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stability issues
simon04 - 24/7/22 at 09:53 AM

unstable on the road

Hi all.
RAW Striker.......
So about 200 miles ago i splashed out on a new set of r888's and a new quick rack 2.4 turns

All fitted and geometry done to std RAW settings

Well now its a nightmare to drive. The car seems to be very nervous on the road and almost feels that is wants to follow every undulation in the road.
If i hold the wheel and put my hands against me knees to reduce any steering input when i drive down the road it just seems to not want to drive straight as in moves to the right and left on its own which is quite un nerving

Before the tyres and rack were replaced the car was so planted i could place it anywhere at any time and be 100% confident.

It almost feels as if the car is being steered by the rear of the car now.

Rear geo was all done at the same time as the front.

All just seems most odd.

Any thoughts???

This surely cant all be in my head


SJ - 24/7/22 at 05:44 PM

Given you chnaged the rack I'd be checking if the new rack is exactly the same as the old one. If the rack is different - i.e. the inner joints aren't in the same place, then the car will steer as the suspension compresses.

When you set the geo did you check for bump steer?


simon04 - 25/7/22 at 07:18 AM

The rack is a mk2 escort brand new

It can only be fitted in one location due to mounting points on the car and rack.

If it were different length then all the rally guys and other kit car users would be having the same issue

I will check the tie rod joint us in same place though just out of interest but as above would be surprised if its different as it would cause so many people issues.

Thanks though for your suggestions


jps - 25/7/22 at 07:55 AM

Sounds very much like bump steer from the way you describe it.


simon04 - 25/7/22 at 08:18 AM

But why with the same length rack inches same place would the car suddenly develop bump steer???


SJ - 25/7/22 at 08:51 AM

I don't know Strikers well, but understand there were different uprights depending on when made. I know some cars had Mk1 Escort racks (not sure if a difference to Mk2 rack).

Are you sure you have the correct rack?


simon04 - 25/7/22 at 08:56 AM

I built the car 18 yrs ago
I used a mk2 steering rack
Recently I changed it for a brand new quick rack for a mk2
So the only difference is the ratio of the rack
Everything else remained constant


SJ - 25/7/22 at 08:58 AM

quote:
Originally posted by simon04
I built the car 18 yrs ago
I used a mk2 steering rack
Recently I changed it for a brand new quick rack for a mk2
So the only difference is the ratio of the rack
Everything else remained constant


Fair enough.

I'd be getting a laser on it and checking for bump steer then. It's pretty easy to do.

At least then you'll know if anything strange is going on


Fred W B - 25/7/22 at 11:01 AM

I bought a car that had the outside track rod ends fitted above the steering arm on one side and below it on the other. Have you got them in the right place, same as before?


simon04 - 25/7/22 at 11:23 AM

I did not remove the track rod ends from the car
I simply removed and replaced the rack

I have seen what you describe but it's not a contributing factor this time
Thanks


adithorp - 25/7/22 at 11:31 AM

Who did the geo' and have you rechecked it? Still think that's the most likely as I said on the other thread. Was the rear tracking altered or just checked?


pigeondave - 25/7/22 at 12:29 PM

Look on the JPSC site for bump steer mods

This video is also good for how to measure it.

https://youtu.be/LO07qmJ9zkk


ian locostzx9rc2 - 25/7/22 at 03:17 PM

Have you still got your old rack if so you need to check the length of the rack ball socket to ball socket as there’s lots of new racks that are slightly longer so the angle of movement has changed I’m assume you have had the tracking checked and adjusted . Finally if you gone for a quick rack ie 2.4 turns from a std rack it will feel a lot more twitchy on the road whilst hitting bumps or an uneven road anyway also what tyre presures are you running

[Edited on 25/7/22 by ian locostzx9rc2]