- that is true at 14psi it SHOULD be fine. i know this is for a stage 2 tune but the same principles would apply maybe? just a good read about boost control either way this response is from bill at cobb tuning
The original poster experienced a classic case of boost creep. There's a lot of myths/misconceptions about this - some things to keep in mind:
1. GR WRX is more susceptible to this problem. It is a combination of a number of factors (and the severity of each) that determines whether you may or may not experience boost creep at stage 2 level: catless downpipe, aftermarket intake, cold temperatures, and high atmospheric pressure. Doesn't mean that you have to have all of these to experience boost creep. For example, you can experience it with a catted downpipe.
2. It can be variable when it happens. Outside temperature is a big one in this variability - some cars may be fine in spring/summer but experience the problem when temps get cold.
3. When it happens in these severe cases/conditions, a custom tune by itself will not fix it. Neither will a 3-port BCS. You can see in this thread that Ian had the OP do some runs with the fuel economy map. That disable boost control completely so that the car would run the lowest level of boost possible ("wastegate" boost). From the logs, you can see that even at 0% WGDC, he is overboosting quite a bit above 5000 RPM, meaning the ECU has no control over boost and a custom tune cannot fix this (short of manipulating the throttle tables so that at WOT at higher RPM the throttle plate closes quite a bit - but this is just a band-aid approach).
4. There are a variety of solutions if you experience notable overboost and have already tried the severe low wastegate (SLWG) map (in the case of our OTS maps). If you feel comfortable doing so, you can use Accesstuner Race to modify your stage 2 map to disable boost control. This is done by setting the entire Wastegate Duty Cycle (High) table % values to 0, saving map, and reflashing to car. You can use the fuel economy map, but on some cars the rev limiter is lower (in the 5xxx RPM range) so it may not work for a full pull. Once you have boost disabled, get a run under the coldest temps you will experience (if possible). This will confirm severe boost creep if you still overboost. If not, then that means there may be some tuneability there, but the severity could vary quite a bit with different temps - so a map created on one day (in these cases where a tune may help) may hit proper boost levels, but overboost significantly when it gets colder out or underboosting significantly when it gets warmer out. That is why this is really a mechanical issue.
5. Solutions you can try include: A. If you only overboost with extreme temps, you can keep engine speed below 5000 RPM or so during those times if you don't want to proceed with a mechanical solution B. You can put the stock intake back on (and appropriate map) C. You can increase exhaust back pressure (catted for catless DP, stock catback replaces aftermarket). D. Go with external wastegate + custom tune E. go with wastegate port + custom tune.