Off-Set Steering Rack Bushings

[DocB]

I am about ready to replace/upgrade the suspension and steering on an 03 Cobra maintaining the stock K-member and oil pan. Mods will include new springs front and rear (lowering about 1.5"), re-valved shocks and struts, off-set LCA bushings, bumpsteer ends on tie-rods, X2 ball joints, sway bars, sway bar bracket and bushings, sway bar end links, CC plates, and aluminum steering rack bushings.

With the above mods, I have not been able to determine weather I should use centered or off-set steering rack bushings in regards to being able to maintain the best suspension geometry for optimal alignment for OT use.

I have come up empty-handed in my research with a definitive answer, so I also called upon two trusted vendors, who have set up numerous cars, and no dice either.

For example:
MM says to use centered bushings.
Steeda says use off-set bushings.

My understanding is that if the car is lowered, the tie rod ends will come up in relation to the previous geometry, and that the stack on the stud will then lower it down to the appropriate position after bumpsteering.

So I am confused as to when which of the above rack bushings are used/required with the above mods, which are pretty common fare for this type of car and platform.

If you have installed aluminum rack bushings on a car, you thoughts, experience, and advice would be greatly appreciated.

TIA,
Bruno.....

 

[Sirl]

sent a pm.

 

[wheelhopper]

I would go with the MM aluminum bushings.

 

[KILRSVT]

I have mm bushings on my stock k member and the steering response is great.For the price there worth every penny

 

[MFE]

My understanding is that if the car is lowered, the tie rod ends will come up in relation to the previous geometry,

Yes, and when you do, the A-arm comes up the same amount, following the factory bumpsteer curve, which is reportedly pretty good. Net/net, no change in the bumpsteer curve, so no adjustments needed. It's really only when you lower the car by changing relationship between the A-arm and tie rod that you need a bumpsteer kit or relocated rack bushings. For instance if you install X2 balljoints, you change the relationship. If you move the A-arm pickup points up or down, you change the relationship. Short of that, you shouldn't need offset rack bushings, the exception being if you lower the car so much that it puts the suspension into the extreme end of its bumpsteer curve. In that case, and frankly every case where changes are needed, you're WAY better off installing and properly measuring and adjusting an actual bumpsteer-adjustable tie rod end kit, and not offset rack bushings.

That said, aluminum rack bushings will really sharpen your steering precision and response, and MM's are uniquely designed to minimize any tweaking of the rack that results from the rack not being squarely mounted.

 

[DocB]

Thanks for the in depth responses.

I will be installing MM centered rack bushings.
The front and rear will be bumpsteer adjusted.