Gradual loss of power?
Thread Starter
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Joined: Mar 2003
Posts: 2,023
From: Phoenix, AZ
Car Info: Subaru Impreza WRX 2002
Gradual loss of power?
Hello all,
I've got a 2003 WRX that is just passing the 10k mark. I'm not an aggressive or "fast" driver -- I bought the car because my wife loves her Legacy wagon so much, she insisted I get another Subaru -- but I do enjoy a little kick from my car. The first few months I had my WRX I did indulge (after the break-in) in a little leadfoot driving, but speeding tickets being $110+ and gas being $2.05 for premium has slowed me down.
However, my WRX seems to be slowing down too. A lot of cars which I would leave in the dust (just normal driving, never getting over 3.5k on the tach) now smoke me from the stoplight. Passing on the highway seems tougher, and I've had some emberassing incidents such as getting cut off and passed by a Honda Odyssey minivan. It seems my WRX has lost a lot of "kick." As my engine is under 10K miles and I haven't fried my clutch, the only culprit would be the EMC controlling the air/fuel mixture, right? Or are there other factors in the engine that might gradually turn down the power over time?
I've got a 2003 WRX that is just passing the 10k mark. I'm not an aggressive or "fast" driver -- I bought the car because my wife loves her Legacy wagon so much, she insisted I get another Subaru -- but I do enjoy a little kick from my car. The first few months I had my WRX I did indulge (after the break-in) in a little leadfoot driving, but speeding tickets being $110+ and gas being $2.05 for premium has slowed me down.
However, my WRX seems to be slowing down too. A lot of cars which I would leave in the dust (just normal driving, never getting over 3.5k on the tach) now smoke me from the stoplight. Passing on the highway seems tougher, and I've had some emberassing incidents such as getting cut off and passed by a Honda Odyssey minivan. It seems my WRX has lost a lot of "kick." As my engine is under 10K miles and I haven't fried my clutch, the only culprit would be the EMC controlling the air/fuel mixture, right? Or are there other factors in the engine that might gradually turn down the power over time?
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How about just the fact that you live in Phoenix and it is probably frickin 110 there right now.... I don't know if anyone else has noticed, but the air conditioner practically deabilitates this car at low RPM. My car has 13,000 miles on it and on cool nights or early in the morning it still hauls ***. But on Hot days (it was 98 today) forget about it. Keep the windows up, the air on, the RPM's high and forget about racing anyone. It will still make power from 5 to 7 grand but you will get run over if you try to change lanes with the tac below 4000. By the way, I just installed a Greddy Evo catback exhaust and holy crap does it make a difference. The 11 or 12 HP you get doesn't say half of it, the car just breathes a ton better and you can really feel it on the top end.
Thread Starter
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From: Phoenix, AZ
Car Info: Subaru Impreza WRX 2002
You are right, I am driving with the AC on 100% of the time now, vs about 80% of the time when I bought the car, but turning off the AC doesn't make a dramatic difference in power; just a huge difference in the cabin temp!
I just hate the idea that I have to bury the needle past 4.5k RPMs to overtake cars that have less than HALF of my "theoretical" horsepower. Spooling up that turbo really cuts into fuel efficiency, in my experience -- still $1.90 a gallon for the good stuff?
Which brings up a thought -- here in AZ the pumps switch over to different gas in the summer, to cut down on ozone emissions. Could that have fooled the ECC into shutting down the air/fuel mixture? Should I just reset my computer and see if that helps?
Michael
I just hate the idea that I have to bury the needle past 4.5k RPMs to overtake cars that have less than HALF of my "theoretical" horsepower. Spooling up that turbo really cuts into fuel efficiency, in my experience -- still $1.90 a gallon for the good stuff?
Which brings up a thought -- here in AZ the pumps switch over to different gas in the summer, to cut down on ozone emissions. Could that have fooled the ECC into shutting down the air/fuel mixture? Should I just reset my computer and see if that helps?
Michael
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Man, you can reset the ECU all you want, but if you want to make power in this car you need to keep it in the 4K - 7K range. Take a look at the torque curve sometime. Probably shouldn't have bought this car if you were worried about gas mileage. It's not made to poke around short shifting, if you want power you have to wind it up....and that's half the fun!
