Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 11-26-2001, 04:26 PM   #1
jeffsnyder
Scooby Specialist
 
Member#: 10039
Join Date: Sep 2001
Chapter/Region: Tri-State
Location: NEPA
Question intake problems with WOT from a stop

i just installed my ralli-spec intake and modified it to work on a my98 2.5rs and it work fine i can feel a lot more pull it seems.

but i have one problem... when i go from a stop and floor it the car wants to stall out and just sits there heisitating,

and ideas whats causing this maybe i need a S-AFC or maybe the touqe chip will help. i was also thinking maybe because i still have stock exhasut on that its to much back pressure maybe. (waiting for cat-back and header)

any body with ideas or whats happing please help me

~JEff

PS its also an automatic
jeffsnyder is offline   Reply With Quote
Old 11-26-2001, 04:30 PM   #2
bouse1
Scooby Newbie
 
Member#: 8106
Join Date: Jul 2001
Chapter/Region: SCIC
Location: Whittier, CA (SoCal)
Vehicle:
2001 Impreza RSTi
Aspen White

Default

Did you reset the ECU after you installed the intake? You should try that. I don't think your exhaust is the problem. If you did reset it, then maybe there's a problem with your MAF. Good luck.
bouse1 is offline   Reply With Quote
Old 11-26-2001, 04:43 PM   #3
doobie
Scooby Specialist
 
Member#: 6570
Join Date: May 2001
Chapter/Region: South East
Location: Dunedin, FL
Vehicle:
04 WRXSW
9.3 TRB0 CNV

Default

I agree, sounds like an ECU thing. I use the ganzflow w/stock exhaust (cheapest mod to start) and have no problems.

good luck
doobie is offline   Reply With Quote
Old 11-26-2001, 04:55 PM   #4
jeffsnyder
Scooby Specialist
 
Member#: 10039
Join Date: Sep 2001
Chapter/Region: Tri-State
Location: NEPA
Default

ohh sorry forgot to add that i did it twice this weekend....

when i installed to intake the first thing that i did for that i woundn't forget is that i disconnected the battery for the reset

and i also did it again because i had to disconnect my battery to put my headlights in also

~JEff
jeffsnyder is offline   Reply With Quote
Old 11-27-2001, 02:33 AM   #5
HndaTch627
Scooby Guru
 
Member#: 6551
Join Date: May 2001
Chapter/Region: MWSOC
Location: Carol Stream, IL
Vehicle:
'01 GC8 Dinged STM
'09 Concours 14 ABS Black

Default

Make sure all your clamps are tight.

jeremy
HndaTch627 is offline   Reply With Quote
Old 11-27-2001, 07:35 AM   #6
jeffsnyder
Scooby Specialist
 
Member#: 10039
Join Date: Sep 2001
Chapter/Region: Tri-State
Location: NEPA
Default

i check over everything and its still the same

i was talking to my buddy about it and he said that it sounds like its getting too much air at one time and can't compansate for it. and whats its doing is the nock sensor is retarding the timming to compansate for the lack of fuel and its just too much for it.

he said that i should get a s-afc to control the mixture

what do u guys think

~JEff
jeffsnyder is offline   Reply With Quote
Old 11-27-2001, 08:44 AM   #7
Revision
Scooby Guru
 
Member#: 242
Join Date: Sep 1999
Chapter/Region: MWSOC
Location: Carol Stream, IL USA
Vehicle:
MY05 PSM GGA !STOCK
MY99 RS-RIP / MY95 MX-5

Default

Need more data.
Get an A/F meter and tie it in there. That will give you an idea of what is happening and if you decide to tune it later will help out a lot.

Until then, keep using part-throttle so the ECU uses the O2 sensors to compensate as the WOT maps are not very good.
Revision is offline   Reply With Quote
Old 11-27-2001, 10:35 AM   #8
IggDawg
Celebrity Guest Star
 
Member#: 10648
Join Date: Sep 2001
Chapter/Region: NESIC
Location: Sort of Boston, MA
Vehicle:
2008 Acura TL
Wicked Black

Default

Does that intake use the stock airbox? if not, you might be dealing with a moment of very low pressure when you first go WOT. This is an issue with some aftermarket intakes. Ganz and the such don't feel it, but most that require you to remove the stock airbox do. Cobb is just magic, so this doesn't happen with it. I rode in an RS with a Cobb intake and it was amazing.

But yeah... lack of airbox might be your issue. If rallispec does use the stock airbox, its probably an ECU or MAF issue.

