Si2k

Since getting my alignment done after fitting Konis and with Standard (I think) springs I have noticed quite large bump steer effect at the back when I hit a divot/pothole in the road on a single side of the car.

As the suspension under goes bumper it feels lie it is causing Toe in on that wheel causing the rear to yaw, i dont need to adjust the steering as it soon rebounds and straightens up, however it is a bit unsettling!

The car is still at stock ride height.

Any thoughts on how I can remove this, is it a function of running such minimal rear toe?

Ultra_Nexus

Have you lowered the car?

Si2k

No was tempted to go to the lower perch on the Konis for a small drop but left it as it was. Ride height is pretty much the same as it was before the suspension modifications.

Tyre pressures are all correct at 32psi all around.

I only notice it on the back roads or broken tarmac, on smooth stuff it's fine.

lovegroova

I'm experiencing a similar effect with my new coilovers, and it's worse if I soften the rear damper settings.

It's not down to the rear toe, as I have 30' each side.

It also has to be said that my tyres are not in the best condition.

The ride height has been reduced a small amount. I think I'll get it booked in at WiM to get the ride heights sorted out properly.

Si2k

Hmm interesting then if you say it's not rear toe.

Maybe its a result of poly bushes removing rear compliance. My rear lower arm is poly bushed and so is the track control arm. Upper wishbones are OEM.

What bushes are on yours Simon?

lovegroova

I'm not entirely sure it's rear toe, but given we both have the problem and have toe settings which are quite different, I suspect it's not that.

The control arms are poly bushed, but have been for a long time allied to stock suspension, and whilst there was an element of traditional S2000 rear skip, it's become much more pronounced with the new coilovers.

I suspect it's a combination of poor tyre condition and ride height.

punchdrunk

what tyre sizes are you running?

I don't get bump steer on mine with my 215/255 set up. The bracing helps.

lovegroova

OEM 16s.

Si2k

225 rear. I doubt its anything to do with bracing, it feels like a definate toe angle change which I have never noticed - certainly not to this extent) in the 4yrs of driving the car before.

I have had the same type of tyres on for the last 3 years (RE050As).

The only significant difference is the Geo, the Konis and the polybushes. One of those must be a factor, I'm not sure on the cambers effect on bump steer, I guess camber thrust could be a factor when you get some bump induced camber added.

lovegroova

I'm pretty much in the same boat, although it's just the coilover/ride height change for me.