Rear Camber and GEO set up

[Machine monkey]

First of all i dont want sick camber bruv!! But what if any are the negative handling features negative camber might cause at the rear? I am aware it might scrub out the inner of the wheel quicker.And i really dont want my wheels sticking in at stupid angles!! I have sorted my rubbing problems almost but i think .5 or 1 degree extra might possibly make a difference?

Also this has been done to death but can i just confirm a few things. I have read that should maybe get my car set up to M specification? With maybe a little more tow in say 1 degree and that i should pull the camber pins at the front to allow a little extra there as well????? My car is a weekend toy so tyre where is not a huge concern (although they are expensive and dont want new ones every 5k miles!!) I want my car to be alive and engaging but still stable at motorway speeds?

If it makes any difference i have (will have) All new bushes front and back spax rsx coilovers the bushes are a mix of powerflex and Meyle HD. M anti roll bar front and hopefully an adjustable eibach rear. And a LSD :evil: Also where do i go any companies local to Oxford that i should use? I have a guy that always dose my tyres and the seem good. They have a full computer laser set up but its not Hunter???

Thanks for any advice and help

 

[glnk]

More negative camber on the rear is less traction and less straight line stability. The tire-road contact patch gets smaller

 

[Babw]

Ideally you need to measure tire temperature across the width of the tread to determine how much camber you're running, the aim of increasing static negative camber is to counteract positive created dynamically.

Most manufacturers aim for about -0.5 deg negative dynamically which could in the region of -1.5 to -2.5 on factory cars depending on spring rates, tyres and suspension design.

Excessive negative camber doesn't really affect stability in a straight line but traction and braking in a straight line. Especially important in wet weather.

Toe affects tyre wear and stability more. I would start with a touch toe in and go from there.

 

[Beetlegav]

Had my wheel alignment sorted last week. Feels loads better!

Bit daft of me though, I'm now buying coilovers :/ haha.

Do your rear wheels catch on your arch liner, my et40 rear wheels spaced 15mm seem to catch when I have the missus in the passenger seat (I blame her weight....) and it's really irritating! Even with the camber maxed out it still catches but only on passenger side.

 

[glnk]

Ideally you need to measure tire temperature across the width of the tread to determine how much camber you're running, the aim of increasing static negative camber is to counteract positive created dynamically.

When racing yes. But racers go through a set of tires in one session. Temperature also depends if you just had to corner really hard. Obviously you would want close to an even spread on tire temperature. The hottest temperature should be on the inside closely followed by the middle then outside temperature. Thread wear is also to be looked at. Now, on normal street driving an ideal camber setup for the racetrack would not be ideal because it would mean the tire wears a lot on the inside and not so much on the outside because you dont take corners at the limit all day long on public roads

 

[Babw]

Ideally you need to measure tire temperature across the width of the tread to determine how much camber you're running, the aim of increasing static negative camber is to counteract positive created dynamically.

When racing yes. But racers go through a set of tires in one session. Temperature also depends if you just had to corner really hard. Obviously you would want close to an even spread on tire temperature. The hottest temperature should be on the inside closely followed by the middle then outside temperature. Thread wear is also to be looked at. Now, on normal street driving an ideal camber setup for the racetrack would not be ideal because it would mean the tire wears a lot on the inside and not so much on the outside because you dont take corners at the limit all day long on public roads

So lets agree that the main aim of camber on a road car is for even tire wear.

The OP states his car is for weekend/fun use so I'm assuming he would not mind a slight trade off in tire wear for a better turn in. However way you look at it increasing negative camber will increase his turn in as a result of camber thrust. Unless you're going to extremes it will not affect his straight line stability but it will affect his traction hence why winter tires should ideally have a new alignment to essentially equilibrate the increase in pliability of the tire and thickness of rubber as well as to counteract the less traction caused by the conditions.

I guess the only time negative camber will cause destabilisation is when a front wheel loses traction due to a rough surface and the camber thrust from the opposing wheel acts solely on the car.

I've had numerous BMW's now and lack of negative camber + a incorrect toe setting will do far more damage to the handling/tire wear than running too much camber. The toe and camber settings set by default are to allow the car to have a "safe" transition from understeer to oversteer. If you increase the negative camber and start heading towards toe out the transition will be more aggressive so do be careful.

I'm going through the process on my Z4 at the moment and fortunately I have camber plates and adjustable arms at the back along with friends with a hunter machine and experience setting up R8 LMS ultras for 24 hour racing so I've picked up a few things from him.

When I went through the process on my M3 it was a gradual transition from stock towards a more race orientated setup, if I had gone straight from factory to the current setup it would have ended in tears!

 

[Machine monkey]

Thanks for the responses guys. I will have a good read and digest at lunch

 

[spokes]

Hi Mat - I have been following thoughts on set up with great interest and a bit like you I am still taking in all the info.

I don't know of anyone local but I did take my Westfield to Northampton Motorsport and they transformed the handling. They have lots of experience and are more than happy to advise on different set ups. They have Hunter kit.

Might be worth a thought.

http://www.northamptonmotorsport.com/default.asp?id=20

 

[Machine monkey]

Thanks spokes it might be a bit to far but I will give them a call