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unstable on the road
simon04 - 24/7/22 at 09:47 AM

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


David Jenkins - 24/7/22 at 09:55 AM

Have you checked your ride height front and back?

When mine was first built the front of the chassis was higher than the back, and it was a pig to drive (much as you describe), especially at speed. Adjusted everything so that the rear of the chassis was an inch or so higher than the front and everything calmed down.

I'd check your tracking too - toe-out can make the car 'exciting' to drive - twitchy and unpleasant.

Saying all that - quick racks do make the car twitchy, and I reverted to a medium-speed one.


perksy - 24/7/22 at 09:57 AM

As Above

Plus what tyre pressures are you using?


A well set-up Striker will out handle most things

[Edited on 24/7/22 by perksy]


jacko - 24/7/22 at 10:35 AM

Tyres on the right way round ?


simon04 - 24/7/22 at 11:40 AM

Thanks for all the replies.
Yes ride height checked and matches when I built it 18 yrs ago
Tyres on right way round
Tracking set and Camber set to how Raw describe in build manual.
Tyre pressures at moment f21 r20

The car was awsome before the tyres and rack
I put r888 on because I wanted it to be even better than before when I had avon zv whatevers which I put on the car 18 yrs ago
I knew the rack may make it a little different but it's just horrid atvthe moment
I rekon a fully loaded Citroën Picasso could have me at the moment.
It's all about confidence and atvthe moment it just seems to wander all over the road.
It's never done it before
So. Back to you guys for more suggestions please .


perksy - 24/7/22 at 11:47 AM

What toe setting are you using on the front and rear ?


simon04 - 24/7/22 at 12:13 PM

F 1.5. To 1.75 neg Camber
0 toe or 1deg toe in.
Raw does suggest 1mm toe out but that made it really horrid and normally toe out is more track orientated where as road tends to sit parallel or toe in to take the twitchy out of the car

R 0 Camber
2 to 4mm toe in


Jaymaxi - 24/7/22 at 12:48 PM

The setting you have seem reasonable,but bearing in mind the car lightness, chassis length and lack of rubbers in suspension it may be one for the Striker boys, can you find out what was changed when you got the tracking done, maybe your back trackings a little much and try reduce front toe in by a few minutes, if it was mine I'd put it on a 4 wheel track bench and make sure all is set thue, also pump tyres a bit for setting, John


theconrodkid - 24/7/22 at 02:03 PM

sounds a lot like tyres, tram lining is the tech term, are they the same size tyres as before ?, can you borrow another set of wheel and see it there is a difference.


simon04 - 24/7/22 at 02:10 PM

Yes I agree
That's exactly how I would describe it.
Tyres are exactly same size as before
185/60x14
I can't remember what pressures I ran before so I think the next trial will be to drop a load out and see what happens I guess
It's just so frustrating when before 2 simple changes of rack and tryes it was an awsome weapon


adithorp - 24/7/22 at 03:59 PM

I'd get the settings re-checked. There 888s shouldn't cause issues ( lots of strikers on them) but they might accentuate them. The quick rack will make it feel more twitchy until you get used to it but that shouldn't take long and again only accentuate what's there already.
Which leaves settings... 2-4mm on the rear sound quite a range; Which end of that is it set at? (I'm running just 1mm on my Fury)


Myke 2463 - 24/7/22 at 04:03 PM

I am not a striker owner. From what i understand from mates who use R888 they run 16 to 18 in tyres with zero toe to the rear. Remember you probably have much more grip than before and they are fighting to use that grip hence being unstable. Do not run toe out on the rear, from personal experience 0 to 0.5 is ok on a 7 style car. Good luck.


ReMan - 24/7/22 at 07:05 PM

Have you actually given time for the tyres to scrub up properly and loose the release chemicals etc?
Wont notice it an a std tin top but on such a light car you will


peter030371 - 24/7/22 at 09:15 PM

Assume it's IRS?

I run the same tyres but 13" and find 17-18psi (cold) is about right. Over 20psi cold is horrible.

