Closed loop EBC overboots with cold temp

[hungdy]

I have my boost control tuned and it has been working good down to maybe the 40's ambient temp (70's MAT). Once ambient temp dips in to the 30's, it goes straight to overboost. Since the current boost control use the bias table as start values and adjust, it seems like it is not capable of compensating for temperature, at least not until it's too late. I have tried doing some minor adjustment of the bias table, and different PID settings, solenoid frequency, but none seems to work. I don't really want to do a completed re-tune of the boost control for the colder temp. The fast spool is nice, but it's hard to know when it'll overboost once temperature cools.

Anybody has any luck with tuning the closed loop boost control that work across the temperatures range? Or perhaps a potential future fix? Or do you just watch the boost gauge and don't use full throttle when is gets cold? Car is Mazdaspeed Miata with MS3. I asked the same question over at miataturbo.com and they said I may have better luck here.

-Derek

[benckj]

Can you not simply turn off boost control when below a certain temp? Most OEM controllers require a number of factors to be true before an increase in boost pressure above spring pressure is allowed (ambient temp >0C, coolant temp >70C, no knock detected, etc). This is a protection setting and can be circumvented for performance gains. Maybe a simple switch which includes ambient thermistor would suffice.

jim

[hungdy]

I could. I could also wire a switch in the dash and switch boost map since I have 2. But it would be nice if the ECU can compensate for it automatically.

[muythaibxr]

Are you sure it isn't a mechanical issue?