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Joined: Jan 2003
Posts: 186
From: Union County, NJ
Car Info: Silver 2002 WRX
You do know that the WRX has forced induction, right? Trubos ALWAYS work better when their cooler. When you see people put ice on their turbo before races thats why. Where you live it gets so hot that you're going to lose quite a bit of power.
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From: Phoenix, AZ
Car Info: Subaru Impreza WRX 2002
Oh, I'm quite aware of all that, chumpsteak, what I am talking about here is an overall decrease in power from what I am used to, not a failure of the car to have power in the first place. Trust me, I'm not shy with the RPM when I need it, but when I do bury that needle it just doesn't have the kick it once did.
WickedWRX, would a difference of about 30 degrees ambient temp really hurt the turbo that badly? Is there room to upgrade the intercooler, or is there another way to aid cooling of the turbo? Most people here seem to rate exhaust and boost upgrades FAR more important than cooling upgrades -- do they all live in Alaska?
Chumpsteak, how much did that Greddy change the loudness of the engine?
WickedWRX, would a difference of about 30 degrees ambient temp really hurt the turbo that badly? Is there room to upgrade the intercooler, or is there another way to aid cooling of the turbo? Most people here seem to rate exhaust and boost upgrades FAR more important than cooling upgrades -- do they all live in Alaska?
Chumpsteak, how much did that Greddy change the loudness of the engine?
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Greddy Evo catback is the quietest exhaust next to stock. I think it was Turbo magazine that rated like 15 exhausts and the Greddy made as much power and was super quiet. Something like 93db at 3500 RPM where stock is 87db and most others are at least 100db. It's not loud at all, just gives that nice deep boxer rumble. You just have to live with an exhaust tip you can put your foot in.
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To be honest here I believe that the temperature of the turbo makes little difference. Exhaust gases are obviously extremely hot but they also have a lot of energy because of this. If the exhaust gases are cooled through the up-pipe and the turbo then the gases will lose energy and not move as fast. This could accually result in greater turbo lag.
The idea is that the exhaust gases should stay hot but the intake air temp be cold. I would suggest getting a new, larger intercooler. Either front or top mount. Just remember that the top mount is located right next to the turbo (only a heat shield separates the two). This is not good for heat soak.
The idea is that the exhaust gases should stay hot but the intake air temp be cold. I would suggest getting a new, larger intercooler. Either front or top mount. Just remember that the top mount is located right next to the turbo (only a heat shield separates the two). This is not good for heat soak.
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Joined: Mar 2003
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From: Phoenix, AZ
Car Info: Subaru Impreza WRX 2002
Thanks a lot, all of you, for your input. I'm learning a great deal about my engine in these forums!
I assume a misfire would set the computer off; I may upgrade the intercooler and also install a turbo timer. I've read on a few threads that modifying the intake produced little or no results, considering there is so little room to work with, but perhaps a higher-flow intake filter and an exhaust mod are the way to go. Or perhaps I will only drive at night :-)
A friend of mine made the suggestion that I should switch down a grade of gas (to 89) for a single tank every few months; have any of you heard of this, as a way of "training" the ECM and keeping the mix a touch lean?
Michael
I assume a misfire would set the computer off; I may upgrade the intercooler and also install a turbo timer. I've read on a few threads that modifying the intake produced little or no results, considering there is so little room to work with, but perhaps a higher-flow intake filter and an exhaust mod are the way to go. Or perhaps I will only drive at night :-)
A friend of mine made the suggestion that I should switch down a grade of gas (to 89) for a single tank every few months; have any of you heard of this, as a way of "training" the ECM and keeping the mix a touch lean?
Michael
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From: Huntington Beach, CA
Car Info: 03 Sonic Yellow WRX Sedan
there's really no way around the bog you get off the line, aside of revving it up high every time you launch. (thats what i have to do when my AC is on) mods like an up-pipe and downpipe and exhaust definitely give you more power and less lag cuz it allows the turbo to function more efficiently, but when the AC is on you just need to rev it up to 3k rpms and go cuz the turbo doesnt spool up instantly.
i am past 10k miles and feel a performance loss, however, i have also been constantly driving my car HARD and getting it DIRTY every weekend. So, who knows what it could be.
i am past 10k miles and feel a performance loss, however, i have also been constantly driving my car HARD and getting it DIRTY every weekend. So, who knows what it could be.