a lad who i know at work his brother has a corsa with a cav v6 in it , he says it spins the wheels in fourth although that sounds fast your never going to get anywhere because of shit traction its sat on cav gsi alloys. i would go for 2.0 8v strip it out fit front bucket seats and a roll cage maybe 14 or 15 " alloys and just go out and blow some more expensive cars away.
you cant beat the feeling of beating a bigger car, i know ive been on the recieving end , i raced a nova in my 325i beemer and i couldnt pass it !