sudden gain in power at 4,000 RPM?

yamahito · 04-11-2003, 11:43 PM

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.

* Registered users of the site do not see these ads.

pistoffjstr · 04-12-2003, 08:03 AM

correct me if im wrong .....but isnt that were the tourque or horse power peak at ..mine dose the same thing at around 4500RPM

kturner · 04-12-2003, 12:57 PM

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.

That Guy · 04-12-2003, 11:58 PM

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.

Dr. Morbid · 04-13-2003, 05:34 AM

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.

Kevin Thomas · 04-13-2003, 06:13 AM

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.

PeterJ · 04-13-2003, 10:11 PM

Yep, I have that too. I started noticing it after 10k miles. It does it as long as it is not hot outside.

watcher in the sky · 04-13-2003, 11:40 PM

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.

JC · 04-14-2003, 01:26 AM

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.

JC

zoinkssooby · 04-14-2003, 05:54 AM

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".

watcher in the sky · 04-14-2003, 10:28 AM

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.

Teh Legacy · 04-14-2003, 02:17 PM

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.

yamahito · 04-17-2003, 08:55 PM

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?

That Guy · 04-17-2003, 11:50 PM

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.

AzNStiImpreza · 04-20-2003, 11:21 PM

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...

watcher in the sky · 04-20-2003, 11:44 PM

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

joefocker20 · 04-21-2003, 03:45 AM

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.

pimpomtic · 04-21-2003, 05:11 PM

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....

04-11-2003, 11:43 PM	#1
yamahito Scooby Newbie Member#: 31908 Join Date: Jan 2003 Chapter/Region: South East Location: Greenville, SC Vehicle: 1999 Impreza RS Rally Blue	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. * Registered users of the site do not see these ads.

04-13-2003, 06:13 AM	#6
Kevin Thomas Street Racing Instructor Moderator Member#: 110 Join Date: Jul 1999 Location: 1997 OBS, 1996 SVX, 1988 RX Vehicle: 1989 1989 XT6	Hrrmmm 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.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Knocking Sound between 3,000 -4,000 rpm	Sword_of_the_Spirit	Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)	1	02-05-2009 09:55 PM
Extra Vibration At 4,000 rpm in 2008 Impreza	hotweiss	Transmission (AT/MT) & Driveline	4	04-04-2008 07:47 AM
Power stops at 5,000 RPM	ItalianGuy	Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)	24	01-09-2008 11:40 PM
Strange surge in power at 5K RPM	bleat	Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)	22	09-17-2005 12:17 AM
Dead spot at 4,000 RPM?	The Wraith	Normally Aspirated Powertrain	14	07-17-2001 10:38 PM

04-12-2003, 08:03 AM	#2
pistoffjstr Scooby Specialist Member#: 29283 Join Date: Nov 2002 Chapter/Region: Tri-State Location: Bangor PA Vehicle: 2003 Subaru Forester Red	correct me if im wrong .....but isnt that were the tourque or horse power peak at ..mine dose the same thing at around 4500RPM

04-12-2003, 12:57 PM	#3
kturner Scooby Newbie Member#: 8225 Join Date: Jul 2001 Location: Corvallis, OR	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.

04-12-2003, 11:58 PM	#4
That Guy Scooby Newbie Member#: 23212 Join Date: Aug 2002 Chapter/Region: MWSOC Location: Milwaukee, WI Vehicle: 2002 Impreza RS	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.

04-13-2003, 05:34 AM	#5
Dr. Morbid Scooby Newbie Member#: 24945 Join Date: Sep 2002 Chapter/Region: W. Canada Location: Medicine Hat, Alberta Vehicle: 1994 Burnt In Fire White Metal	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.

04-13-2003, 10:11 PM	#7
PeterJ Scooby Newbie Member#: 14727 Join Date: Jan 2002 Vehicle: 2002 impreza RS	Yep, I have that too. I started noticing it after 10k miles. It does it as long as it is not hot outside.

04-13-2003, 11:40 PM	#8
watcher in the sky Scooby Specialist Member#: 3513 Join Date: Jan 2001 Location: NC Vehicle: 1997 Legacy Outback White	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.

04-14-2003, 05:54 AM	#10
zoinkssooby Scooby Newbie Member#: 18910 Join Date: May 2002 Location: portland oreeegone Vehicle: 2000 mr2 spyder silver	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".

04-14-2003, 10:28 AM	#11
watcher in the sky Scooby Specialist Member#: 3513 Join Date: Jan 2001 Location: NC Vehicle: 1997 Legacy Outback White	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.

04-14-2003, 02:17 PM	#12
Teh Legacy Scooby Specialist Member#: 9853 Join Date: Sep 2001 Chapter/Region: International Location: Never miss an opportunity Vehicle: to keep your mouth shut.	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.

04-17-2003, 08:55 PM	#13
yamahito Scooby Newbie Member#: 31908 Join Date: Jan 2003 Chapter/Region: South East Location: Greenville, SC Vehicle: 1999 Impreza RS Rally Blue	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?

04-17-2003, 11:50 PM	#14
That Guy Scooby Newbie Member#: 23212 Join Date: Aug 2002 Chapter/Region: MWSOC Location: Milwaukee, WI Vehicle: 2002 Impreza RS	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.

04-20-2003, 11:21 PM	#15
AzNStiImpreza Scooby Specialist Member#: 17181 Join Date: Apr 2002 Chapter/Region: MAIC Location: Clarksburg, Maryland Vehicle: 2015 Subaru WRX Red / 2012 RR Evoque	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...

04-20-2003, 11:44 PM	#16
watcher in the sky Scooby Specialist Member#: 3513 Join Date: Jan 2001 Location: NC Vehicle: 1997 Legacy Outback White	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

04-21-2003, 03:45 AM	#17
joefocker20 Scooby Specialist Member#: 13745 Join Date: Dec 2001 Chapter/Region: MAIC Location: Delaware Vehicle: 2015 STI WRB	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.

04-21-2003, 05:11 PM	#18
pimpomtic Scooby Newbie Member#: 2699 Join Date: Oct 2000 Location: Sebastian ,fl, Home of the old people Vehicle: 2001 2.5 RS- ????? Silver	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....