Welcome to the North American Subaru Impreza Owners Club Thursday September 18, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Pre-2002 Factory Turbo 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.
Reply
 
Thread Tools Display Modes
Old 10-30-2012, 12:56 PM   #1
adamwilson301
Scooby Newbie
 
Member#: 327596
Join Date: Jul 2012
Chapter/Region: South East
Location: Charleston SC
Vehicle:
1999 Impreza 2.5 RS
World Rally Blue

Default 99 impreza 2.5 mod questions.

Just a few general questions if like to throw out there.
1. What kind of power can a 1999 2.5 RS handle (tranny, axels, motor mounts)?
2. Would it be safe to throw a turbo, intercooler, and blow off valve at 7-10PSI with no mods? Or should I get new pistons and get it closer to 8.1.1 compression?
3. With the Above listed mods in question 2 could I expect 250-270HP? That is about the range I am going for keeping it under 300.
4. What is the best size turbo and or pistons/crank and where is the best place price wise to order these parts?
I have more questions but with the phone app I'm not Ben sure I'm still typing a thread. Any advice is much appreciated. Thanks, Brian.
* Registered users of the site do not see these ads.
adamwilson301 is offline   Reply With Quote
Old 10-30-2012, 03:57 PM   #2
GGSimpreza
Scooby Newbie
 
Member#: 291739
Join Date: Aug 2011
Location: Harrisonburg, VA
Vehicle:
99 Impreza RS
Silver Milage

Default

Quote:
Originally Posted by adamwilson301 View Post
Just a few general questions if like to throw out there.
1. What kind of power can a 1999 2.5 RS handle (tranny, axels, motor mounts)?
2. Would it be safe to throw a turbo, intercooler, and blow off valve at 7-10PSI with no mods? Or should I get new pistons and get it closer to 8.1.1 compression?
3. With the Above listed mods in question 2 could I expect 250-270HP? That is about the range I am going for keeping it under 300.
4. What is the best size turbo and or pistons/crank and where is the best place price wise to order these parts?
I have more questions but with the phone app I'm not Ben sure I'm still typing a thread. Any advice is much appreciated. Thanks, Brian.
1. Search feature works great. Stock 5 speed is fine, but if you are hard on your tranny you will break things in your driveline. That goes for any AWD car. I have a 300chp swapped 99 RS, and my stock 5 speed has 191k on it and still works fine.

2. Do you mean a turbo kit for your stock bottom end? That gets expensive, and you won't be able to run enough boost to make it worth the money. Do a swap if you want boost. And BOV's are stupid, don't do it. Go under "newbies and FAQ" and read "Unibomber's Manifesto" for BOVs.

3. No idea, I've never done it, and every dyno puts out different numbers. Forget numbers and build a car that will be fun for you to drive.

4. Again, didn't do a turbo kit. Did a swap instead.

Also, do some searching with the search feature. A lot of people on here will get pissed at you for not doing your own reading.
GGSimpreza is offline   Reply With Quote
Old 10-30-2012, 04:09 PM   #3
adamwilson301
Scooby Newbie
 
Member#: 327596
Join Date: Jul 2012
Chapter/Region: South East
Location: Charleston SC
Vehicle:
1999 Impreza 2.5 RS
World Rally Blue

Default

Thanks a lot GG I appreciate it.
adamwilson301 is offline   Reply With Quote
Old 10-30-2012, 10:49 PM   #4
TommyAtomic
Scooby Newbie
 
Member#: 257043
Join Date: Sep 2010
Chapter/Region: VIC
Location: Vancouver BC
Vehicle:
1993 JDM WRX Wagon
Black

Default

Try the Bolton forced induction forum. Or at least try searching in that forum for the answers your looking for. The searching or asking here in the pre-2000 Turbo would be a good idea if you had a jdm import or a motorswap. Ask the wrong questions in the wrong forum and you will get some hate - for
good reason. Because your wasting peoples time.
TommyAtomic is offline   Reply With Quote
Old 10-31-2012, 12:48 AM   #5
adamwilson301
Scooby Newbie
 
Member#: 327596
Join Date: Jul 2012
Chapter/Region: South East
Location: Charleston SC
Vehicle:
1999 Impreza 2.5 RS
World Rally Blue

Default

Thanks. This would be easier if I'd just buy a computer. The app isn't really that great for research and asking questions.
adamwilson301 is offline   Reply With Quote
Old 11-06-2012, 10:18 AM   #6
GT45GC8
Scooby Newbie
 
