CHRIS CLARK Posted October 24, 2000 Share Posted October 24, 2000 Thought this might be of interest! ADJUSTMENTS TO INCREASE UNDERSTEER. TO INCREASE OVERSTEER front pressure lower higher rear pressure higher lower front section smaller larger rear section larger smaller fr. wheel camber more positive more negative rear w/camber more neg. more pos. fr. springs stiffer softer rear springs softer stiffer fr. anti-roll bar thicker(stiffer) thinner(softer) rear anti-r.bar thinner(softer) thicker(stiffer) Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted October 24, 2000 Author Share Posted October 24, 2000 Sorry guys but 'it' takes out the relevant gaps!! I'm sure you can figure the spacings for the headlines though!!!!!! Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted October 24, 2000 Leadership Team Share Posted October 24, 2000 Uuuhhh??? Link to comment Share on other sites More sharing options...
Peter Carmichael Posted October 25, 2000 Share Posted October 25, 2000 Sorry, but this is in many ways rubbish. Presume that a tyre has an optimum pressure. If you go up or down from it you will reduce grip. QED. Link to comment Share on other sites More sharing options...
Mike Bey Posted October 25, 2000 Share Posted October 25, 2000 But that is what achieving balance is all about - changing the balance of grip from front to rear & vice versa - which often means reducing grip at one end, particularly if you start off with optimum grip (via optimum pressure). Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted October 26, 2000 Author Share Posted October 26, 2000 Well Peter' argue with the guys from BF Goodrich 'cos it came straight off off one of their racing set up charts. But then, I'm sure you'll know best? Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted October 26, 2000 Author Share Posted October 26, 2000 Stu F. To restore the correct layout read the text by clicking on my edit icon(magnifying glass). Try again!!! Link to comment Share on other sites More sharing options...
Mike Bees Posted October 27, 2000 Share Posted October 27, 2000 Maybe the BFG chart is telling you how to adjust the balance of the car, not how to get the optimum grip from each tyre... In theory Peter is right in that there must be an optimum pressure for a tyre in a given situation, and any other pressure will result in less-than-optimum grip. Sometimes it's worth accepting less-than-optimum grip for the sake of better balance, although I think there are often better ways of achieving balance than by reducing the grip at one end to match the other. Mike Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted October 27, 2000 Author Share Posted October 27, 2000 Mike. I would agree with that point. What I was trying to show was that there are so many variables that alter the 'feel' of the car that one solution for one individual can be a long way removed from another persons perception. It can also be that one change in a completely different 'dept.' gives a similar result to someone elses changes in a totally different dept.! B%$dy complicated when trying to set up for the 'optimum'. How to reproduce the same conditions after a change etc. Well anyway, one mans understeer is another one's oversteer!!! Cheers! Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted October 27, 2000 Leadership Team Share Posted October 27, 2000 Cheers Chris - sorted. If grip was all that was relevent we'd all be driving around on 255 wide tyres with geometry perfectly adjusted to give optimum grip at all cornering/lean angles. In the real world this would be madness. The whole reason behing the 13" wheel setup on the 7 is that it balances grip with handling. If you set up for the maximum grip senario then you're in trouble with any change in road surface, camber, rise & fall etc. Take rally driving as the extreme where the setup and driving style is orientated towards handling rather than grip? The chart allows the handling perameters to be adjusted within the bounds of maximising useable grip - essential for different conditions. It would hardly be practical to relocate the engine, to rebalance the car for a different curcuit!!! Stu. Link to comment Share on other sites More sharing options...
Mike Bees Posted October 27, 2000 Share Posted October 27, 2000 "If you set up for the maximum grip senario then you're in trouble with any change in road surface, camber, rise & fall etc." I don't understand this. However you set it up there will be some changes of conditions which reduce the amount grip. Better to start from a higher point than a lower one. If you set it up substantially sub-optimally then in some circumstances the available grip will increase, but you won't know when/where/how long for - it'll be highly transient anyway. "Take rally driving as the extreme where the setup and driving style is orientated towards handling rather than grip?" A very different situation and a very different piece of machinery! Throwing a 7 around sideways is fun but it's not fast. And we don't often drive flat-out over rough/rocky/gravelly off-road stages. Mike Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted October 27, 2000 Leadership Team Share Posted October 27, 2000 Absolutely Mike, the rally comparison is purely an extreme example of differing requirements in differing situations. The 7 is so light that it's necessary to endeavour to have strong handling characteristics, obviously tailored to a high level of grip. I'm not suggesting setting up the car for a sub-optimal level of grip, but that a minimal reduction in grip can be a worthwhile trade-off for more handling in certain circumstances. Try driving on a set of HPC wheels - masses of grip, sod all handling. Stu. Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted October 27, 2000 Author Share Posted October 27, 2000 Well I'm on 15" 'Prisoners' and Yoko 520's. Would like to try the new 15" CR500's. Anyone know the cost? Link to comment Share on other sites More sharing options...
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