The Rig

iTrader: (13)

My classic suffers quite bad from bump steer,not sure if the rear whiteline 24mm antirollbar has contributed to it, i have it set to the stiffest setting as harsh driving round bends the front drifts out, anyhoo, car is lowered/fitted with showa/kyb shocks with progressive springs, standard front ARB

Was looking to get the antibumpsteer balljoints and also the whiteline power steering rack bushes to help

Anybody fitted the balljoints and rack bushes and did they help ?

cheers

Vxr2010

Try setting rear arb to mid setting and get a full tracking set up done on the car see if it helps

RetroPug

Bumpsteer (if that is genuinely what you're experiencing) is pure kinematics, and nothing to do with compliance, so rollbar stiffness won't affect it. It is possible to DIY measure your bumpsteer curves at home but it's a pain.

It could be understeer, or it could be that you've changed the geometry a lot when lowering and it is bumpsteer.

Jonny Cut Corners

As Retropug says, lowering any car can/will give bump steer. The more you drop it the worse it'll be. In simplistic terms, its to do with the difference in angle between the control arms and tie rods.
But you can get roll centre correction ball joints from whileline and possibly fuji racing (import car parts)

The Rig

iTrader: (13)

Cheers guys, its definitely bump steer, any bump in the road causes slight left n right movement of the wheel needing constant minor correction if along a road with lots of bumps etc ( most roads round here ! )

I did have the whiteline Rear ARB set to the middle , then I tried the furthest setting, this was a mistake, made the car much worse at higher speed, so I have now resulted in the softest setting and the bumpsteer is better but still there so have just ordered the whiteline correction kit ( tie rods and balljoints ) along with a set of whiteline steering rack bushes.

Im hoping all these bits fitted plus another alignment should remove most of the bumpsteer being experienced, fingers crossed

The car is quite low so putting it down to the wishbone/steering rack being too straight and needing some angle put back into them

cheers

Jonny Cut Corners

Let us know how you get on.
I think the whiteline kit should all but solve the issue. It improved my track car, but I never felt masses of bump steer tbh.

JDM_Stig

iTrader: (3)

+2

2pot

iTrader: (3)

Failing track rod end would also cause bump steer. As has been said previously, a roll bar won't.
Your softening of the rear bar is bringing independence/grip back to the rear suspension.