Hello this is for a s13 sr20det. I want to make around 400 hp.
What would be a good set-up. What size injectors, which turbo, ecu, ect.. Also what kind of internals would I need to upgrade? Thanks also which downpipe would be a good one and are Gp-Sprots mufflers good?

 

if you are gona make 400hp 100% of the time then internals are in order.
top feed injectors are good
do it right so there is less room for errors
i'm no turbo guru so what size or trim is a mystery to me too
find a good S15 turbo to use. thats all i can suggest on that one
you'll need some sort of fuel controller and boost controller. so just go Apex'i FC and save money in the long run
it really depends on what type of budget you plan on goin with. there are tons of options available for the SR20.
and tons of ways to cut corners and not jeprodize reliablity

 

400 flwheel HP or to the wheels? The S15 turbo will get you 300HP to the wheels, but I don't think it will be able to handle 400HP to the wheels. You will have to go with a T3/T4, or something to that effect for that. GP Sports from my experience has very nice body kits, not to sure about their exhaust setups though. I'd go with a Blitz, HKS, or Greddy downpipe if I were you. I would go with at least 550cc injectors to be on the safe side. Look to replacing your valve springs, and adding a set of rocker arm stoppers to protect your valve train.