Rear toe

[KenH]

I have been following all the posts on here about rear toe. At the moment I have 1 mm toe in on near side and 3mm toe out on offside. Camber settings are -1.5 and -1.3 respectively on newly fitted Eibach Pro springs.

From reading the posts there is quite a variation of opinion about what settings the rear toe should be at with most suggesting rear toe out islikely to lead to a very loose rear end.


Some one very kindly passed me the renault Technical note 3676a for CB1N (Clio Cup) which quotes rear toe as -3.8 + or- - 3.6mm ( for two wheels). This suggests that the standard car runs a lot of toe out .

Does anyone else with a Cup run this much toe out?

 

[Tony Hunter]

The standard car will not run toe out, It's been bent at some time or other. Rear beam is made of cheese and doesn't take much to knock it out.

 

[KenH]

Sorry Tony, my original post should have read 3mm toe in on the offside not toe out. (i'm just obsessed with toe out at the moment). Are you saying the Cup has never been manufactured with toe out or just that it won't work with toe out?

If the Renault Technical note is wrong, what are the correct, from the factory, settings?

I have, btw, set the front to 1mm out based on your recommendation in an earlier thread so certainly will be guided by you on the rear.

Thanks

 

[KenH]

If anyone is interested hear is a link to the Technical note.

http://www.renaultalpineownersclub.com/Workshop Manual/Clio/3676A.pdf

I should add that it was the lads at Chase Racing who put me on to this. I just didn't know how to up load a PDF file so I found a link to the same document.

 

[MG cup]

You should never run different amounts of toe in/out from side to side on the car. Different from front to back maybe. Do you know what n/s and o/s mean. I think you have your numbers wrong unless it's had a bash

 

[KenH]

You should never run different amounts of toe in/out from side to side on the car. Different from front to back maybe. Do you know what n/s and o/s mean. I think you have your numbers wrong unless it's had a bash

I am not intentionally running different toe side to side. I took my car to have it checked after fitting Eibach springs and camber bolts. I got the front sorted but now I know I need to sort the rear and this is why I am seeking some advice before doing so. My settings are a long way from what Renault appear to be suggesting but Renault's settings for the rear also seem to be different to what people on this forum run. Also they quote a massive tolerance range which suggest you can run anything from 0.2 to 7.4 mm toe out!

Perhaps you will enlighten me what it is about n/s and o/s that I don't understand, please. Any constructive comments welcomed.

 

[Tony Hunter]

What size wheels are you running?

If on 15s, a rough guide is.

1deg camber shim = 3mm

I only know this as we have just had ours done, and calculations from both Pure Motorsport and Ktec came to this conclusion.

We had to put 1deg on one side and .5 deg on the other, this was to square the rear up with a little toe out.

No doubt somebody will say that it's wrong, but the car has been on a machine and is now perfect.

 

[MG cup]

Well nearside is passengers side and offside is drivers side in the uk. Originally reading your post I thought you had that mixed up for front and back.

Most front wheel drive cars run parallel for front and back on the road. In front drive cars, toe in on front is used so when the car accelerates the front wheels are pulled outward to parralel. The opposite for rear drive the rear wheels are set with some toe out so when the car pushes itself forward the wheels fold in to parallel.

Everything is specific to manufactures as whether they use machpherson strut or multi link design etc etc, they all act differently.

By the sound of it in your situation you have had a knock to the axle with toe in on both sides, that's the most common fault with a knock, with your original description I thought your axle may have moved and you could still equall that difference you have up to an extent as there is some movement available in the back axle where it bolts to car, six bolts not the swivel bolts either side of the car. Other than that new axle.

And as far as the large tolerance that is just to cover there arse so they can sell mass produced cars with varying shapes and sizes.

 

[Tony Hunter]

Most production fwd cars will run with toe in. (safe)

 

[MG cup]

Agreed safer but if you read a chart from the likes of Kwik fit etc.... I know, there rough but most cars on these types of charts are parallel. Not all though.

 

[MG cup]

Have you ever played with the movement on the axle tony or just shimmed to suit. Ithere must be a good 5mm of adjustment in there measured from the front or rear of wheel rim.

 

[st3ve]

I've always had the belief that with a Renaultsport Clio at least it should be toeing out slightly on the front and toeing in slightly on the rear as standard.

 

[Tony Hunter]

Have you ever played with the movement on the axle tony or just shimmed to suit. Ithere must be a good 5mm of adjustment in there measured from the front or rear of wheel rim.

Oh yes,lol.

We loosened it off, big bar etc.

But when we welded the PM strengthening kit, it must have moved slightly (lots of welding and heat going on).

 

[KenH]

What size wheels are you running?

If on 15s, a rough guide is.

1deg camber shim = 3mm

I only know this as we have just had ours done, and calculations from both Pure Motorsport and Ktec came to this conclusion.

We had to put 1deg on one side and .5 deg on the other, this was to square the rear up with a little toe out.

No doubt somebody will say that it's wrong, but the car has been on a machine and is now perfect.

