RRH

I was at Croft with the MLR in June, a very hot a sticky day. Net result was that the front nearside tyre decided to throw a large proportion of its tread in to the arch after only a few laps.

I decided to change front to rear in an attempt to carry on playing.

At this point I want to mention that the car usually handles very neutral. I have a coilovers on it and uprated ARB links front and rear. Geometry is set to TSL tarmac spec. I have played about with the settings of the coilovers, and apart from increasing the spring rates, which is going to happen fairly shortly, i think the car has improved no end.

Back to the tyres. My first lap out with the shagged fronts on the back the car seemed to come alive. it was turning in much more readily, and bringing the **** round like rear driver, without being dangerous. don't get me wrong, I'm not a 'showboat', the car just felt a lot better balanced.

I want to recreate this, ideally with proper tyres on it, and was wondering what the best course of action is.

I'd appreciate some advice from those of you with experience in suspension settings ~ should I alter the rear caster angle slightly, or go the other route and increase the ARB rates on the rear.


any ideas?
thanks, in anticipation,
simon

RRH

Just had an email from the extremely helpful mr croney, which has given me the information I need.

Cheers

dominicm

I have a RA which wasted it's front tyres after a few 'hot' laps around Rockingham!!

I know this was mainly due to under steer which will hopefully be cured after my visit to Power Station next Wednesday! If you were supplied with any other information that would help could you please forward it to me as I'm off to Oulton Park in a couple of weeks and don't want to suffer from to much under steer!

Cheers
Dom.
Also what pressures do you run on a dry track?

RRH

Dom, yhm

JIM THEO

So what are their recommendations about alignment settings for road use? (Send me a mail if you can't post them)
JIM

superstring

I'd be very interested to hear what Mr. Croney said about this one. An email would be very much appreciated if you can't post his comments.

Cheers, John

Whiteline Automotive

G'day everyone,

Sorry to chime in so late.

Re psoitive caster in general, in our view you can rarely have too much (within reason) particularly for spririted use. The main advantages in positive caster are (from our FAQ):

------------------------------

High levels of positive caster equate to dynamic negative camber on turn when you need it most. (Have a look at the front wheels of a Mercedes or Audi when parking.) Whiteline continues to put heavy emphasis on additional positive caster when designing new suspension packages.

Caster - "When too much caster is never enough"? – 5 reasons why.

- Maximise tyre contact patch during roll
- Improve turn-in response
- Increase directional stability
- Maximise tyre contact patch during braking and acceleration
- Improved steering feel and self-centre
- Increases dynamic negative camber (on turn)

Castor Vs camber, try castor first. Why?

- Camber doesn’t improve turn-in, positive caster does.
- Camber is not good for tyre wear.
- Camber doesn’t improve directional stability.
- Camber adversely effects braking and acceleration.
---------------------
The other important issue to keep in mind is that of static vs dynamic alignment settings. There is little point in increasing static (while stationary) positive caster if it involves fitting a much more compliant bush delivering the angular change. This could simply result in a net reduction in dynamic caster (while moving)as the chassis experiences caster "wind-back".

As our anti-lift kit and its geometry is seen as controversial by some, we have just released a bush based caster increase only solution. KCA375 is a new kit of 2x 80D bushes designed to replace the stock bushes within the factory front lower control arm rear mounts. You can see a picture at ftp://ftp.whiteline.com.au/Images/P.../KCA375_03.jpg.

This kit adds +0.5 static caster and about +1.0 dynamic through limited caster wind-back. Its ideal for anyone not wanting to run the anti-lift geometry changes while still wanting some caster improvement, or if you're looking for large overall changes for race use.

This can be used with any combination, hope this helps.

Cheers

Jim Gurieff
Whiteline

superstring

ftp://ftp.whiteline.com.au/Images/P.../KCA375_03.jpg.

This link doesn't work for me. I've tried different permutations. Jim??? Anyone??

Whiteline Automotive

Ooops!!

Try this ftp://ftp.whiteline.com.au/Images/Product/KCA375_03.jpg.

Cheers
Jim

Whiteline

ex-webby

Hi Jim

These forums are for non-commercial discussion only. If you would like to advertise, please contact me on webmaster@scoobynet.co.uk

All the best

Simon