I will try and dig my current settings out as mine is not twitchy at all.


snapper - 24/7/22 at 10:02 PM

quote:
Originally posted by peter030371
Assume it's IRS?

I run the same tyres but 13" and find 17-18psi (cold) is about right. Over 20psi cold is horrible.

I will try and dig my current settings out as mine is not twitchy at all.


I was going to say the 21-20 seemed high for a very light car so try the above, also invest in a cheap laser temp gauge and check temps across the width, you want even across the width after a spirited run


simon04 - 25/7/22 at 07:13 AM

Hi. Yes it's irs.
As I've said before changing tyres and rack it was super planted and a dream to drive.

I'm leaning towards tyre pressures now.

Going to go with 18 and see what its like.

The settings RAW state on their spec sheet (or did when in business) are how the car is set up which is why I'm scratching my head

Jeremy Bulmer has confirmed that the rack will make it much
More twitchy on the road but that doesn't explain the tram lining
Literally with no movement on the steering wheel the car can move from hedge to white line on its own which is the scary bit.

Thanks to everyone that has suggested tips and tricks so far
More always welcome.....


peter030371 - 25/7/22 at 09:28 AM

quote:
Originally posted by simon04
Literally with no movement on the steering wheel the car can move from hedge to white line on its own which is the scary bit.



Sounds more like bump steer to me then. Relatively easy enough to check yourself with a few basic tools, fixing it is a little more complex as you need to move the steering rack mounts a little but others have done it on Striker/Furry chassis.

I am sure if you google bump steer you will find loads of info on it.


ReMan - 25/7/22 at 09:35 AM

quote:
Originally posted by ReMan
Have you actually given time for the tyres to scrub up properly and loose the release chemicals etc?
Wont notice it an a std tin top but on such a light car you will


Just to add, for me, without any of the other complications, what your describing sounds like the same as I have had with not enough toe in at the front.


simon04 - 25/7/22 at 09:49 AM

Why would it suddenly develop bump steer after 18 yrs.
All I did was swap the rack for an identical one but with a different ratio
The length of everything else is identical


contaminated - 25/7/22 at 12:44 PM

I have to say, if I ran my R888's over 20 psi I'd be all over the place. 2 psi makes a massive difference on mine. No higher than 18 for me.


simon04 - 25/7/22 at 02:00 PM

I've done 3 test runs now
Down to 17psi on the fronts and rears and it's more stable
Clearly was suffering from tram lining
Do you run your rears same higher or lower than fronts

Cheers


nick205 - 25/7/22 at 03:41 PM

On my MK Indy (2.0 Pinto, Type 9 gearbox and 15" wheels) I ran between 16-18psi cold. Any higher and the car was twitchy.

Even on 13" wheels where you'll have more air volume in the tyres, tyre pressure is massively important!


peter030371 - 25/7/22 at 03:52 PM

quote:
Originally posted by simon04
Why would it suddenly develop bump steer after 18 yrs.
All I did was swap the rack for an identical one but with a different ratio
The length of everything else is identical


I can only speak from my experience. 'Standard' ratio MKII escort rack next to a quick rack from RD, supposed to be Escort MKII, and the length of the rack body was different by 5-6mm each side...hardly noticeable to the eye but checked and checked again and it was different. I only fitted the quick rack so no idea how much difference it would of made but I am sure it would make some difference

Its easy to measure/check so why not? If no bump steer then you can cross that off and work on a shorter list of reasons


contaminated - 26/7/22 at 08:40 AM

quote:
Originally posted by simon04

Do you run your rears same higher or lower than fronts

Cheers


Same back and front for me.


simon04 - 26/7/22 at 10:13 AM

I'm just in the stage of dabling with that
At the moment same f and r
But over bumps the rear jinks to the side as if tyre walls are flexing.


Mr Whippy - 28/7/22 at 05:56 AM

Although you say the rack is identical it does sound like bump steer, coupled with the reduced leverage from the steering gear ratio. I'd simply swap back the old rack, should take 30 minutes at most... Remember to change only one thing at a time so you can see the effects.