Firstly, if your going to do it once, do it properly, visit
http://www.mercurymotorsport.com.au/ and buy a Hybrid Bar n plate intercooler, $550 shipped, brand new, 3" thick and 600 x 300. This way you won't be doing this job twice when the RX7 intercooler starts to do nothing, after 300hp is achieved from your engine.
Next best thing, exhuast, 2.5" mandrell is quite good, make sure you get a really well built dump pipe and a hi flow muffler, doesn't have to be a name brand, just so long as it's got some numbers behind it to back it up by an independant source
I would look into the suspension next, keep the original height, you'll thank me later. Maybe go a lower profile tyre, with some coil overs. Get some new shocks, maybe damp adjustable and a front strut brace. Try to get all the rattles out of the car aswell if you can and if you have any. It'll be alot more enjoyable that way.
MPI, yes but you'll need a VR4 Galant ECU or an EVO 1,2,3 ECU. I'm not sure if you can use normal Galant one because of fuel control for boost conditions need to be considered. It may be better in the long run and definately cheaper than an aftermarket EMS as it is illegal to run a car on the road with one of them, well in S.A. ??
Always leave the interior to second to last, tidy it up to almost new condition but dont go overboard as you'll get more resale from hp atw then leather interior, that's like putting a swimming pool in your backyard when you live in a housing trust home, you'll never get your money back.
Leave the brakes to last, like the rest of us hahahhahahah, they are quite adequete if you service the rear drums regularly, and use Lucas pads on the front. So long as you don't push more than say 200hp, that'll be fine.
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