Alignment was done on 16 inch rims but we also run 15 inch rims on track.

What constitutes a little toe out? Presumably less than the Renault spec I quoted.

 

[st3ve]

Half a degree I guess.

 

[MG cup]

I'm not sure of Clios exact road settings but as a rule of thumb I've found most fwd parralel on the road. In racing I know a lot of guys in fwd cars like parallel axle for a planted feel and front toe out around 30 minutes depending on power.

 

[Tony Hunter]

Couple of mm, Makes the car turn in better.

Downside, unstable under braking and can make the rear of the car, as we say, lively.

 

[MG cup]

Oh yes,lol.

We loosened it off, big bar etc.

But when we welded the PM strengthening kit, it must have moved slightly (lots of welding and heat going on).

Saying that after fitting my strengthening kit my axle sits a rocks slightly when on a flat surface, should have allowed time Cool and stitch welded etc but aswell, nothing a few big bars and some shims shouldn't cure.

 

[KenH]

I'm not sure of Clios exact road settings but as a rule of thumb I've found most fwd parralel on the road. In racing I know a lot of guys in fwd cars like parallel axle for a planted feel and front toe out around 30 minutes depending on power.

The car although virtually standard is primarily for track use . I only live 3 miles from our local circuit ( Blyton Park) so only road outings it gets are for fuel and maintenance, hence I had been looking to optimise settings for track use so still veering towards a bit of rear toe out. I will find out on saturday if I have gone too far.

 

[MG cup]

You might find it okay but with around 1 deg toe in and 20 minutes on the other side from what tony has said you might find it steering from the rear under braking but I can't see you noticing much just springs and an otherwise standard car.

You mentioned 15" & 16 is that larger for road and smaller for track, if your swapping that's going to throw out your setup.

 

[Tony Hunter]

The calculations we had done were for 15s, that's why I asked. It will make a difference.

Our car is so touchy to any changes that we make.

 

[KenH]

You mentioned 15" & 16 is that larger for road and smaller for track, if your swapping that's going to throw out your setup.

That's thrown me. I'm running 16inch (205/45/16) for road and 15 inch (195/50/15) for track. The measurements quoted and front alignment were done on the road tyres. So what will happen when I switch to 15 inch rims for the track? The circumference of the track tyre is 180 and road 186 cm ( a lot more tread on the road tyre). Remember please I am only interested in the track set up. Yes, someone will no doubt say I should have had it aligned on the track tyres but they are too worn to take on the road.

 

[MG cup]

That's what I'm getting at, the difference in diameter. Your 16s have a diameter Of 591mm and 15s is 576mm. At around 2.5% it's not a lot of difference but will alter settings, if your spending money you should have setup on 15s a d switched to 16's for road driving. I'm sure you know but altering ride height, camber or caster then tracking must always be done after.

 

[KenH]

Finally got the car back together following the fitting of rear camber adjusters. What should be a couple of hours work turned into a much bigger job. When removing the brake discs neither would come off without leaving half the bearings still attached to the stub. So either fit new bearings or new rear discs complete with bearings. Before I could progress I had to get the bearings off the stubs. One came away after several minutes with a hammer but the other one didn't. Having exhausted my limited skills I took it to a local garage who cut it off. The only problem with that was they also cut a couple of chunks out the stub, including one where the shaft of the stub joins the back plate. They said it would be fine and considerately didn't charge me. Our experience of stub axles snapping on karts told me to err on the side of caution and fortunately Renparts who are in my area had a used one in stock. After variuos attempts to remove the outer part of the bearing from the discs I gave up and bought some new discs from my local Renault dealer who was cheaper than the motor factors I tried.

As part of sourcing the new discs I established that a spacer should be fitted between the back of the bearing in the disc and the back of the stub. The garage who fitted new bearings just before I bought the car had obviously not thought these were necessary and this I suspect is why the bearings were so tight on the stub.

Once I got all the right bits it went back together surprisingly well and as an added bonus the rear toe has gone from 4mm in to 0.25mm in overall. I don't know if this is anything to do with fitting the camber shims or if just taking it all to bits and putting it back together has sorted the problem.

I did experiment with some home made shims to adjust the toe but for the adjustment I was looking for they have to be very thin indeed. I did find that the reassembly process could make up to 2 mm difference across the two wheels. Maybe something as simple as the wheel seating differently or a bit of rust on the hub can give spurious toe readings.

No wonder Renault quote a tolerance of +/- 3.6mm on rear toe!

On track tomorrow at Blyton Park to try the changes out.

Thanks to everyone for their input.

 

[Tony Hunter]

So what shims did you put in to rectify it.?

 

[KenH]

So what shims did you put in to rectify it.?

I used Eibach 1 degree shims to increase the negative camber but abandoned the shims I had made myself to adjust toe as I ended up with about 10mm toe out. With my driving skills I thought that might be a bit dangerous. As luck would have it when I just had the Eibach shims in for the camber it turned out ok.

 

[Tony Hunter]

Strange.