First things first: this message is supposed to be helpful to the game developers, not to be misinterpreted as deriding their efforts. For casual racers, this cheat might make their day, but it might get old pretty quickly.
Anyway, as I couldn't record my record laps as evidence, you could test this yourselves. This can be done on my ovals (available at ) and on the default speedways as well. A stock car might be a good choice for your vehicle, though it's up to you. I don't know if the input device matters; I only have my keyboard for racing. Simuv2.1 in use, and no hacking or code manipulation involved.
This is how it's done: accelerate as fast as possible and go through the gears and let your car move right along the outside wall, even rubbing against it. That doesn't cause any real damage or slow you down, and that's really essential to those lightning-fast laps. You should be driving by the wall well before turn 1, and there you just keep accelerating with the car rubbing slightly against the wall, and the car hardly loses any speed as it zips through the turns. On straightaways/stretches, try to stay very near the wall too, so the car enters the turn smoothly and won't hit the wall awkwardly and spin or go airborne.
If the above explanation is too confusing, just try it out on a number of ovals (low- and high-banked), and pretty soon you'll get the hang of it. And real-life track records get broken in no time flat (e.g. incredible 16-second laps at ri-speedway, ~20-second laps at arizona, or 46-second laps at im-speedway), and it's not like the track surface settings (at least on my ovals) have been artificially improved.
Of course, I don't know if this is old news and the developers are well aware of this cheat, but at least now it's been exposed. For the sake of realism, that elusive concept in games, maybe this should be tackled at some point.