The more I think of this in-game, though, the more I worry. PI is a very good predictor of laptimes, from what statistical testing I've done (Check the PI project in my garage if you want the dataset and my methods). Getting rid of it may actually get rid of a major option for equalizing different cars. All in all, it does its job pretty well, if its job is allowing tons of different cars to be on the same track together. It fails on a few cars, IMO, and those are the leaderboard cars, but there seems to be a system there.
Basically, think of PI in two dimensions, not one. The north-south dimension is PI, from about 150 to 998 (lowest score to highest score that matters). Now, think of a left-right continuum from maximum grip to maximum power. Every car has a minimum amount of grip (stock weight and skinny stock tires) and a minimum amount of power (stock engine, no upgrades). Ignore for the moment the effect of weight, or just think of it as part of the grip equation if you prefer. A lotus comes stock with massive grip, weighing only a ton and basically having DOT tires stock. Compared to other cars of its PI, it's going to be underpowered. It suffers because of this at, say, Sunset, but makes up for this when you go to Tsukuba. The same is true of the MKII and Mugen Integra. In full-grip build, they have less hp than other similar cars. The Mugen is about 225hp IIRC at full grip in B, and most of the sockmonkeys weigh in around 250. The opposite is true for, say, the Charger. In B class, it has 1097 hp, and is on pretty poor tires. Basically, it only turns in theory. If you show up with this at King Cobra, you're in for a very long day. At Sunset, however, it should be very competitive, as it will cover the oval section in the blink of an eye.
How does this play out in the choices of LB cars? Simple. Most tracks favor either grip or power pretty decisively. The ability to hit warp speed on long straights or go through corners with the option of just letting off the gas instead of braking will make certain cars dominant on certain tracks.
How does this effect the PI-less spec? Well, my guess is that if we come up with a group of cars that have the same hp, weight, tires, and drag coefficient (as best we can figure-I think Blooze had a thread on calculating this), they'll all be at the same PI, or at least within a few points of it. They'll also be at the same point on my left/right, grip/power scale, if I were to operationalize it somehow. In short, my suspicion is that a PI-less spec will actually lead to LESS variation in the cars, not more. Of course, I could easily be wrong on this.
Thoughts?
