed here on s2ki before.
Perhaps Xviper will know...
Here's a link to the part (for a Mustang) and what it does. ---><spacer>

The reason I'm asking is my front rims make contact with the upper inside part of the A-arms when turned all the way left or right. It almost clears. I tried an aggressive set up on the front to see if it would give me an advantage in autocross (17x9JJ +65).

 

I've never used these, but I see it as your rims/tires that are the disadvantage since it is these that rub when at full lock. Limiting your turning radius would be a disadvantage on an Auto-X course, no? Don't you want the ability to turn as sharply as possible during certain manouvers?

 

I don't see how that product would be used to limit turning...

Do both wheels rub equally? If not, then maybe your steering rack isn't quite centered.

 

I don't think they would be a disadvantage because I don't think I ever turn my wheels to full lock during the actual race. Only in parking maneuvers. I believe it is only rubbing on the last 2mm of turn, so I don't believe I will notice the difference in my turning radius.
The other two alternatives I can think of are: 1.Putting spacers on the hub, which would made the offset less severe but which would probably cause more contact with the fender.
2. Buying expensive aftermarket A-arms from Spoon or some other manufacturer that would make the 1-2 mm difference ( I believe this is why the race teams in Japan don't have trouble with running a 9 inch wheel in the front for Gymkhana).

Or of course, I could find a buyer for the 9" by ordering a full set of 7.5" and halving the order, making two sets of the correct 7.5f and 9.0r I'm currently running 9" all around. (these tires are only used 1 weekend of the month for track).

Oh well, I think I'll just order those plastic doughnuts and give it a try. They're only a couple of bucks each.

 

Just fyi, but you don't need exotic Spoon parts for the A-arms; contact krazik, davepk, cthree, or rlaifatt for some other options (designed to get more camber, but should work for your needs too).

Otherwise, sounds like the spacers are the way to go for now.

 

I still can't picture what the donut does, or where it goes...

 

I believe on the 5.0L Mustang rack, The limiters install behind the inner tie rod end and the housing.