If you didnt see my "low power or on target?" post, it basically got summed up to needing timing and boost to hit higher whp numbers on this little *** turbo I have: (compressor: .42 ar 37.8 inducer 59.7 exducer 40 trim turbine .86 ar 52.9 inducer 45.47 exducer 73 trim.) basically a little too small for my goals, but super responsive ( in the area where I dont exactly need it to be)

I've been looking around and have found a very good opportunity to pickup an s15 turbo, which im pretty sure is the same as the gt2560 if im not mistaken. If i'm not, this would make more power at lower boost levels, but also keep my spool pretty quick on my vvt engine given the bb internals? Just want to have a safe 230hp on pump gas rather than full e85, and not have to bother going to multiple stations for flex fuel and keeping the e85 properties. 14411-91F00 is the pn


Also the question- what exactly is bad for the engine? there is volume of air, absolute kpa, and flow, Which one is the "watch out?" Basically if you take a boosted car, fat t3 making 15 pounds, and the same car, but with a tiny t25 making 15 pounds, the absolute kpa is the same, but does one stress the engine more than the other? It would be the t3, given they're larger turbos, with more capacity and volume to move air, which they do? Is it the boost pressure in in the engine that may cause issues? Say a car is making 25 psi of absolute pressure and all else is well, but only making 200whp, is it fine from a reliability standpoint (given no other factors like how the inefficiency could create more heat) I'm just a little blurry on WHY they cant take what they cant take. Ring gaps closing and block stress? Im aware the torque kills, just not aware which part helps it do that.

This is so poorly worded I hope someone can make out what im trying to understand here.

 

Boost is just the resistance in the whole system. Imagine a big compressor with a tiny exhaust wheel/housing. That thing would make big boost, but not a lot of power for a lot of reasons. What comes in, must get out, that's why bigger exhaust housings typically make more power. It all depends really, but the "watch out for" is cylinder pressure and EGT.
If you are like me and only do quick pulls here and there with time in between to cools things off a bit, you won't have any problems even with 0.6 rear t25 housings even at higher power levels. If you are staying on it for long periods of time, EGT will get pretty high and can cause bad things to happen. Knock, melted valves, pistons, broken rings and ringlands especially with stock gaps, melted exhaust wheels... Actually, I don't trust my own setup for a single Autobahn speed run!
But back to your question, 200whp at 25 psi absolute pressure is alright. Could make more like 300whp at 25psi with a g30, but your engine isn't strong enough. EGT would likely not be that much higher, if AFR and timing is on point like it seems right now. There is so much going on with efficiency and at which point in the cycle, you should read a book about it, if you're really interested