[wheeler]

Hello, I have a stock 09 WRX and ever since new (about 6 months) has a couple things that may be related, that I noticed that don't seem normal to me

1) Below 3500 rpm the car does not pull that hard and then at 3500 rpm it is like a SOB. I understand that the turbo is not making any real boost a low engine speeds but is it normal to have it come on all at once at 3500 rpm? It is almost hard to drive with this sudden surge of power right at 3500 rpm....

2) Occansionly, during hard acceleration, the power drops out / or is reduced momentary (about 1 second). I dont know why this occours but feels like the boost dropped suddenly (just my guess). This happens well below redline (3000-5500 rpm). Anyone else have this happen? I did read of some similar problems on this site, but all seemed to be related to aftermarket parts or incorrect tuning.


Thanks for any help on this topic

 

[booosted09]

well the power surge at 3500 rpm is just when your turbo is fully spooled...its a bigger turbo than on previous WRX's so there is a lot more lag...As for the power dropping off in that rev range, i haven't had that happen...it drops off right before redline but thats normal.

 

[baller_v24]

sounds like turbo lag to me. Does it do that when you downshift or try to gun it while in the 3000-5500rpm? Does it do the same when you try to gun it when you try accelerating at about 2500 or less rpms?

 

[booosted09]

sounds like turbo lag to me. Does it do that when you downshift or try to gun it while in the 3000-5500rpm? Does it do the same when you try to gun it when you try accelerating at about 2500 or less rpms?

I get real quick response when i'm at 3000-5500 rpm...no lag at all....its just on the 09's when your below the "party zone"(3500-6500rpm)these things just lag like a bastard. i just dont know about the drop in power.

 

[wheeler]

Thanks for the responses; Well lag i guess explains the sudden increase in power at 3500 rpm, it does not explain the intermittent loss of power. This occurs after peak boost is reached (or near peak) and well before redline. Does the engine ecu have a way of controlling boost, maybe momentarily reducing it for emissions? or to reduce intake temperatures?

 

[03 CrazyTaxi]

Almost sounds like it's overboosting or surging. Does it feel like you hit a brick wall or is more of a pulsing feeling?

 

[turmic]

Or is he talking about the way the boost falls off before redline? That he feels a power loss before redline. I mean that's normal and you can't really change that.

 

[wheeler]

Its more of of a surge or a very quick shutter, power drops for less than a second and then returns again. It happens about every other hard acceleration during every hard aceleration but about. It is not the power tappering off near redline, this happens at lower engine speeds and feels like a valve (may be wastgate) cracks open and bleeds off most of my boost - just a guess.

 

[booosted09]

i would just take it to the dealership and have them check it out...you dont have any mods do you? if not, it cant hurt to have them take a look.

 

[03 CrazyTaxi]

Def. take it in to the dealer, sounds like the wastegate may be dying.

 

[danrcv]

I have a 2010 WRX with this same problem since new. I am taking it in on Monday to the dealership. I know exactly the feeling you are getting. Power comes on around 3-4000 rpm then hesitates very slightly around 5000 then comes back on around 5500-redline. I have used Shell and Mobil (91 octane of course)and the problem is a bit more noticeable with Mobil. Its weird, it feels like the throttle is fluctuating. I will report back when I get the car back from the dealership.

 

[turmic]

It could just be a crap section in the stock map. That the car craps out for a second....who knows. Lets us know what you find.

 

[booosted09]

+1 to Turmic.......I talked to a guy who has a 09 that is completely stock except he took it and had it tuned. It is the stock map. The way Subaru set it up sucks....After the tune he said it dosent do it at all. Its real smooth through the rev's

 

[danrcv]

So the dealership said they found nothing unusual but if it still does it when I get 6,000 miles on the car to bring it back in. I was also informed that Subaru does not have an ECU update flash yet.

boosted09, what did the guy use to tune his car? Cobb?

 

[JPGC]

My 09 WRX does the same thing. It has 1150 miles on it. I am very curious on what it is. My car has done it from the day I left the dealership. I will pull really hard from 3500 to 5000, then at 5000 feels like it misses for a second, then pulls again.

 

[RcrsWetDream]

Yeah you guys are describing boost.... That's all it is. Turbo hits full spool around 3500 and then torque dies out around 5-5500. The 09's have the bigger turbo so it has more lag than say the 08's so you don't feel the speed until later but it lasts longer into the powerband.

 

[danrcv]

Yeah you guys are describing boost.... That's all it is. Turbo hits full spool around 3500 and then torque dies out around 5-5500. The 09's have the bigger turbo so it has more lag than say the 08's so you don't feel the speed until later but it lasts longer into the powerband.

Thanks for the feedback RcrsWetDream but I'm not sure that it's "just boost" I have had plenty of experience with other turbo cars and none felt like this. There is definitely a small hesitation around 5,000 rpm then it kicks again a few hundred rpm after and pulls strong to redline (6,500).

 

[JPGC]

Yeah, It's much more than just torque drop off. It's night and day when it happens. Has anyone been to the dealership yet with this issue. Thanks!

 

[VisiX]

Yeah, It's much more than just torque drop off. It's night and day when it happens. Has anyone been to the dealership yet with this issue. Thanks!

This sentence makes no sense. If you got boost cut and torque dropped off the car would feel like "night and day". Do you understand what torque is and how it affects your acceleration? Torque is a measurement of the force that is causing your wheels to rotate. It sounds to me like what you are all describing is some sort of boost cut and a lack of power to the wheels (loss of torque).

I think you all have the same terrible stock tune. If you get a stage one tune you'll probably be good to go. If you go to the dealership and it turns out to be something else please let us know but I doubt it.

Subaru is not likely to release an update for your ECU, the stock tune is not very good on any MY wrx and they haven't fixed it in the past.

 

[09azwrx]

Wheeler do you still have the stock exhaust? Mine did the same with the stock exhaust. I have since put a SPT CBE on, it smoothed out the hard push at 3500. The finish at 5500 i had noticed too.