Is anyone aware of SAI, Steering Axis Inclination?

Straight down the centre of your wheel and the centre of the shock, imagine 2 lines, these lines eventually meet if you follow them down, this is the SAI offset.
0 offset is the ground, negative is above ground and positive is below the ground.

If you take the point where these meet this is your SAI angle.

If you adjust your camber, wheel offset, height and so on... this changes your SAI angle.

If you have a negative offset you steering wheel will be harder to turn, but you will feel the road more and if you have a positive offset your steering will be lighter, but you won't feel the road as much.

I'm not sure what the OEM angles are but i have lowered my wheel ET by 5 mm, have 1.5 camber all over and coilovers, so based on what i know, my SAI angle will be more positive, meaning lighter steering and less feel.

Ideally i would like feel to driving my car.

Has anyone else thought about the effect of all of this before and know any details about Subaru SAI angles?

Thanks

 

Hmm, but if you change the camber, the wheel and strut all move, so i don't think this effects the SAI angle.

Just having a little think out loud here.

Thanks

 

did this at college, over 10 years ago now, cant remeber anything lol

not much use, but follow with a bit of interest.

 

I think it's real good use if you want to make the best handling car possible and not ruin your road car, but then again it all depends on what the OEM angles are.

Thanks

 

On camber adjustable coilovers, yes but when camber adjustment is as per standard strut ie at the hub, the SAI would change?

JohnD

 

Ahhh yeah!

Thanks