Loose Read End

[elreg]

Hi Guys,

I have been working on a Clio 182 project track/SLS car since April, it had its first wet track time last night and we found an issue.

The rear end is very loose, both my cousin and myself both spun at various times with the rear stepping out uncontrollably.

The car is running standard suspension with Nankang NSR2’S. We have being working on getting the car reliable before carrying out any modifications etc so all bushes have been replaced with power flex items and the front CV joints were replaced. The car is stripped with a single bucket and cage fitted.

My question is with the car running standard suspension is now the time to upgrade to coilovers or do I try a rear ARB first?

We have both driven karts nationally for years and have had various track cars, we have played with tyre pressure etc but nothing really made much difference, I am aware that stiffening the rear end in the wet is the opposite of what we should do.

Open to any advise/recommendations

 

[Stefan.]

Are the rear dampers/springs in good order..?

 

[elreg]

Yes they are in good order, however the car is 16 years old and has 112k miles so upgrading to coil overs would rule that out.

 

[Bankrupt_drunk]

How wet was it? It's a light car (although still more than a go cart) and there is very little weight over the back axle. It may be some tyres with better grip in the wet might help? What geo settings are you running?
I was in the wet at bedford on monday running michelin ps3's and was mostly struggling with oversteer, but that was mainly my driving error, but i did see a few spins from people with more track focussed tyres.

 

[Bankrupt_drunk]

PS. google says a 182 weight distribution % is 65/35 front to back.

 

[plenty]

A rear ARB will make the back end more mobile, not less.

Does sound odd, though and points to a problem, perhaps worn shocks and/or bushes.

 

[JamesBryan]

Stripped on standard suspension will have caused the optimum rake angle to be altered.

With the rear end sitting higher it will have moved the weight transfer further forward, combined with old rear shocks it will only make the issue worse.

Ideally you need coilovers to correct this to get the perfect setup.

About 10mm of rake is roughly what you want.

 

[Bankrupt_drunk]

Stripped on standard suspension will have caused the optimum rake angle to be altered.

With the rear end sitting higher it will have moved the weight transfer further forward, combined with old rear shocks it will only make the issue worse.

Ideally you need coilovers to correct this to get the perfect setup.

About 10mm of rake is roughly what you want.

Really interesting. So if i remove the rear seats, tool kit and spare wheel, but have standard (cup) suspension, will i have the same issue?

 

[JamesBryan]

Really interesting. So if i remove the rear seats, tool kit and spare wheel, but have standard (cup) suspension, will i have the same issue?

Only if you have worn shocks, however you will notice the difference.

They sit ridiculously high on the rear on standard suspension when stripped out 😂

 

[Bankrupt_drunk]

My next job will be to go and measure!

 

[JamesBryan]

My next job will be to go and measure!

I saw a stripped out 172 Cup on standard suspension once and I thought it had been raised!

Could have got a dog in the rear arches 😂

 

[Kev@KAM]

In what situation is it stepping out?
If its under braking - are you driving it like a kart? The Clio will have a lot of weight transfer forward under braking with standard suspension so its possible to upset the rear in a straight line
The other potential issue is lift off oversteer. How are you applying coming off the brake and onto the accelerator. Is it snapping round mid corner?
Whats the rear toe? have you added nagative camber at the rear. If so then the rear will be toeing out more

 

[elreg]

In what situation is it stepping out?
If its under braking - are you driving it like a kart? The Clio will have a lot of weight transfer forward under braking with standard suspension so its possible to upset the rear in a straight line
The other potential issue is lift off oversteer. How are you applying coming off the brake and onto the accelerator. Is it snapping round mid corner?
Whats the rear toe? have you added nagative camber at the rear. If so then the rear will be toeing out more

We are doing track days at Knockhill and it’s at the majority of corners with any sort of direction change which is leading me to think it is the suspension, there is no suspension modifications to the car at all as I was focused on getting the engine reliable first, the brakes and tyres are now updated and next on the list is suspension

 

[elreg]

Stripped on standard suspension will have caused the optimum rake angle to be altered.

With the rear end sitting higher it will have moved the weight transfer further forward, combined with old rear shocks it will only make the issue worse.

Ideally you need coilovers to correct this to get the perfect setup.

About 10mm of rake is roughly what you want.

The rear is ridiculously high at the moment, will order the coilovers when I have done some more research, the bilstein option seems very common from what I have read on here?

 

[plenty]

You could try lowering springs first before investing in coilovers, if only to trace the cause of the oversteer issue.

On standard or even lowered shocks/springs you should be mostly understeering.

Bilsteins great on road, not so good on track. For track you need a much stiffer rear spring rate than Bilsteins. 8kg/mm or 450 lbs recommended for the rear which is double the Bilstein spring rate.

 

[elreg]

A rear ARB will make the back end more mobile, not less.

Does sound odd, though and points to a problem, perhaps worn shocks and/or bushes.

Yeah it is odd, lots of head scratching went on on Monday night, we were always planning to do coilovers once we had the car reliable so it’s the next logical step, will probably add the rear ARB in the future if required.

