V1.2 Nov 22 2006
This is a work in progress, and it has been a very long time coming. I intend on working on it for the next little while, dumping as much of my brain and hard-earned knowledge into the public record. It is, however, NOT public domain; I reserve the copyright for myself. You may NOT duplicate this elsewhere without my express permission - and this is the age of Google, folks, I WILL find you if you post it elsewhere. Otherwise, read and enjoy, and put this all to good use. Go fast!. DG
Consider the following: you invent a robot that can drive any car on any course on any surface and on any conditions, absolutely perfectly. As such, you can put this robot in any car, send it out on course, and the resulting time will be the quickest possible for that car/course/conditions.
Do this for three cars, and you might get a graph like this (taller is better):
Graph Forthcoming
From this graph, we see that Car A is faster than Car B which is faster than car C - when driven by our perfect robot.
But cars aren't driven by robots, they are driven by people. People are never perfect - occasionally they may approach perfection - but there is always some variability in their performances. We can represent this as a percentage value, where a given driver on a given performance achieves a given percentage of the maximum possible performance of that car.
Remember: NO driver can do better than perfection; no matter how good of a driver you might be, your best possible outcome is to equal the performance of the robot.
Now no driver ever drives exactly the same way every single run, and some drivers are better at approaching perfection than others. We can express the quality of a driver as two numbers: a minimum performance number, and a maximum performance number.
(Strictly speaking, we need a third parameter, a function that expresses the probability of a given performance level in that range. But I'm trying to keep this simple for the moment)
Consider Driver A. Driver A is very consistant, but he is consistant at underdriving the car. His minimum performance is 70%, and his maximum performance is 80%
Driver B is much less consistant, but sometimes he does very well. His minimum is 70%, and his maximum is 90%.
Driver C is a loose cannon, "spin or win". His minimum is 45% and his maximum is 95%.
If we put all three drivers in the exact same car on the exact same tires, we get a graph that looks like this:
Based on this graph, we see that any one of our three drivers can win; the determining variable being where in his performance range each driver winds up during the event.
Now let's say that Driver A goes out and spends a ton of money and winds up with a car that is 10% faster. Now we have a graph that looks like this:
In practical terms, that hasn't accomplished all that much, has it?
So how much faster does Driver A have to make his car so that he can expect to always beat Drivers B and C?
Would you believe fourty percent faster?
So you can see that the driver's influence on ultimate performance is by far the single greatest determinant of actual time, and that it can take a pretty big increase in potential car performance in order to offset driver performance.
Now admittedly, these are are artificial numbers, and they are probably exaggerated. There is a research paper waiting to be written analyzing the delta times between different cars in the same class, and particularly different drivers in the same car, at high-level events like Tours and Pros, to get a feel for the actual scale of variability driver to driver and car to car. My gut is that the range from slowest to fastest is on the order of 90%-98%. But the underlying concept is valid - it takes a whole lot of car to make up for an underperforming driver.
In practical terms, if you are getting beat, the first place to go looking for problems is in the driver; it is the driver who has the most effect on the car's performance.
Most red blooded males think that they spring from the womb the reincarnation of Ayerton Senna (not to mention Cassanova and Sgt. York) but that simply isn't true; driving in competition is a learned skill and not one that comes naturally to anybody. It must be practiced, practiced, practiced until it is mastered, and until it is mastered, there is very little that car tuning can do for you. There are no shortages of expensive, slow cars out there. No matter how much money and time you spend tweaking the car (and some have spent hundreds of thousands of dollars) money cannot overcome skill and physics.
Most of the times that I go beat, I got beat because I was outdriven, not outengineered. And most of the times I was outdriven, I put in a shitty performance where my opponent put in a good one. I beat myself much more often than I got beat despite my best efforts.
So then, why bother spending the money at all? If it's all driver, why waste any effort on the car?
Once the driving skill has been raised to a certain level, once you and your competitors are capable of putting in high-percentile performances, then the small differences between cars start to become signifigant. At the National level, performances amongst the top drivers are high enough such that the variation in potential between different tire constructions is of a similar order to differences between driver performances. Differences between other aspects of the car tend to be of a far smaller order than tires, but get enough small things right and they start to add up. Once you get good enough as a driver, you can get beat because you were on the wrong tires, or because your setup was suboptimal.
Of the number of times I got beat, I figure 75% of them were due to me not driving at my full potential, 20% of them due to being on the wrong tire, and the remaining 5% due to being on the wrong shocks/springs/bars. Of the people I beat (not counting blatent backmarkers) I think I only out-car-ed everybody (where there was no chance of me losing if I put in a decent performance) maybe once or twice - certainly no more than 5 times.
That ratio - 75% driver, 20% tire, 5% setup - feels about right, for cars similarily classed.
Bottom line here: learn to drive before you start spending money and turning wrenches; it's the best investment you can make.