Nov 26, 2008 #1 J JoshM Member May 16, 2008 171 0 16 ...How can i increase the horsepower? I want to get more horsepower out of my 1999 Pontiac Grand Prix GTP. How can i do this? can you say how much it would increase by too? thanks!
...How can i increase the horsepower? I want to get more horsepower out of my 1999 Pontiac Grand Prix GTP. How can i do this? can you say how much it would increase by too? thanks!