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rear and front tyre temps
aka Keith - 7/9/09 at 09:45 AM

Took the car our for a spin yesterday evening and noted when I got home that the fronts were cool to the touch whilst the rears are warm. (this was also the case last week when I did a similar run).

The front end was not gripping as much as expected (which could be due to tyre temps)...anyone any ideas to try and improve the front end grip. (MK indy BEC - just in case).

cheers
Craig

[Edited on 7/9/09 by aka Keith]


nick205 - 7/9/09 at 10:06 AM

I would expect he rears to be warmer then the fronts, certainly on a rear wheel drive car.

You could try sofetning the front end dampers to up the front end grip a little. Too much might induce more tendancy to oversteer though.


britishtrident - 7/9/09 at 10:43 AM

If you have understeer the rull of thumb is soften the front or harden the rear.

Adjusting the dampers has an effect on the handling but only under transient conditions --- ie as you first turn into the corner. And in any case Seven style cars need the dampers set so soft it leaves little room for adjustment.

To alter the handling balance to give the car less under steer once the car is settled into the corner you need to either fit stiffer rear springs or softer front springs.

Be aware that you might end up with too much oversteer, Oversteer feels good but is slower and it can put you into the ditch very easily.


britishtrident - 7/9/09 at 10:45 AM

And you should also check the toe-in particularly on the rear too much rear toe-in causes understeer ---- but you need some rear toe-in or the car will have tend to snap oversteer.


procomp - 7/9/09 at 12:15 PM

Hi

Are we talking tyre temps just by feel of the hand. Or measured with an instrument.
As said in general the rears will be hotter due to being RWD. The front end grip or lack off is down to the poor geometry and camber control on the front of the Indy's. Start by checking tyre temps across the front tyres and correct the camber to even the temps out across the tyre width. To gain best results you need to be checking temps with a probe that inserts into the tyre. Using an infrared type gauge is useless as its only picking up surface temps not core temps which show much more accurately whats going on.

It is also a case that going softer on the front improves grip is a general saying. In actual fact in some cases going firmer puts more load into the front tyres and can increase grip significantly. You will be wanting to have the dampers and springs setup all looked at and putting into a working area before going to far into geometry otherwise you could be chasing your tail.

Cheers Matt


aka Keith - 7/9/09 at 12:49 PM

Matt, thanks for the post. this is most definately by hand - not probe measurement.

I only asked because when I used to have the RX7, (which has a FR set up) - after blat, the fronts and rears would be hot to the touch. --where as in the MK there is a marked difference in temp between front and back.

cheers
Craig