So a bit of background: It's an NA with a C30-74 on a 80mm pulley.
It's got an intake, header, exhaust, tiny Mazdaspeed intercooler, ID 725cc injectors, Walbro 190 fuel pump, MTX-L, and a MSPNP2.
It was tuned in a previous life, but I bought the car with a blown motor and rebuilt it with a forged bottom end.
With a more conservative timing map loaded, it fired up to life and drove around without a hitch up here in Colorado. It pulled strong and felt great.
I recently just trailered it down to Laguna Seca and it was stumbling and surging at idle. I had to give it gas until it warmed up so it would idle (poorly and surging from 900-1.2k rpm).
The big issue was that it would hit what felt like the limiter at 5.8-6k rpm? I'd watch the AFR spike from 12.5 to 22 and it would stop accelerating. It didn't have an issue running all the way to 7k at partial throttle, but would slam into a limiter every time I was wide open at 5.8k or so.
Here's a link to a log of one of the sessions. I'm sure I slammed into the limiter (if that's what it is) by accident a few times.
Anyone have any ideas as to what is happening?
Gonna feel pretty dumb if I pop the fresh rebuild. I've stopped driving it for the time being.