Do nothing to it at all. No extra turbo. No Nitrous.
A Minolta Toyota 88C-V will murder this event in stock form.
Tyres to R3 front, R2 rears as a last resort and pit at exactly 1/2 race distance whether you feel you need it or not = Easy win.
That said. Search the way it's been suggested, this has been covered an awful lot before and read the linked thread that Open Addict supplied.
Anyway, it's been covered 100 times before so feel free to discuss it further in one of the existing threads.