rear sliding around...why?

[AzNdevil]

ok so... i got the car used, around 5k km on ktec coilover shocks + ktec solid top mounts
i got new used subframe + wishbones/balljoints + steering rack bushes + new r1r 195/50/15 tires all around
tracking done twice
front, -2.2 degrees camber 10' toe out
rear, -1.4 degrees camber 0-10' toe in

front end feels really nice now but the rear is sliding around > 100 km/h
on or off throttle doesn't make that much of a difference but it feels horrible especially during mid corner when the rear end wants to come around and theres a car in front of you so i cant pull it back in line with the throttle

will a new rear anti roll bar help? or rear beam bushings? or shocks?
some friends said the anti roll bar will fix this but...shouldnt the rear end be even more loose with the bar?
thanks

 

[bozothenutter]

The stiffer the rear the more oversteer you'll get so the arb is not the answer.
Does it do it on both sides? (Ie left and right turns)
Are the schocks adjutable? Maybe set the rears to full soft and retest?

 

[AzNdevil]

hmm.... now that you mention it...
i havent really noticed it on left turns

and no shocks arent adjustable

btw both front and rear tires are running 30psi nitrogen

 

[bozothenutter]

Then it might be the left rear shock thats gone

 

[AzNdevil]

hmm...thanks will take a look at it

 

[MicKPM]

Sounds like it needs a proper setup session. What are the ride heights and cross weight percentages like?

As above, do not add a RARB as this will further exaggerate the oversteer.

 

[AzNdevil]

front ride height both sides...13cm from fender edge to rim top edge
rear ride height both sides...9cm from fender edge to rim top edge
no idea about the cross weight... proper setups shops dont really exists around here...
trial and error on "closed roads"......

unrelated question.. i got the wishbones with extra castor, the left front pushed the bumper out and i can hear it rubbing when steering is turned and accelerating out of a corner but the right side is fine, is there something i can do to sort this?

 

[MicKPM]

So you've also got the rear end lower than the front... These cars like a bit of rake (or face down, ass up as we say). This won't be helping your situation either

 

[AzNdevil]

yea the rear end is lower than the front
mick, i dont mind adjusting the height but....can you guide me to a starting point? thanks

 

[bozothenutter]

Height wheelarch to floor:
F 61cm
R 62.5

This is for a throphy...but should do just fine.

 

[MicKPM]

The above figures are pretty decent targets to start with though and not far off where I set them prior to corner weighting.

Don't forget though that the car axles *shouldn't* be set level unless you've got the driver and some fuel in the car to (CW%). Don't forget that tyre pressure will have a huge effect on your heights to so check these before setting anything.

 

[bozothenutter]

that's what I intend on doing when I finally get around to putting the rollcentre kit on....sitting in the car with half a tank measure them and set them proper.
cornerweighting is exspensive in Holland....😞

 

[AzNdevil]

good stuff thanks guys
will set it and let you know if i need further help!:smile:

 

[RS Charlie]

Silly thing to say but aren't Clios meant to run more air in the front tyres as opposed to the rears? Whilst I appreciate it is a track car I have my tyres set as per book and the handling is spot on .

 

[MicKPM]

It depends entirely on preference and conditions - That's like saying all men like women with tits (Actually, not a great example)

 

[RS Charlie]

I agree entirely with preferences and conditions. Although careful Mick, you've agreed with me . Marmite I guess is a good example .

I was wondering if the OP had ever tried the original tyre pressure settings as a benchmark and then gone from there. I would have thought that the lower pressures at the rear as per the factory would have got him some grip back and it is potentially a free fix .

 

[MicKPM]

I am not discounting the tyre pressures but from what he's said, I honestly think the biggest issue he has at the minute is incorrect ride heights/weight distribution (especially the front/rear biased)

 

[AzNdevil]

going to adjust the height and drop the rear tire pressure tomorrow...
anything over 30 is a pain the drive on road...

btw another theory is with the way i drive... im not that used to driving ff cars or short wheel based...
came from a jdm gc8 sti type r and two e36 before that

 

[AzNdevil]

ok checked rear shock its fine
was going to adjust height but the wrench i got was t he wrong size so i need to find one eventually
dropped rear pressure by 2 psi to 30/28... car drives better and a lot more stable in general but understeering in corners now