I have an 03' WRX w/ a Monster P&P TD-04, Process West CAI (65mm MAF tube), Gimmick Inlet, catless up, catless 3" TBE, Walbro 255 and an XPT stage II map.

I was driving the car tonight in about 50 degree weather and I was hitting 18lbs in first and 19lbs in 2nd and 3rd (I didn't want to push it in 4th or 5th). My car usually runs about 13-14lbs in 1st and 16-17lbs in 2nd-5th in the usual 70-80 degree daytime temps.

I have been running this map with these mods. for about a year and have never had a problem. I did notice that for a while the boost was surging so I tightened the wastegate a half a turn and it seemed to fix it. After a week I stopepd hitting target boost so I loosened it a half a turn. Everytime I did this I re-set the ECU. Now my boost is going up to 19lbs but holding then tapering off to redline like it should.

My question is what could be causing this?

P.S.

I'm sorry for such a long post but I'm trying to give as much info as possible.

 

Could have something to do with it being so cold out .

 

That's what I was thinking but shouldn't the car be able to compensate for that? I mean when these things are stock they're designed to be driven in Anchorage in the winter and Miami in the summer and not skip a beat.

 

But thats on a stock car. If your tuned at 70 degrees and its 40 degrees, thats a huge drop in temperature. shits gonna change!

 

Bcs? Or even get a mbc

 

factory tune is very very conservative to be able to cope with huge temperature differences. Over time, the ECU will learn a little more to get it nicer.

On a modified tune, the tune is designed to work best in the conditions during the tune. It's no surprise you're overboosting when its cold. Either get a second tune to switch (can 03's do that?), or take it easier in the cold.

 

the map should have a temperature compensation table... however, if you are running close to peak boost anyways it cant do too much


honestly, unless you are hitting fuel cut you dont have to worry. the fuel cut should be low enough to prevent any serious overboosting

if you really want to "solve" the problem, find a way to restrict exhaust flow. I had a reducer tip built for my exhaust that I would put in between tunes or when I went to more northern tracks. If you have a true custom tune, the tuner can adjust things for you. Since snowman tuned specifically for my needs (i.e. car to run at 100% for an hour straight) he left about 15whp on the table so that I would never have any issues. Before I went up to Road Atlanta (ended up being 40 degrees) he set me at around 16lbs and changed the temp compensation tables more so that I wouldn't have any issues.

 

So from what I understand if I were to re-set the ECU when it's 90 degrees out and the car learns those conditions, if the temp. were to fall to 50 degrees the ECU has not 'learned' those conditions thus behave a little erratic?

The tune I'm running was an OTS tune from XPT so it's fairly conservative (if fact I'm running the 91 instead of 93 octane map).

My biggest concern was that I'm going to be running lean at that high of a boost. Will there still be a fuel cut running an aftermarket tune?

One other thing: When I first flashed this map on (before the car really could learn it yet) I logged my IDCs and they were at a peak of 103%. Since then I've changed the fuel pump out for a Walbro 255 (stock pump had 116k on it) so I don't want to be pushing my IDC that high. I know my car is running ridiculously rich right now since there's a big puff of black smoke when I let off but I don't want to be running into any issue.

Thanks for the help guys.

 

there is no learned on the boost map to my knowledge. It will only correct through the turbo dynamics table which mean that as you are low on boost it gives you more wastegate % and if you are too high it will run the wastegate % Lower. but there is no learning on the ram that will change the wastegate % values.

since you adjusted the wastegate arm that is probably part of the reason it is over boosting. previously when you said it was surging it may have been trying to reach boost targets and causing it to fluctuate.

if you are over shooting lower the wastegate values on the map by say about 5 at the area its over shooting.

im not sure what boost cut is on that map, but im guessing its close to 20psi if its not considered a race map. you can just look it up on the map.

 

Hey dude I'm WRX_Fan from Nasioc.....check your email.