 

[elreg]

How wet was it? It's a light car (although still more than a go cart) and there is very little weight over the back axle. It may be some tyres with better grip in the wet might help? What geo settings are you running?
I was in the wet at bedford on monday running michelin ps3's and was mostly struggling with oversteer, but that was mainly my driving error, but i did see a few spins from people with more track focussed tyres.

It was very wet to start with and then a dry line appeared, the tyres were ok tbh and better than I expected in the wet.

 

[Martin.]

Have you checked the geo of the car?

Something may be bent on the rear and you might require shims to correct it. Ideally want between -1 and -2 degree camber and 30-40 mins toe in on the rear to scrub the tyres.

 

[elreg]

Have you checked the geo of the car?

Something may be bent on the rear and you might require shims to correct it. Ideally want between -1 and -2 degree camber and 30-40 mins toe in on the rear to scrub the tyres.

Yeah I had a geo check before I did the first track day with it last month and it came back perfect, Bilstein B14s are not available at the moment so I might be struggling to source and fit them for the 15th of August.

 

[Bankrupt_drunk]

I've got some old eibach springs you can have for free if you collect. They're not pretty, but it might help trace the issue.

 

[elreg]

I've got some old eibach springs you can have for free if you collect. They're not pretty, but it might help trace the issue.

That would be great, where are you based I’m just outside Glasgow

 

[Martin.]

Yeah I had a geo check before I did the first track day with it last month and it came back perfect, Bilstein B14s are not available at the moment so I might be struggling to source and fit them for the 15th of August.

Don't buy bilsteins for track use they are way too soft.

 

[JB21]

I'd say the main issue is the NS2R tyres presuming they're the 180 compound. They are shocking on light cars in the wet as you just can't heat into them.

Have you tried the car at a dry track day?

 

[elreg]

Don't buy bilsteins for track use they are way too soft.

What would you use? Are the Gaz ones better?

 

[elreg]

I'd say the main issue is the NS2R tyres presuming they're the 180 compound. They are shocking on light cars in the wet as you just can't heat into them.

Have you tried the car at a dry track day?

The rear rear tyres were very cold hence why we were playing with the rear pressures etc. On the previous track day it was dry for the first few hours and the rear end was loose but easily manageable.

 

[Bankrupt_drunk]

That would be great, where are you based I’m just outside Glasgow

I'm in Cambridge, so if you're passing drop me a PM....

 

[JB21]

The rear rear tyres were very cold hence why we were playing with the rear pressures etc. On the previous track day it was dry for the first few hours and the rear end was loose but easily manageable.

Sounds like tyres then. Just get a another set of cheap 15" wheels and bang some Rainsport 5 on them as they're peanuts and are very good in the wet.

 

[elreg]

Sounds like tyres then. Just get a another set of cheap 15" wheels and bang some Rainsport 5 on them as they're peanuts and are very good in the wet.

I’ve been keeping an eye for 15s but nothing has came up yet as I would like to put full slicks on 15s and keep 16s for wets.

 

[plenty]

What would you use? Are the Gaz ones better?

I’ve been using BC front and AST 4100 rears which is what my car came with when I bought it. For the road I keep the BCs up front, but swap out the rear for softer springs and standard Cup shocks.

If you buy the full BC set they come with 8 kg/mm rears which is good for track and double the OEM or Bilstein rate. Too soft springs at the rear = understeer on track, but track rear springs are too hard for the road. If buying BC new you specify the front spring rate - 7-9 kgs works well in most situations.

You really need camber bolts or adjustable top mounts for track.

 

[Martin.]

What would you use? Are the Gaz ones better?

Billies are designed for fast road use. I've been in cars with them on a track and they wallow all over the place.

GAZ you could customize a kit and basically tell them how stiff you want it. I think BCs you can do this too. I don't have any experience with either of these though, I just see them mentioned a lot on posts. I run AST 5100s on mine. Previously had AST 4100 and both are properly decent kits, not cheap though mind!

 

[JB21]

I've used the B12 prolines on track with my old Octavia VRS and they were fine, didn't find them to soft at all. Much improved over the OE set-up and very good on the road too.

If purely a track car used on the road only to commute to and from track for the money you cant beat the BC DR's with 10k front/8kg rear springs, with adjustable top mounts. Even better value if you can find a used set with minimal usage on them.

 

[Martin_172]

Cold rear tyres and shot rear dampers would be my guess. The rear is very unpredictable and horrible when the rear dampers are gone. They won't always have oil leaking down them either so don't assume they are all good because there is no sign of leaks

 

[elreg]

The pictures give an idea of how high the car is sitting currently

 

[Usr117063]

Run rear spacers

 

[David172]

The back of mine looks higher than yours and I have lowering springs! No doubt my weight transfer situation is messed up too because it's also fairly lively at the rear, but it's also fun, and I have an ARB. Coilovers are next on the list!

 

[plenty]

The pictures give an idea of how high the car is sitting currently

Looks normal.