Inside of front wheel touches frame rails during drifting

[bozu]

Hi guys (and girls?),

I’m looking for some feedback from people on the forum that have experience with running power steering knuckles on a manual rack and the effect this has on the clearance between the inside of the wheels and the frame rails.

My setup:
I have a manual rack AE86 with power steering arms and currently running 15” 7J ET20 rims with vredestein 195/50 tires on the front. Car is slightly lowered using coilovers.

From what I understand this knuckle and rack combination gives you more lock/angle. How much more angle I can’t find information on.

During drifting I recently noticed the inside of my front tires are rubbing my frames rails. I did some investigation and it appears that during normal driving the inside only just clears on full lock.

But due to the weight shifts during drifting the suspension is unloaded on one side, the wheel drops and starts touching. On full suspension droop the tire touches significantly.

I did some measuring and, assuming my calculations are correct, at full droop I would need 16mm spacers as a minimum. This is not an option as this would cause the outside of the tire to touch the guard/fender.

Based on this I see three possible solutions:
1. 165/50 tire on current 7J rim, but this is very stretchy so not sure if it drives properly and is safe during drifting.
2. 175/50 tire on 6,5J et16 (other rims that I have)
3. 175/50 tire on 6J rim with max et7 (would need to buy this custom size)

Does anyone know the extra lock/angle power steering knuckles give you when used with a manual rack?

Has anyone run this rack and knuckle combo and can confirm which wheel and tires combo/spec will clear the frame rails? I prefer to run 6,5J rims instead of 6J but I’m not 100% sure option 2 will provide sufficient clearance.