-IggDawg
IggDawg is offline   Reply With Quote
Old 11-27-2001, 12:13 PM   #9
RaceCarRiot
Scooby Specialist
 
Member#: 6542
Join Date: May 2001
Chapter/Region: South East
Vehicle:
1997 Ver IV
silver

Default

any under hood j-tube style intake causes a split second of throttle lag when you stomp the gas...'tis the nature of the beast.
RaceCarRiot is offline   Reply With Quote
Old 11-28-2001, 09:11 AM   #10
scoobiejosh
Scooby Specialist
 
Member#: 3139
Join Date: Dec 2000
Chapter/Region: RMIC
Location: SLC Utah
Vehicle:
2015 Outback

Default

I had a huge problem with my MY01 RS stumbling all over the place, unless I was under full throttle. It turned out to be the front O2 sensor. Since the ECU uses the O2 sensor for partial throttle, but goes to maps inside the ECU under full throttle, the O2 sensor malfunctioning throws the ECU off when the pedal isnt to the floor. If your car works well under Wide Open Throttle, but stumbles under partial throttle, that would be my guess.

Josh:monkey:
scoobiejosh is offline   Reply With Quote
Old 11-28-2001, 05:48 PM   #11
spshultz
Scooby Specialist
 
Member#: 1415
Join Date: May 2000
Chapter/Region: RMIC
Location: Anytown, USA
Vehicle:
2015 F150 3.5EB
2014 Jeep GC

Default

I have a '99 RS Auto with Stromung Cat-back. At one time I had the J-Tube type intake but had a big loss of low end. Punch it and it would stumble then start to pick up. The top end was pretty good. Sure it was great once it got going but that little stumble was good for 1 - 2 seconds added to my 0-60. If I had a 5spd I probably would have kept it. And I don't brake torque at every stop light so I took it off and put the stock intake back on. No more stumble but a lot less top end.

Waiting for Compass Motorsports intake now.
spshultz is offline   Reply With Quote
Old 11-28-2001, 06:02 PM   #12
jeffsnyder
Scooby Specialist
 
Member#: 10039
Join Date: Sep 2001
Chapter/Region: Tri-State
Location: NEPA
Default

well i think the problem is what Racecarriot brough up... it just nature of the beast.

as for slowing down my 0-60 times i'll find this out on firday night at ATCO raceway.

so i guess i wait a few more day to find out what it did.

~JEff
jeffsnyder is offline   Reply With Quote
Old 11-29-2001, 10:07 AM   #13
imposter
Scooby Newbie
 
Member#: 10642
Join Date: Sep 2001
Chapter/Region: MWSOC
Location: Omaha Nebraska
Vehicle:
95 Impreza EJ22T

Default

im noticing the same thing. i have a j-tube intake on my 95 2.2L right now and before it was on my mom's Legacy 2.5GT. on both cars its done it and i recall being told that when you remove the box before the manifold you are removing the small reserve that the engine needs for the brief second it takes to get enough air moving again when you stomp it like that. I noticed a loss of low end but the sound the intake makes under hard acceleration makes it worth it IMO.

Jim
imposter is offline   Reply With Quote
Old 11-29-2001, 12:11 PM   #14
RaceCarRiot
Scooby Specialist
 
Member#: 6542
Join Date: May 2001
Chapter/Region: South East
Vehicle:
1997 Ver IV
silver

Default

i'm gonna say it once again...

if you don't want to lose low end, DON'T REMOVE THE AIRBOX!

put the stock system back on, take out the silencer, and put in a K&N or amsoil flat panel...sure you only gain maybe 1/2 the top end hp you would from a real intake, but you retain your low speed torque, and still get that nice roar at WOT.

i'm guessing you could get a section of tubing with fewer bends in it to run from the airbox to the throttle body instead of the stock black plastic one, and that may free up an extra hp or two.

plus, all it's going to cost you is the price of a new filter, and maybe 2 hours of your time.

-adam-
RaceCarRiot is offline   Reply With Quote
Old 11-30-2001, 12:11 AM   #15
Revision
Scooby Guru
 
Member#: 242
Join Date: Sep 1999
Chapter/Region: MWSOC
Location: Carol Stream, IL USA
Vehicle:
MY05 PSM GGA !STOCK
MY99 RS-RIP / MY95 MX-5

Default

Actually, if you tune it right, the only low end you will lose will be stuff under 1500 rpm. Think of it as a mild for of "turbo lag" without the turbo.
Revision is offline   Reply With Quote
Old 11-30-2001, 12:45 AM   #16
joltdudeuc
Scooby Specialist
 
Member#: 6119
Join Date: Apr 2001
Chapter/Region: BAIC
Location: Union City, CA
Vehicle:
1999 GM6
RBP

Default

Dude! I have the EXACT same problem, and guess what, it's my MAF Sensor!

I'm getting i new one... and not under warranty anymore either

I failed to note if you had a 99 and older (MAF) or a 00 and newer (MAP) cause then it's something else... but if got a MAF, look into that Sensor!

man, stupid fragile sensors on the 99!

