OP Have you check the compression and done a leak down test? MAP did have a lot of issues with that series of turbo, but I would think it should still make more power than that. Either way, check the engines health and go from there. That HP is low. That would be low on a stock turbo.

 

A dyno graph can give us ideas of where to look. Do you have your dyno charts?

 

I get it. No worries. Can you at least say what timing is at redline?

My timing is nearly identical to yours. On a stock turbo still. The higher up it spools, the more base timing you should be able to run. But still, I would have to go into negative timing (again at peak tq) to go with/or over 26 psi. I'll take timing over boost.

 

Here is a dyno sheet (if it actually attaches) from I believe the second time on the dyno, it was running stupid lean so we only did 2 pulls I have since put bigger injectors and no longer runs lean I dont have any of the other ones on my phone so I cant put them up at the moment. I'll have to look at my laptop when I get home to see what the timing is set at.

 

I did a compression test before I started modifying it right after I bought it to make sure it was good:

#1 160
#2 165
#3 162
#4 155

this was with an analog harbor freight compression tester engine warm and throttle open. I haven't checked since then

 

looking at my "High octane ignition map 1" on ECU flash my timing at 7k from load 260-280 is *8