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.

[Bean]

Didn't have the same setup but something similar - the only proper solution are longer lower arms. Just fitting spacers makes the wheel move in an unnatural arc.

You might be able to get away with a combination of your solutions lower ET and slightly smaller wheels. I would go for lower cross section on the tire rather than narrower tires. Basically what you want is less diameter overall

[bozu]

I posted this up on other forums as well and got some feedback that 15” 7J et0 rims with 195/45 tyres should clear. So that’s something I’m going to test fit.

[Project D]

I have a similar setup (manuel rack + PS knuckles) but I also have tie rods with extra steering angle (Nagisa auto)
With my 195/50R15 on 15x8J +0 wheels setup, the tires used to rub the inner fender / chassis.
Then I installed wider lower control arms (adjustable, but they are set ~+20mm) -> no more rubbing; at least for "normal" driving.

For drifting I use 185/60R14 on 14x7J +0 and no issue. Mind you, you will need to run a little bit more caster to not rub the inner fender and you will also have to flatten the seams.