GP4 and Cheat Engine

Hello folks, a thought occurred to me today when I was browsing through some GP4 stuff and I came across this thread discussing how to change tyre types of other cars and how this could be achieved with Cheat Engine (which for those none the wiser is like a Gameshark for PC). It made me think what else we could do with it; could we change things like magic data on the fly? Performance values perhaps?

I haven't had too much luck with it myself but I'm by no means an expert with this stuff. I tried editing the number of laps with the race still running but to no avail; not sure if it's due to my inexperience or if I didn't get the right code or if there's some limitation - has anyone else had a go at it?