Bump steer correction on RHD coupe

[7ish]

I'm after some ideas on how to reduce the bump steer on a right hand drive coupe with the flaming river steering rack.

I have extended the rack 26mm to align with the suspension pivots. I get this graph of bump steer:


https://i.imgur.com/tuSXLZx.jpg

After some ideas to sort the curve at full droop...

[David Williamson]

what front end parts have you got? If you have the 2 piece FFR spindles the bump steer is not noticeable when driving the car. I am not an expert and you don't have any scales on the drawing but what you have looks good.
How does it drive? My old mkll with Mustang donor parts shakes the steering wheel in you hand going over bumps but the Gen 3 Coupe with the new 2 piece spindles does not.
David W

[7ish]

Hi David, I have the spindles with the bolt on steering arm.

The vertical scale is 25mm per division, max out is 15 mm at full droop or 1.5 degrees toe out.

Theory suggests I need to lower the rack, but I have made my own mounts, and I have it as low as it will go. Still at the construction phase, so can't say how it drives.

[David Williamson]

The suspension on these cars is stiff and does not move much while you are driving. I think you will find it drives well as the suspension travel will be mostly in the linear area and never gets anywhere near full droop.
What ride height have you set it at? I run mine at 3.5 front 3.75 rear.
David W

[7ish]

Thanks. Ride height set as standard 4.5".

I'm sure you are right.. it will drive well.

The issue is NZ certification requires bump steer to be less than 10mm throughout the entire travel. I could always put a shorter shock on for the test...

[David Williamson]

moving the coilovers to the upper mount location might give you the result you need to pass the test? good luck with it, they are cool cars
David W