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Old 04-11-2003, 11:43 PM   #1
yamahito
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Unhappy sudden gain in power at 4,000 RPM?

Maybe it's always done this, but seems to have just started. When I floor it below 4,000 it has good power (don't get me wrong) but at 4,000 it's a sudden kick, I mean really noticeable (almost like a turbo kicks in).

It does this in all gears I believe but especially in 2nd and 3rd. I have about 40K on it. It's a '99 2.5 RS (manual). No mods, other than the intake silencer removed.

Is this normal and I've never noticed, or has something happened and am I missing out on available power below 4,000 RPM...thanks for any input.
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Old 04-12-2003, 08:03 AM   #2
pistoffjstr
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correct me if im wrong .....but isnt that were the tourque or horse power peak at ..mine dose the same thing at around 4500RPM
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Old 04-12-2003, 12:57 PM   #3
kturner
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Sounds normal to me. My car hits a peak right in there too. Interesting that it just now seems to be kicking in for you.
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Old 04-12-2003, 11:58 PM   #4
That Guy
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I notice it just before 3500 and lasting until about 5500 when it can't breath anymore. I always attributed it to the "stock tuned" sweet spot. You know, the intake runners, headers, exhaust diameter all optimized for that 2000 RPM range. But I'm prolly wrong.
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Old 04-13-2003, 05:34 AM   #5
Dr. Morbid
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I've thrown a bunch of mods into the engine and redone the exhaust and have always noticed that nothing seems to happen until at least 2000rpm. Then its like a magic sweet spot. Some mods "hit in" at 2500, some at 3500, but nothing seems to happen before those magic spots.
When I hit 4000 I blink and its like a shot of nitrous to the system when everything seems to gel to fruition.
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Old 04-13-2003, 06:13 AM   #6
Kevin Thomas
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This sounds like that spot in the torque curve where practically every Subaru would lose hp/torque then regain it back. You can see the dip and rise on most dynos between 3500 - 5300 rpm.
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Old 04-13-2003, 10:11 PM   #7
PeterJ
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Yep, I have that too. I started noticing it after 10k miles. It does it as long as it is not hot outside.
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Old 04-13-2003, 11:40 PM   #8
watcher in the sky
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my powerband is rather flat.. which i like.. i think you all are suffering from the famed hesitation problem. There shouldnt be a sudden pull.. mine has never done that .. and I've been driving her for over 55k miles. There may be this "surge" feel, but it isnt at some sweet spot, it just pulls from the bottom up. I will say that when i put my ganzflow on, it revved slightly faster around 5600 to redline.. but thats not a kick like you all have. I really think it's just a hesitation problem.. do a search on it.
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Old 04-14-2003, 01:26 AM   #9
JC
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Quote:
Originally posted by watcher in the sky
my powerband is rather flat.. which i like.. i think you all are suffering from the famed hesitation problem. There shouldnt be a sudden pull.. mine has never done that .. and I've been driving her for over 55k miles. There may be this "surge" feel, but it isnt at some sweet spot, it just pulls from the bottom up. I will say that when i put my ganzflow on, it revved slightly faster around 5600 to redline.. but thats not a kick like you all have. I really think it's just a hesitation problem.. do a search on it.
That's what I was thinking too.

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Old 04-14-2003, 05:54 AM   #10
zoinkssooby
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i had assumed this was normal since i have an intake. (weapon r) i had heard that they are made for breathing at higher rpms and that at lower rpms the velocity of incoming air was not fast enough to keep the "kick".
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Old 04-14-2003, 10:28 AM   #11
watcher in the sky
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this "kick" shouldnt be there... it should be pulling like that from really low.. Im not sure how low though.. as i dont putt off the line .. i usually dump the clutch. But you all oughta look into doing the grounding mod.. OR see if you have a bad o2 sensor.. maybe.
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Old 04-14-2003, 02:17 PM   #12
Teh Legacy
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This happened to me when i had my MY97 legacy GT....Does the engine actually sound different when this happens? If so, this may be the first signs of either a blown head gasket or a cracked block. This is only from my experience, so I may be wrong.
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Old 04-17-2003, 08:55 PM   #13
yamahito
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Hmmm...it stopped! I don't understand, I can't get it to do it anymore. I guess that's good, just would like to know what caused it?
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Old 04-17-2003, 11:50 PM   #14
That Guy
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Dunno, all. Mine's been doing it from around 3000 since I've had it. Got no problems with low end torque, mileage, or anything. Just aways had it pull hard after 3000. I actually count on it now.
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Old 04-20-2003, 11:21 PM   #15
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ive noticed that the car does lose air after 5500. so if i was "racing". should i shift at 5500. i been shifting at 6000 all the time.

my 1, 2, 3 gears are pretty good all the way through. but 4th gear after 5500, the car really feels like it is "dying".

my mods are...
apex n1 cat-back exhaust
injen cai
rallispec fast road cams
unothodox racing pulleys
magnecore sparks/wires
....4th generation borla header installed next week...
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Old 04-20-2003, 11:44 PM   #16
watcher in the sky
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man, with those cams and exhaust .. . your car should NOT be "dying" after 4th.... i no comprende!!!

seriously.. my car has a lightened crank pulley, and a ganzflow.. thats it for right now... but, it pulls OK, all the way through 4th... 5th is another story though
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Old 04-21-2003, 03:45 AM   #17
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I dont know what you mean by pulling through 4th, my cars just not fast enough. I have a Ganz, K&N, PROECM, Stromung Catback, and a LW Crank Pulley on the car and Borlas on order. I'm getting cams, a clutch, and flywheel as soon as I can though.
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Old 04-21-2003, 05:11 PM   #18
pimpomtic
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I have noticed this as well, But my check engine light is on and off all the time...

I think it is a bad O2 sensor..... Because I beleave a year or two ago I got a letter from subura saying there was a recall on a o2 sensor on 99's threw 01's and my car is a 01... But I understand what you guys are talking about....
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