Welcome to the North American Subaru Impreza Owners Club Tuesday March 19, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Archives > NASIOC Archives > Technical Forum Archive

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. 
 
 
Thread Tools Display Modes
Old 05-31-2000, 11:15 AM   #1
Momo
Scooby Newbie
 
Member#: 1544
Join Date: May 2000
Location: Norcal
Vehicle:
2012 SWP STI 5dr

Exclamation no acceleration in mid-5th??

Was trying to pass a concrete mixer truck the other day on I-5, and noticed that in 5th gear, between 3500-3800 rpm, there is literally no pull at all!! Is that normal? The engine is breathing through a Weapon-R intake, and it's screaming along at WOT. Is there a fix for the dead spot?

* Registered users of the site do not see these ads.
Momo is offline  
Sponsored Links
* Registered users of the site do not see these ads.
Old 05-31-2000, 01:15 PM   #2
boxerman
Scooby Newbie
 
Member#: 644
Join Date: Dec 1999
Location: Hoboken, NJ, USA
Post

Colin,
From the flat spot he describes, without any other infor I will guess that the combo of the MAP and the Weapon R is the culprit.

Even though the torque peak is supposed to be @ 4000, the torque multiplication in 4th vs 5th @3500RPM would probably put more torque to the wheels in 4th. I'm to lazy to look up ratios and do the math. If someone proves me wrong so be it.

From my experience and several posts by others it seems as if intake mods can cause very unusual responses from the MAP depending on whether or not the ECU is reset, the reset technique, the weather, your cars favorite color etc, etc, etc

I would first put it back to stock and see if the flatspot goes away. My car has no problem passing in that range either, other than 165hp/166lb/ft
Tim
boxerman is offline  
Old 05-31-2000, 02:44 PM   #3
Momo
Scooby Newbie
 
Member#: 1544
Join Date: May 2000
Location: Norcal
Vehicle:
2012 SWP STI 5dr

Post

I have a MY00 RS. Funny thing is, the dead spot was noticed BEFORE I put the intake in, and also afterwards. From what I understand, the ECU did not need to be reset (since there was no MAF, only MAP, or, that's what the dealer mech told me). You'd figure with all that hideous plumbing gone, things would clear up a bit...
Momo is offline  
Old 05-31-2000, 03:11 PM   #4
Sean McElderry
Scooby Specialist
 
Member#: 526
Join Date: Nov 1999
Location: Beaverton, OR, USA
Vehicle:
1995 Supra Turbo
Red

Post


Momo-

I've got a MY00 RS with no similar hesitation. Mine pulls pretty well in 5th throughout the RPM range. I'm thinking that what you're describing is not normal...anyone else with a MY00 care to comment?

Sean
Sean McElderry is offline  
Old 05-31-2000, 03:46 PM   #5
Gambit
Scooby Specialist
 
Member#: 102
Join Date: Jul 1999
Location: The meeting place
Post

Even my 2.2l pulls ok ( I stress OK!) at that speed in 5th on a highway. But recently I filled 'er up with some cheap gas and even a tempo beats me off the line now! aarrghhh!!!
Gambit is offline  
Old 05-31-2000, 07:56 PM   #6
Momo
Scooby Newbie
 
Member#: 1544
Join Date: May 2000
Location: Norcal
Vehicle:
2012 SWP STI 5dr

Post

Sean,

I'm wondering if it's the gearing issue? Fourth seems to pull all the way to the redline (and then some). BTW, my MY00 RS has about 1700 miles on it. Is it okay to start playing with it?!
Momo is offline  
Old 05-31-2000, 08:00 PM   #7
Momo
Scooby Newbie
 
Member#: 1544
Join Date: May 2000
Location: Norcal
Vehicle:
2012 SWP STI 5dr

Post

Sean, (again),

I hear that I should invest in a fuel meter thingy? Exactly what is this thing, and what does it do? What about AFC computer? I am so confused!
Momo is offline  
Old 05-31-2000, 08:02 PM   #8
Momo
Scooby Newbie
 
Member#: 1544
Join Date: May 2000
Location: Norcal
Vehicle:
2012 SWP STI 5dr

Post

Sean, (again),

I hear that I should invest in a fuel meter thingy? Exactly what is this thing, and what does it do? What about AFC computer? I am so confused!
Momo is offline  
Old 05-31-2000, 11:22 PM   #9
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

Post

My 2000 2.5RS NEVER had a flat spot before or after my intake mod. It pulls better in 5th gear from 80 - 120mph than ever before now.

