RB26 tech question

Hello fellow members.

I have an E30M3 that I've buildt an RB26 engine in. And have been developing and fine tuning it for a couple of years now so it will perform like I want to.

This years dyno session was a bit fuzzy. We experienced massive unstable MAP signal, and that cause the ECU to compensate with ignition.

Tha MAP signal that was collected to the DynaPack was collected from the same place as the ECU. But the DynaPack signal was dead stable. So the engine gets 1.3 bar, but the ECU think that is gets a variable pressure, and adjusts ignition thereafter.

The MAP signal is collected from the rail on top of the ITB's. We also did T all the vaccum outlets together and have threaded a nipple where the evap valve was on the middle of the rail.

Only change I have done from last year to this year was change from Borg Warner 7074 to 7670.

Engine cracked a ringland, so it is out of the car at the moment. I also experience some variable in the battery voltage.

Thanks

Bjorn.

To me it doesnt look like the timing jumps enougj to really make a difference. Maybe there is a filter you can turn on on the ecus map signal?

Cracked ringlands is often due to knock. What did the knock signal show in your logs? No. Wait...

Is it possible to post up log files instead of the pictures? It's a little tricky to get an idea of the scale on the graphs.

The DynaPack MAP input most likely has a different signal filtering arrangement to your ECU, so you can't really compare the two datasets directly.

Are you still running the OEM individual throttles and vacuum/boost reservoir?