Help setting car up for the track ?

[adam_r]

Hello guys

 

A good friend and myself got in to the track day scene since then we have done a few circuits.. cadwell being the latest attempt

 

we are currently running a rover 600 2.0 turbo which is stripped out etc.

 

At cadwell we both noticed that the tyres gripped, but seemed to be unpredictable when reaching their grip limit (hard cornering). On further inspection it was obvious that the outside of the tyre was taking a beating as it was obviously melting the rubber.

 

We know its not the best handling car in the world but it was cheap.. and we are not bothered if we stuff it.

we have put new standard shocks on the car and put 20mm lowering springs which are a little stiffer than stock..

 

what type of camber should we be running ? im inclined to go to about -1 on either side on the front... but i cannot find any values for castor etc for the rest of the geo setup.

 

Could we have some advice please

 

Adam

[Tony]

Off the shelf all that's adjustable is front/ rear toe and front castor, have you added any more adjusters??

[adam_r]

Hey Tony.

 

No we have not really modified the suspension setup apart from the shocks and springs.

 

would you be able to supply me with a rough spec i could show a local garage and just point and say do it to these limits ?

 

ideally we need to try and reduce the heavy wear on the outside of the tyres as it got quite bad at cadwell.

[Tony]

Difficult with no camber adjusters but for a dry track i would set her

Rear

Toe 0

 

Front

Caster as high as the adjusters will allow but no more than +5 degrees and even

Toe -30

 

You need to up the tyre pressure all round then test for over/under steer, if she understeers lower the front pressure if she oversteers lower the rear.

[adam_r]

interestiong that we have no camber adjustment i though ALL cars had that ?

 

what exactly will raising the castor do to the handling ? no idea what it castor does.

[Tony]

You need to try the toe and pressure examples as the first line of attack.... Since the car has been lowered i assume the front camber has a negative position? Here is where the castor comes in?

 

The Drifty in this image has really deep front camber, the turn axis/ castor and other events during yaw allows the camber positions to migrate.... One negative and one positive, look at the lean of the front wheels. In this high speed Drift the front tyres have maximum lock/ vertical camber and high front grip.... That's Drift for you.

 

Manipulation of the castor will help you maintain a as yet undisclosed migration to aid the tyres saturation limits.

[adam_r]

i need to buy you a beer at some point

 

so much about car suspension / geo i still have yet to find out about!

 

 

i guess the toe at -30 is toe out ? and that will cause the car to be more skittish when trying to drive straight but will aid turn in as the inner wheel will seem to be turning harder that the outer ?

[Tony]

A bit more skittish at speed but -30' is not a huge amount. The inner wheel is not working harder on the corner since the cars weight is on transition loading the outer tyre.