Mild power adder, say you want around 200 rwhp.
Turbo Manifold
Blow Off Valve
Small Intercooler (potentially get away with a side mount)
Turbo T25/T28/14B, etc. Smaller T2 setups. Usually will be internally wastegated.
Downpipe 2.5" is perfectly fine
Replacing the Exhaust is starting to be very necessary at this stage, so I would start to shop for that as well.
Fuel Control
SR 370cc Injectors
Apexi SAFC2
Greddy Emanage
Back off base timing at distributor or MSD BTM
Average: 300 rwhp to 350 rwhp, you have to start to expect a little more lag. This is about the perfect "street car" limit. No race gas, just good honest street car fun that is fully capable of bring home a 12 second timeslip on a good run.
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No Front Bumper Mafia crew#1 since 04'
The original 350Z Blue 240sx