It never left.
I'll explain. For a game with 400+ cars and so many different ways to customize them, there would have to be a massive database to cover every possible setup for each car. I think it's done by an algorithm. Either way, the system makes mistakes. They seem more common with engine swapped cars.
It seems to start at the upper left of the settings sheet when adding up PP. It also seems to be less refined for parts you're not as likely to use like the stock transmission or a sports muffler, etc. I find the PP system generates fewer glitches or the ! when I have the "best" parts installed, especially with racing tires, mufflers, and air filters.
Get a relatively unused car, mismatch a tire set, say CH on front and RH on back, and you may get a ! for PP. If you're lucky, you'll get a number that actually drops when you go from CH to SH and then RH rear tires. If not, try installing a widebody kit and experiment with rim width, stance, and diameter until the PP rating becomes unstable on the tuning sheet. In some cases you don't need to mismatch the tires at all, the PP will destabilize without it, allowing you a multi stop race.
It helps to have aero parts. all the computers, a restrictor, and ballast available. You'd think with the same front to rear weight balance and the same HP to weight ratio the PP would be close. Not always. I've seen switching those settings up cut the PP in half. My 1.24 2J tune relied on something simar to get under 600 PP: the better computers can cut power output or have better power curves, but they add a set amount of additional PP. Transmissions are similar. If a stock part gives you satisfactory performance, use it even if you can't adjust it. On the 2J, I used the stock computer to free up 10-15 PP and then opened the restrictor up a little more.
Once you get parts on that generate odd changes in PP (or a !), start messing with the computer and restrictor. Set both to 70, then go step by step with one of them from 70-100 to see where the PP dips unexpectedly. Now increase the one to 71, rinse and repeat. When finished, try it the other way. If you started turning up the computer the first time, this time turn up the restrictor first.
When you set your downforce, also go step by step to see where PP dips.
Try changing other parts like the turbo, muffler, and filter.
Eventually you'll at least find settings where PP is lowest for a given set of parts, and if you're lucky, at some point it'll plummet to something crazy like 273.
If you start getting !, keep trying, as you're close to any available glitch tune.
Now, all that said, I don't care what you do with this info offline or where you post it or any results you get. By all means, grind with it. I do ask that you not apply it to online races or any single player events that award prizes outside of the game.
