Track car alignment setup help

[sjw185]

looking for some help with alignment on track car.
Not had any issues on track but driving to the track on normal roads with uneven surfaces the rear feels loose?
Almost like a rear bump steer kinda feeling.
Rear subframe and wishbones are polybushed with AK(verkline) tie rods and top mounts whiteline RARB at middle setting.
Also have 20mm spacers at the rear and 15mm front.
Have checked all bolts but everything looks good.
Was thinking to try and get rear close to stock as possible and see how that feels.
Had a read through below thread and there are a few different setting for rear toe.
Any suggestions would be a help
Thanks

https://www.s2forum.com/forum/technical/suspension-steering/75256-track-day-suspension-geometry

Alignment.jpg

[Lago Blue]

Hi sjw185,

When you have time:

Any news or further thoughts here sir? Any mechanical faults found since? This is a B3 type (Mac. struts on rear) car, correct?

Are you driving straight or cornering when this "rear feels loose" occurs? Are you steady on the gas throughout?

Is camber out all round due to less than stock spring height? If yes, could that possibly be a source of your "rear bump-steer...feeling"?

Please describe your springs and dampers.

Perhaps some of the more experienced folks will pipe in?

Cheers.

[Error404]

Reduce the rear ARB a little and see how that feels.

[Rusty]

2+ degrees of camber is going to do that a bit.

I have 2.5 up front and reduced the rear to 1.25, as it improves the balance.

I have a 25mm rear bar, which is nice.

it doesn't track too badly, maybe one of the bushes is worn?

[Error404]

Car is stripped out so rear end is light

[sjw185]

Thanks for replys everyone.

Yes its a 3b and the unnerving wobble/ floaty feeling is in a straight line when steady motorway driving.
Running KW V1s
Tried to pay attention last time driving home to see if it occurred in the same road area as before also intentionally tried to hit small undulations and cats eyes to see if I could replicate it but no joy?

I removed the welded in rear strut brace as the brackets were stopping the top mounts from sitting flat.
Tyres were quite worn on the inside down to legal mark so I had fitted new Federal 595s and dropped the rear by 10mm.
Was booked on to another track day on the 21st of March but had to cancel as I hurt my back and couldn't sit in my seat.
Now since the lock down not managed any tests.

Rear strut brace removal before and after

rear strut brace.jpg

Rear drop 10mm before and after

rear before and after 2.jpg

[sjw185]

Car is stripped out so rear end is light

Thinking along those lines when I have felt the issue its been returning from track day with low fuel.

[sjw185]

Check out the rear toe in this picture just looks odd

IMG_9527.JPG

[Error404]

That’s not right, I expect ball joint has slipped. Quite common, I have found mine can slip under load with warm sticky tyres or riding the kerbs

[sjw185]

That’s not right, I expect ball joint has slipped. Quite common, I have found mine can slip under load with warm sticky tyres or riding the kerbs

You thinking tie rods have spun throwing out toe?
Notice the locking nuts are hard to access on the subframe side.
Think I should remove the tie rod for locking off in the vice after setting up or modify subframe to allow better access to the locknut.
Will maybe have a go at the alignment with the string to see if its shifted.

IMG_8884.jpg

[LHD_Kid]

I think he means the bottom ball joint may have slipped on the wishbone.....

[sjw185]

I think he means the bottom ball joint may have slipped on the wishbone.....

Makes a lot of sense it definitely bites in hard powering out of comers