Sr20 breaks up in boost

[240nessx]

So I recently put a stock redtop sr20 in my car. While driving if I do a pull in 1-3rd it'll break up around 4k rpm then pull fine after. In 4th and 5th above 4k rpm it'll break up bad and feel like it hit a wall. Under wot the a/f goes to 10.0:1.

It has brand new NGK bkr7e gapped to .028, new o2 sensor, new coolant temp sensor, the fuel pressure is at 43.5psi with no vacuum and 40psi with vacuum. At idle the motor is at 22hg of vacuum, the tps was voltage tested and was within spec.

The a/f ratio at idle is 13.3:1, cruising is at 14.6-15.1:1, and under normal acceleration its at ~12.5:1.

What would cause it to break up so badly?

[datsr510]

check all vac. lines and wastegate could be overboost from it not opening just my 2¢

[romero8287]

I'm having a similar problem, but my only happens
Between 4 and 5 rpm ... It feel like I hit a wall once it passes 5, I'm good... What is the problem?

[shanelach]

What about the simple stuff like coils? Boost leak test too.