Larry
ImprezaRS dot com is offline  
Old 06-01-2000, 12:00 AM   #10
SteveS
Scooby Specialist
 
Member#: 6
Join Date: Jun 1999
Location: South Jersey
Vehicle:
2013 BMW M3 Coupe
Interlagos Blue

Post

One word:

<font size="+3" color="red">forced induction</font>

Ooops! That's 2 words. Either way it still applies...
SteveS is offline  
Old 06-01-2000, 12:50 AM   #11
SKiDaZZLe
Scooby Newbie
 
Member#: 19
Join Date: Jun 1999
Location: Dallas, TX
Post

Steve, your cruel!
Although I almost posted the same thing to a post last week about getting rid of a dead spot.

In all seriousness, it is true. Boost = no dead spot. I love part throttle'ing it on the highway, and absolutely flying.

BTW, i used to have a dead spot without the turbo.

Michael
SKiDaZZLe is offline  
Old 06-01-2000, 12:51 AM   #12
boxerman
Scooby Newbie
 
Member#: 644
Join Date: Dec 1999
Location: Hoboken, NJ, USA
Post

Momo,
What year RS? If it is a 2000, I would take the Weapon R off and go to the stock plumbing. In my opinion the stock MAP system is THE major impediment when modifying the intake system.
You are also asking the motor to do alot, to accelerate this brick of a body in 5th @ 70mph.

Don't be so lazy, downshift to fourth.
Tim
boxerman is offline  
Old 06-01-2000, 12:56 AM   #13
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Talking

Considering the torque peak of the engine (by definition, where it pulls the hardest) is at 4000rpm, I think there's a problem but I don't think downshifting is part of the answer.

As much as I like the "turbo!" answer, my stock (powertrain) '99 RS has no problem with 70-90 passing in 5th.
ColinL is offline  
Old 06-01-2000, 04:03 AM   #14
cvalle-sd
Scooby Specialist
 
Member#: 420
Join Date: Oct 1999
Chapter/Region: SCIC
Location: The LBC, CA, USA
Vehicle:
2001 Cr-V
Silver

Post

I have mine dialed-in w/ AFC/ITC mojo, and good gas - pretty good pull in 5th.
cvalle-sd is offline  
Old 06-01-2000, 06:32 AM   #15
boxerman
Scooby Newbie
 
Member#: 644
Join Date: Dec 1999
Location: Hoboken, NJ, USA
Post

Momo,
Try a reset,
With the engine cold, disconnect the battery for over an hour (overnight if you can).
Reconnect battery, keep keys handy to stop the alarm.
Make sure everything is off.
Put key in the ignition, turn to accesory position so that the fuel pump will pressurize the sytem (3secs).
Without touching the gas start the car and let it idle.
Don't touch anything but watch the temp guage. When the car reaches operating temp and the fan cycles on, shut the car off without touching anything but the key.
Restart car and drive it like you stole it.

Be sure of the quality of the gas you are using when doing this proceedure. A bottle of octane boost may help if you are in doubt about what is in the tank.

I have a 2000, I experienced a similar flatspot after intake mods, and once after an improper reset (the AC was on, oops!). The car runs strong now everywhere after a proper reset.

If there is still a probem, visit your dealer.

Tim
boxerman is offline  
 

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
Black smoke, no acceleration, no good :( WRXstyle Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 13 08-18-2009 07:51 PM
No acceleration after certain rpms... UCDgogie Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 7 06-29-2008 03:14 AM
Nissan Altima Ranks No. 1 in Mid-Priced Sedans, Consumer Reports Says AVANTI R5 Non-Subaru News & Rumors 6 01-09-2008 07:47 PM
Harmonic noise while accelerating in 5th gear between 0 and 5 PSI? Cjchaps Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 2 05-12-2005 02:31 PM
Changed knock sensor now no acceleration! SubaruLover Normally Aspirated Powertrain 10 08-21-2004 11:59 AM

All times are GMT -4. The time now is 02:04 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.