Welcome to the North American Subaru Impreza Owners Club Friday May 6, 2016
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
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.
* Registered users of the site do not see these ads. 
Thread Tools Display Modes
Old 12-05-2002, 03:40 PM   #1
Scooby Newbie
Member#: 26900
Join Date: Oct 2002
Chapter/Region: NESIC
1988 Fiero Countach
G5 Rally Car

Question 2.5RS mechanical differences

I am shopping for a GC8 style 2.5rs, and am interested in what changes were made over the course of its 1998 to 2001 run. I know about the cosmetic changes for '99 and the sedan addition a year later, but I'm more curious about the mechanical differences. e.g. '00, '01 have LSD, '99 had MAF problems, are there any other mehcanical differences one might want to factor in when selecting a 2.5RS to buy? (Especially ones to consider with planned eventual significant modifications for the vehicle even possible ej20t, ej22t) Thanks
* Registered users of the site do not see these ads.
LIDGUY is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 12-05-2002, 04:03 PM   #2
Scooby Specialist
Member#: 4721
Join Date: Mar 2001
Chapter/Region: South East
Location: Asheville
2002 2.5 RS
1997 Brighton


1998 they used a DOHC
On all the newers they switched to a SOHC
Burnout is offline   Reply With Quote
Old 12-05-2002, 09:03 PM   #3
Scooby Specialist
Member#: 2953
Join Date: Nov 2000
Chapter/Region: MWSOC
Location: Rochester, MI, USA
2000 Impreza 2.5RS
2005 Impreza WRX STi


The MY00 has a MAP sensor, and the O2 sensors seem to malfunction, but have been recalled, so that shouldn't be an issue. The MY00 and MY01 have a remapped ECU, and 10:1 compression, instead of 9.7:1 as on the MY99, and I think the MY98 had 9.5:1, but I am not sure, it could be 9.7:1.

RebelINS is offline   Reply With Quote
Old 12-05-2002, 09:03 PM   #4
Scooby Guru
Member#: 1847
Join Date: Jul 2000
Chapter/Region: Tri-State
Location: brokenmotorsports.com
Team Broken: V6 GF


I would steer clear of 98s, cause they have known head gasket issues with the phase 1 DOHC motor, also weak rear diffes and axles.

the interior scheme is different as well, and no white faced guages.

the 99 - 01 is are all SOHC
99 had a MAF, the Mafs have recall.

00-01 have LSD rear diffs, and use a MAP sensor, not MAF, the map set up is much more performance intake friendly.

98 Phase 1 DOHC, known for bad head gaskets, and weak rear diffs and axle, uses MAF. lower compresssion ratio (gold 5 spoke wheels, small fogs) sma
so 99 = MAF, and No LSD (silver 5 spoke wheels, big fogs)
00 - 01 MAP and LSD (6 spoke silver wheels, big fogs)
IIRC the 00-01 have a bit higher compression than the 99s, but im not positive.

a little more info than you asked for, but more is better right heeh?

I would look for a 99-01 personally, leaning towards an 00-01 just becaue of the MAP

does that help?
munkis is offline   Reply With Quote
Old 12-05-2002, 11:27 PM   #5
Scooby Guru
Member#: 6637
Join Date: May 2001
Chapter/Region: MAIC
Location: Manassas
2009 Acura MDX Sport


I have a MY98 RS-T.. blown headgaskets, axles and diff are perfectly fine.

Just want to clear something up, if you want a GC8, go to japan, if you want a GC8 style, then you have to get a sedan
rhdude is offline   Reply With Quote

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
Differences between the 2000 SOHC 2.5rs and the 2004 SOHC 2.5rs rst4me Normally Aspirated Powertrain 9 01-25-2007 08:19 AM
what is the difference between a 2.5rs and the ts with the 2.2 engine for the gc8 bebeGDB Subaru Conversions 8 01-26-2004 10:08 AM
2000 2.5RS vs. 2002 2.5RS Differ? Lightning Jack Newbies & FAQs 0 04-13-2003 11:14 PM
2.5RS "blue" different from WRX "blue"? balajc Member's Car Gallery 20 03-28-2002 11:40 PM
2.5RS exhaust different than 2.5 TS wagon? mr_disco Normally Aspirated Powertrain 1 07-27-2001 04:47 AM

All times are GMT -4. The time now is 06:43 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2016 Axivo Inc.
Copyright ©1999 - 2016, North American Subaru Impreza Owners Club, Inc.