Everybody knows how much HP a redtop and a blacktop SR make. But a lot of people have been asking 'what will XXX YYY and ZZZ mods give me at the wheels?'
We'll start out with the basics that most people do when they do a swap. FMIC, downpipe, exhaust, and an intake of some form. The most power your going to get out of this settup is about 240rwhp. The stock MAF and injectors both run out of grunt at about that level. Anybody who claims to have over 250rwhp with the stock management system is selling you a load of BS. Everybody also knows that the S14 motor has a bigger turbo (T28) but people fail to realize that this motor will run out of steam at about the same HP level since it shares the same small 370cc injectors as the S13 motor. Now the bigger turbo will be more effecient and spool up a bit quicker, but the peak HP is still limited by the crappy fuel system.
If you don't have the big front mount your going to have to stay down on the boost a bit (no more than about 10psi or your asking for trouble). This is going to put you in or around the 200rwhp level. If you ditch the downpipe your going to loose another 10-15hp and exhaust is worth 5-10.
Also a side note, the stock fuel pump isn't going to support over 8psi (if your lucky) so please don't try it or your going to end up with melted pistons. Upgrade to the Z32TT, Skyline, or Walbro as one of your first mods.
Now let's take our SR with the 'basic' mods (240ish rwhp) and stick a T3/T4 turbo kit on it like the one
http://www.enjukuracing.com sells. With this settup your still going to be limited to the 240-250rwhp level due to the stock fuel system. But your going to be making those HP levels at a lower boost level (around 10psi) since the turbo is moving a lot bigger volume of air than the overworked T-2small. Let's throw on some bigger injectors and crank the boost up. 550's a Z32 MAF and some basic tunning will get us up to allmost 400rwhp but will be running on the edge of what they can handle. (it takes about 22psi to make 400rwhp with a basic 'big turbo' settup give or take a few PSI or HP). Now let's go play with the big boys and get up to the 460-480 rwhp range. Now your having to add cams, intake manifold, massive injectors and some really great tunning while still running in the 22psi ballpark. That motor will make over 400hp at as low a boost level as 15psi since it's opperating so much more effeciently.
This is all very basic info, and it's not even half as simple as I make it out to be, but if your a noob it should keep you from getting flamed if you read and understand this from the start. There are also some great articles on turbo's in general in SCC (the suck squeeze bang blow series gets in depth with them pretty well). Please just search before you ask, I'm sure you can find you own answers (which is more satisfying than having sombody feed them to you and safer since you can 'grade' the source as to their credibility)
anyhow, happy boosting
Paul