Battling bump steer

[lybker 26 2 Cars]

This is my first to try and sort bumb steer, and hence I yet again rely on the experienced users support :-)

 

Head acke started as I relocated the steering rack about 15mm upwards, creating a lot of bump steer. Then I adjusted the wishbones connection to the hub equally 15mm downwards - seems easy enough - NOT!

 

After fiddling MANY times with different length spacers, i find best  result is 0,5 degrees difference!

 

details are as follows

damper bottomed out:                 - 5cm  -->  0,2degrees toe inwards

damper at normal rideheight:       0cm -->   0 degrees (baseline)

damper max length:                     + 5cm -->  0,5degrees toe inwards

 

my first question is - when wheels are locked, pointing straight ahead, and I move the wheels up and down - how much bumb steer tolerance is allowed?

 

secondly - if 0,5 degrees is to much, then please any good advice to reduce further is welcomed?

 

 

[welshpug 1,656]

No experience of every trying to measure or correct Bump steer myself, but the figures you have got sound quite impressive actually!

 

I have heard of cars with an S shaped curve to the bump steer profile, yours seems to be nicely dialled in at a ) shape.

[allanallen 528 2 Cars]

There’s no tolerance as such, but what you have there looks pretty good to me. A lot better than many cars from the factory. 

 

I always pay most attention to what the wheels doing in bump as through a corner the loaded wheel is obviously compressing the suspension. 

 

[Rippthrough 98]

That's not too bad, a little toe in on the inside wheel under a lot of load isn't a bad thing for something driven hard - it'll actually give you more grip.