-Gagan
joltdudeuc is offline   Reply With Quote
Old 11-30-2001, 07:50 AM   #17
jeffsnyder
Scooby Specialist
 
Member#: 10039
Join Date: Sep 2001
Chapter/Region: Tri-State
Location: NEPA
Default

nahh i don't think its the sensor because when i put the stock air box back on it didn't do it....

and i have a 98

~JEff
jeffsnyder is offline   Reply With Quote
Old 11-30-2001, 05:06 PM   #18
SCRAPPYDO
Scooby Guru
 
Member#: 873
Join Date: Feb 2000
Chapter/Region: TXIC
Location: www.testdrivemylife.com
Vehicle:
2020 JEEP / RAM
Datsun 71 240Z & 68 2000

Default

A couple of guys hit the nail on the head. The loss of power is dude to the lack of a reservoir of high pressure air to fill the intake manifold. Picture it. You are an engine sitting comfortably at idle. Then the butterfly on the Throttle body swings open creating a large change in pressure. On the engine side of the TB you have a vacuum trying to pull every last bit of air to fill its intake runners up in order to fill those cylinders. Now on the intake side of the TB you have this smooth pipe leading to the fender. It stands to reason that the slower a fluid moves the higher the pressure. Take for instance a water hose with a nozzle on the end. Stand on the hose and squeeze the nozzle, your feet will compress the hose a little. Close the nozzle and presto the water picks you up. Why should you care about this? Because the faster moving air through an intake tube us at a much lower pressure than the stagnant air in the stock air box. This means that the increased pressure the air box provides can respond quicker to rapid TB changes to provide the intake with the air it needs, where the smooth intake tube will take some time to "catch up" when the first initial TB input is processed and the tubes limited reserve is use up.

My advice is put the stock air box back on and use a smoother tube to replace the black plastic plumbing to the stock air box. In other words, get a Ganz type intake. You cant make one better for less than Larry does. Its one of the best engineered intakes out there. Its probably THE best intake for street use as a daily driver because it uses sound engineering principals that build upon the correct design already installed by Subaru from the factory. Any loss of low end is unacceptable in a street driven car. A Ganz will not cause you to loose any low end at all, while giving you a nice pull on the top end. The peak HP will not be as much as say a COBB or a Rallispec, but the 2-3 HP you may get for a few hundred RPM you will get them, is insignificant. Drivability is what is important.

Hope this helps.

SCRAPPYDO
stephen
SCRAPPYDO is offline   Reply With Quote
Old 11-30-2001, 06:54 PM   #19
p-car
Scooby Newbie
 
Member#: 5534
Join Date: Apr 2001
Location: OC
Vehicle:
2000 Cliffdiver RS

Default

Hey Stephen - what could you possibly know about this, you're just an engineer after all

Oh...hope you can make it to the pub tonite with us.
p-car is offline   Reply With Quote
Old 12-02-2001, 03:00 AM   #20
ImprezaRS dot com
over boosted again
Moderator
 
Member#: 1458
Join Date: May 2000
Chapter/Region: RMIC
Location: Colorado Springs CO USA
Vehicle:
2017 WRX Limited
15 Forester XT, 21 Ascent

Default

Thanks guys, I do sell two levels of GanzFlow intakes for a 1997-1998 that retain the air plenum, as well as for the 1999.

1) Just a cone filter with MAF adapter and bracket which retains the stock air plenum and the stock intake tubing, with only one version needed for 1997-1999, seen at www.ImprezaRS.com/product2.htm#filtermaf

2) An upgraded version that replaces the stock tubing between the MAf and plenum with a straight piece, including a vacuum nipple for the idle control line on phase I motors and another vesion for phase II motors, seen at www.ImprezaRS.com/shoppingcart.htm .

Both work well, the second one more so than the first. Someday I'll find the $175-$250 to dyno a stock and modified car, but for now it seems to do very well butt dyno wise.

Larry
ImprezaRS dot com is offline   Reply With Quote
Old 12-02-2001, 08:06 AM   #21
SuBart
Scooby Specialist
 
Member#: 2956
Join Date: Nov 2000
Chapter/Region: Tri-State
Location: Jerzey
Vehicle:
06 Sti-white Stg 2
98RS-rally blue

Default

It's normal (i think), same thing happens to me. I suppose it's just to much air for the engine at low rpm's
SuBart is offline   Reply With Quote
Old 12-03-2001, 04:18 PM   #22
SCRAPPYDO
Scooby Guru
 
Member#: 873
Join Date: Feb 2000
Chapter/Region: TXIC
Location: www.testdrivemylife.com
Vehicle:
2020 JEEP / RAM
Datsun 71 240Z & 68 2000

Default

SUBART,

Its the exact opposite. Its not enough air at low RPM. The small intake pipe does not have the reservoir needed to feed large changes in low rpm adequately.

SCRAPPYDO
stephen
SCRAPPYDO is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Problems taking off from a stop... undrgroundskat3r Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 4 06-02-2009 09:31 PM
Problem with swap from 02 RS rotors to 02 WRX D.Sweet86 Brakes, Steering & Suspension 1 11-27-2007 11:54 AM
Problem with audio from oem deck 02WRX VIP02WRX Car Audio, Video & Security 3 04-28-2006 08:32 PM
problem with first gear at stop dubX1 Service & Maintenance 29 07-12-2004 10:50 PM
Problems with Solid Metal Pitch Stop? Austin Brakes, Steering & Suspension 6 06-02-2002 12:34 AM

All times are GMT -4. The time now is 08:50 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.