Turbo?
 

What's a good turbo to make around 350-400hp?

You need to be more specific. For starters, what car do you have? Is it an FC, FD sequential twins, FD single, 20b swap, etc?

Yeah you're right that would help. I have a 93 FD sequential twins, with a v mount intercooler, pfc, downpipe, stock cat, cat back exhaust

Well these days people are talking about BW EFR

This or the Garrett GTX. But whats your plan with the car? Tracking it, 1/4 Warrior or daily. Stay within factory spool times or more safe boost later?

^ his right, depends what are your goals , budget & needs

Well I wanna be able to daily it and go on the track.

What about a set of hybrid stock twins? Bolts right up.

BNR Supercars - Bryan Nickell's Rotary Supercars - Mazda RX7 3rd Generation (1992-2002)

If I go single what specs am I looking for?

Without being rude , a bit of research will help you found the turbo to your needs

Looks like by your questions you're not too sure of what you want

Let's begin by what do you have in your car?

Oops I missed your post earlier, sorry
Still...some digging in the build thread & single turbo section will definitely help you ;)

Haha yeah definitely should of just looked around the forum more!

Go with garrett turbos !!!!!!!!!!!!!

Go with BW :P