Rice is so tasty :-p
-The only cheap performance is advancing the timing.
-Air intakes won't give you jack. look at the stock intake, it's as big as the TB the whole length. rabid chimp makes one for the MKII supra that's close but not quite. that's it.
-For exahust 2.25 mandrel bent exhaust or 2.5" crappy bends, pacesetter or rabid chimp headers are all there is in that dept.
-of course there's turbos and 2JZs but that isn't the cheap route
-BY FAR the single best mod you can possibly do to make the car more fun and fast is to swap a W58 5-speed (use a MKIII NA supra for parts...all the parts)
-suspension: search around, there are starting to be a few options but not much short of coilovers. MKIII supra rear struts and springs fit in back with minor modding (drill 2 holes or dremel the strut mounts) for a 1.5" drop and negligeable increase in springrate.
other than the 5-speed, headers, or a 7mgte(BHG, rodknock)/JZ goodness ($$$) everything is custom
'90 Cressida, 7M-GE, M5 (2JZGE-T coming)
'91 Toyota Pickup, 22R-E, M5
'90 Suzuki VX800
"You don't get to judge me for how I fix what you break"