This is the question I have. Im puting on the eibach pro-system plus kit on my 03 gt which includes shocks struts springs and front and rear swaybars. Along with MM CC plates. I wanted to change out the rack bushings to get better steering response. So I did not know which ones to get steel offset or steel regular bushings.
Steeda insisted on installing offfset bushings while Maximum motorsports said not to do so, and said offset bushings would create more bumpsteer on a stock k-member. I pulled this info right off mm web page. What do you guys think? check this out.
"There is a myth that the tie rod should be kept parallel to
the ground to avoid bumpsteer. THIS IS NOT TRUE! What
IS required, is that the tie rod be kept parallel to the lower
control arm so that as the suspension moves, the arc of
the ball joint and the arc of the tie rod end do not cause
any steering input to the spindle. As you lower your car,
the tie rod end and the lower control arm move together,
staying parallel. If you install offset rack bushings on a
stock geometry K-member, you are making the tie rod end
and the lower control arm NOT parallel. You will actually
CREATE bumpsteer by installing offset rack bushings on a
stock K-member.
Ford engineers have actually done a very good job at
designing a low level of bumpsteer for daily driven cars.
Specifically, Ford has designed the bumpsteer to toe out
the front wheels under bump. This is a roll understeer
condition; the outside loaded tire will turn to the outside of
a corner as the body rolls. This condition is designed by
Ford by positioning the tie rod end slightly low relative to
the steering rack.
Increasing caster raises the tie rod end relative to the
steering rack. Increasing caster up to half of the
adjustment range with our Caster/Camber Plates will
actually HELP bumpsteer and help performance by
reducing roll understeer. If you increase caster beyond half
of the adjustment range, the bumpsteer curve will shift
toward toe IN under bump, or a roll-oversteer condition. In
this case, it is beneficial to raise the rack, but only by
about 1/10 of an inch. Offset rack bushings raise the rack
far too much. The best solution is to lower the tie rod end
using a bumpsteer kit (MMTR-3,-4). See our test results in
the July 1993 issue of Super Ford for details.
Competition cars using stock K-member geometry will
also benefit from an adjustable tie rod end kit (MMTR-3,-
4). These kits provide an assortment of spacers in .015"
increments to best position a rod end at exactly the
correct height; thus taking into account suspension
geometry tolerances.
Offset rack bushings DO have a purpose and may be
beneficial if you have raised your inner control arm pivots
using an aftermarket K-member. In this case, raising the
rack will help match the geometry of the raised inner
control arm pivots. If you do use offset rack bushings, be
sure to only use aluminum bushings - polyurethane offset
bushings do not work. The urethane has too much “give”,
and therefore it is impossible to get the rack mounting
bolts tight enough to prevent the bushings from rotating
during hard cornering."
Steeda insisted on installing offfset bushings while Maximum motorsports said not to do so, and said offset bushings would create more bumpsteer on a stock k-member. I pulled this info right off mm web page. What do you guys think? check this out.
"There is a myth that the tie rod should be kept parallel to
the ground to avoid bumpsteer. THIS IS NOT TRUE! What
IS required, is that the tie rod be kept parallel to the lower
control arm so that as the suspension moves, the arc of
the ball joint and the arc of the tie rod end do not cause
any steering input to the spindle. As you lower your car,
the tie rod end and the lower control arm move together,
staying parallel. If you install offset rack bushings on a
stock geometry K-member, you are making the tie rod end
and the lower control arm NOT parallel. You will actually
CREATE bumpsteer by installing offset rack bushings on a
stock K-member.
Ford engineers have actually done a very good job at
designing a low level of bumpsteer for daily driven cars.
Specifically, Ford has designed the bumpsteer to toe out
the front wheels under bump. This is a roll understeer
condition; the outside loaded tire will turn to the outside of
a corner as the body rolls. This condition is designed by
Ford by positioning the tie rod end slightly low relative to
the steering rack.
Increasing caster raises the tie rod end relative to the
steering rack. Increasing caster up to half of the
adjustment range with our Caster/Camber Plates will
actually HELP bumpsteer and help performance by
reducing roll understeer. If you increase caster beyond half
of the adjustment range, the bumpsteer curve will shift
toward toe IN under bump, or a roll-oversteer condition. In
this case, it is beneficial to raise the rack, but only by
about 1/10 of an inch. Offset rack bushings raise the rack
far too much. The best solution is to lower the tie rod end
using a bumpsteer kit (MMTR-3,-4). See our test results in
the July 1993 issue of Super Ford for details.
Competition cars using stock K-member geometry will
also benefit from an adjustable tie rod end kit (MMTR-3,-
4). These kits provide an assortment of spacers in .015"
increments to best position a rod end at exactly the
correct height; thus taking into account suspension
geometry tolerances.
Offset rack bushings DO have a purpose and may be
beneficial if you have raised your inner control arm pivots
using an aftermarket K-member. In this case, raising the
rack will help match the geometry of the raised inner
control arm pivots. If you do use offset rack bushings, be
sure to only use aluminum bushings - polyurethane offset
bushings do not work. The urethane has too much “give”,
and therefore it is impossible to get the rack mounting
bolts tight enough to prevent the bushings from rotating
during hard cornering."