I suspect that the graph you are after may not give you what you want because a car when moving is a dynamic situation. The load on the tyre, the friction coefficient of the road, the slip angle of the tyre, the castor and camber, the angle of roll of the car, the camber of the road, the forces applied to the wheel by the springs and damper are changing constantly. This why a car which is set up for a smooth track is hopeless when used on a bumpy one. For us mere mortals we usually spend a long time getting a good setup by trial and error. For top race teams they have complex chassis dynamics tables to jiggle them around or very very complex computer simulations. The best you can usually do is to reduce unsprung weight, buy the stickiest tyres, buy top quality springs and adjustable dampers, check out the camber and castor changes in the suspension and the movement of the roll centres with suspension movement. Make sure the anti roll bars are friction free, adjustable and effective. Then do lots of tests of cornering g and tyre temp across the tread to maximise everything. We had a spaceframe sprint car which was OK but when we spent a couple of days on setup of ride height, corner weights, castor, camber etc. etc. went from a 39sec run time to 36sec with same bars springs etc. We also found with a very light car on slicks that running with tyres flat to the track was no good as the rubber did not get hot enough to generate grip. By running with "excess" camber with the tyre and only using a portion of the available width the contact patch got hot enough to work and the car was much quicker - weird. This will not really apply to road tyres which are based on mechanical grip rather than chemical grip.
However you could always follow Colin Chapmans adage - if you want to go quicker add lightness.
Cheers
Mike
