I've checked everything from coolant air pockets, igniter, plugs, timing. When I'm driving around town normal it drives perfect. When I'm on it full throttle for longer than a minute it dies out like it has fuel cut. It pulls very hard though & has zero issues besides this one issue.

NVM, it's a confirmed speed cut issue. Guess I need to go stand alone.

What do you mean, speed cut issue? I have a BT 20v in my ae86 and it's on the standard ecu. No bogging, I've done track days (well one!) and it was fine. I wouldn't say you have to go standalone.

Have you checked for blown transistors in your ecu, the sta wire, dizzy relocation kits had some issues,?

Same, I have 0 issues with stock ECU. I had an issue with the MAP sensor which caused bogging. I also had an issue where I was running the wrong plugs and would pull and then cut at around 7500ish—I was running COPs at the time. I switched out the plugs and didn’t have an issue after that. I then switched back to the dizzy relocation kit and have zero issues as well.

On another note, if you have a dizzy relocation kit, check to see if there is slop. Mine had that problem but it wasn’t as severe as others.