Subframe Bushings and Alignment (Toe)

[gonzo]

Will installing the whiteline rear subframe bushings throw off my alignment? Just got aligned and the toe was a little off in the rear but still within factory specs. It's zero now but I'm considering installing the whiteline bushings. What are the chances it will throw off my rear toe?

Thanks.

[gonzo]

I meant the subframe inserts, KDT922:

The Whiteline KDT922 inserts (Positive Traction Kit) fill the voids of the factory bushings to dramatically reduce rear cross member misalignment & movement which allows a more positive feel from the rear end during cornering. Inserts are a cost effective upgrade, if you are looking for a stiffer press in option, consider KDT921.

[jvincent]

It might change it a little since you are unbolting the rear crossmember from the chassis.

Left and right won't change with respect to each other, so total toe will be the same, but they could change relative to the body.

[gonzo]

Since it's not messing with the toe arm I'm going with no.

[gonzo]

Originally Posted by jvincent

It might change it a little since you are unbolting the rear crossmember from the chassis.

Left and right won't change with respect to each other, so total toe will be the same, but they could change relative to the body.

Thank you! <3

[celica73]

Looking at the suspension of the BRZ, I'm inclined to say minimally at the worst.

All of the suspension arms are bolted to the subframe, so any movement in the subframe will move the suspension with it. It would be possible to "rotate" the subframe a little bit, and that would result in some rear-steer to one side or the other.


This picture also make me wonder how people are loosening the subframe and shifting it to equalize camber on an otherwise stock car. I'm just not seeing it. The only connection between the suspension and the chassis is the upper shock mount, and that has very little to do with camber (shifting the subframe will change the motion ratios a little bit, raising one side of the car and lowering the other, I guess that would help equalize camber, but to what degree???)

I did the Whiteline inserts few days ago and did notice that the rear subframe mounting holes are slotted (left-right) whereas the front are round.

[wparsons]

^^ I can see shifting the front subframe helping equalize camber, but 100% agreed on the rear.

[jvincent]

Originally Posted by celica73

All of the suspension arms are bolted to the subframe, so any movement in the subframe will move the suspension with it. It would be possible to "rotate" the subframe a little bit, and that would result in some rear-steer to one side or the other.

This was the point I was trying to make.

The rotation will cause both the left and right toe values to change, but since it is rotating, the total toe (i.e. sum of left and right) would stay the same.

[Trueweltall]

Originally Posted by celica73

Looking at the suspension of the BRZ, I'm inclined to say minimally at the worst.

All of the suspension arms are bolted to the subframe, so any movement in the subframe will move the suspension with it. It would be possible to "rotate" the subframe a little bit, and that would result in some rear-steer to one side or the other.

The rear-steer is what I am feeling after installing whiteline bushing inserts.