My car has intake, 2 1/2 piping 3 inch exhaust, racing tranny when hitting 70 mph on fwy downshift to 3rd only around 4 thousand rpm,Civic Si has headers and exhaust. I've never raced an SI before he wants to race for money but i don't know would. If i cant beat him would headers enable me too? or just straight out turbo? I don't know much about cars just the basics, so don't diss cause I admit.