If I want to go fast cheap I prefer to start with a factory turbo car. My DSM responded so well to everything I threw at it and never threw a CEL God bless OBD1.
Intake and exhaust netted me a half second quicker in the 1/4 and then a manual boost controller set about 5 psi above stock dropped another second (mid 13s) and then promptly needed a real clutch (ACT2600 did the trick) which is where it started getting a little expensive. A little hard piping,more fuel,air flow convertor (Apex S-AFC) and a couple sizes larger turbo and I was able to take down a last gen Viper with a little effort and never touched the engine. I was making about 400 at the crank for little more than $4000 and that was starting with a turbo car.
'12 Focus Red Candy SE Sport 5 spd
'99 Toyota 4Runner Sport
'11 Subaru WRX STI Hatch