To make a slightly longer story short, I have been running a JB+ on my GP2 for the past month or so and began having an issue with the car putting out significantly more boost than would be expected for a given setting on the JB. I removed the unit entirely in an attempt to revert the car back to the stock boost curve, but it is STILL putting out over 20psi at high RPM even without influence from the JB+ (read the full thread HERE).

Tech support at BMS is suggesting that the car may be seeing a surge in inlet temperature under prolonged WOT / high RPM conditions that is causing the boost curve to go out of whack. I can understand how that may be an explanation if the JB+ were still in place and messing with the DME, but again, removing it did exactly nothing to solve the overboost issue.

I am curious at to why the factory tune would push boost levels high enough to cause detonation (I had to run 100+ octane at the track to keep it from pulling timing) - has anyone else experienced this? Does the inlet temp theory sound plausible? Any thoughts on how to deal with this issue? I'm assuming the dealership will take one look at my car and throw me out the door with a $140 diag fee and some lame excuse about it being related to mods...

For reference: 2013 GP2, Alta CAI, Akra DP, Forge FMIC, 2nd cat delete. JB+ formerly installed but now removed from car. Factory tune.

 

Reset the DME.

 

I would check the waste gate flapper door for proper movement. You can reach under and try moving the arm back and forth to feel if it's opening/closing properly. A bent arm on the hinge of the flapper will cause the door to rub on the exhaust port. If wedged closed, you will see more boost. I've seen this happen intermittently and not throw a code until it got worse. For piece of mind, you could also pull the downpipe off and check the door alignment there.

Good luck

 

Doesn't the GP2 hit 21psi stock? If you've reset the DME and verified nothing mechanical is stuck, what are your air temps?

 

I told you this on another thread. I'll say it again for clarity. The GP2 sees up to 21psi in factory standard fully stock mode. This is normal.

I have 2 GP2's, and monitor boost in them, and they both see 21psi. Now this is not all the time, only in certain conditions, under full throttle. On the track this is very frequently, on the street a little less frequently.

The ECU only makes enough boost to make its target load. On the street when everything is cool, this is often only 17-18psi. On the track when things are heatsoaked, the boost often hits 21psi.

EDIT : saw on the other thread your car is pulling timing. Mine do not do that, usually see timing slowly rise to around 6 or so at these boost levels

 

Here's the basics. The boost is delivered based on a demand for torque. You will always see higher boost numbers in the summer. You will also see higher boost numbers at higher altitudes. In both cases the air is thinner requiring higher boost levels to meet the requested torque demand.

Adding any plug-in module will cause issues. This can lead to your ECU dumping boost down to around 6 PSIg. If you insist on running the plug-in module install this to control the boost spikes. http://www.boostvalve.com/mini-1.6l-turbo-fix.html

Several companies sell boost taps for your intake manifold. Install the MBC between a boost source and the waste gate.

And yes the ECU is constantly adjusting timing as required to keep the MINI from knocking (predetonation).

 

That's what I don't get - it was pulling timing all over on 93 octane; I'd hate to see what would have happened with 91! Once I got it up to somewhere around 96 it was more stable, with it tapering to 6 as you describe on the front straight - and yet in other situations, it was reading 4 and sometimes even 0 (CAN hi-jacked speedo only reads to 0, could have been less) under WOT conditions.

I disconnected the battery for about 45 minutes to "reset" the ECU; not sure if that would have been enough (BMS was suggesting I might want to clear DME adaptations, which requires special software). I will check IAT's today.

 

Have you monitored AF ratio? If the stock GP2 tune runs lean until 5k RPM like the S does the ECU has to pull timing under high boost/temps.