Member#: 333957
Join Date: Oct 2012
Chapter/Region: South East
Location: hendersonville nc greenville s
Vehicle:
2001 impreza rs-swap
psm

Default

Not to burst your bubble i had a friend do this and unless you build the block kiss your engine goodbye. A stock rs with low mileage can take only so much like 7psi of boost ive seen multiple blow up on dynos. Ive even sold a turbo kit for an na where the piping and i dont know if your aware or not does not fit where the uppipe is supposed to go. You have to completely change that to a turbo crossmember or have custom fabricated piping neither is cheap. Id buy a wrx engine and tranny and harness for 3k and just swap it. Not trying to be rude but ive done all of this before i even have a thread in conversions where im swapping my 01 gc8 again with an built 04 sti complete with everything.
GT45GC8 is offline   Reply With Quote
Old 11-18-2012, 10:35 PM   #7
brownsa5
Scooby Newbie
 
Member#: 130994
Join Date: Nov 2006
Chapter/Region: MAIC
Vehicle:
2001 Impreza RSt
BRP

Default

Just some background: I have a turbocharged 01 RS, which I have put approximately 30k miles on. I bought the car with 15k miles, a 7psi turbo on a built motor, and blown stock tranny. I later dyno'd the car in that condition and it pulled 180hp. I put about 25k miles on the car in that condition (with proper gearbox). No axle or mount problems.

I upgraded the EM to a hydra, and Phil pulled 280 HP and 320 ft-lb at 17psi. The rear VLSD couldn't handle the torque, so I upgraded to a clutch type diff. Then I broke a rear axle. Fronts are still holding.

I recently blew the head gasket and possibly more. Not sure the cause.

As for your questions, based on my experience:
1) Trans<180HP, axles<280HP, mounts ok (but I would use group N)
2) Yes with mods. Use a reputible engine builder.
3) No, you need >15psi and you will break stuff.
4) Don't know. There were several kits available. Mine is a custom build with a T3

Good luck.

PS - I autox the car regularly along with street driving.

Last edited by brownsa5; 11-18-2012 at 10:36 PM. Reason: update
brownsa5 is offline   Reply With Quote
Old 11-19-2012, 11:02 AM   #8
V8Slayer
Scooby Specialist
 
Member#: 111565
Join Date: Apr 2006
Chapter/Region: W. Canada
Location: Winnipeg
Vehicle:
1999 Legacy 2.5GT
2007 Legacy GT Spec-B

Default

Quote:
Originally Posted by adamwilson301 View Post
Just a few general questions if like to throw out there.
1. What kind of power can a 1999 2.5 RS handle (tranny, axels, motor mounts)?
2. Would it be safe to throw a turbo, intercooler, and blow off valve at 7-10PSI with no mods? Or should I get new pistons and get it closer to 8.1.1 compression?
3. With the Above listed mods in question 2 could I expect 250-270HP? That is about the range I am going for keeping it under 300.
4. What is the best size turbo and or pistons/crank and where is the best place price wise to order these parts?
I have more questions but with the phone app I'm not Ben sure I'm still typing a thread. Any advice is much appreciated. Thanks, Brian.
1) As others have said, it all depends on your driving style.

2) It's definitely not safe to throw those parts on with no supporting mods. If your car is MAF, skip the BOV and recirculate the air back into your intake with a BPV. Your going to need additional fuel when running boost so upgrade your fuel pump and possibly injectors. Most na injectors can handle up to 5psi without issue, anything more then that and you will need larger injectors.

You will also need a way to reduce ignition timing since the na ecu runs a lot of advance timing(38* and higher in some spots). A lot of us AFI guys are running 5-6 psi and aren't having any issues, I'm running a TD05H 16G on meth and EWG, my stock motor is still going strong.

3)It's tough to say exactly how much power you'll be making, it all depends on supporting mods,tune, turbo, etc.

4)What do you plan on doing with your car, autoX, track days, DD? Once you deiced what setup you want to run, we can help you deiced which turbo will be right for you. Most people start out with a wrx TD04 since they are cheap and spool fast on a 2.5L, the downside is these turbo have a terrible top end.

Come check out http://forums.nasioc.com/forums/forumdisplay.php?f=50, lots of AFI builds and info to help you with this project.
V8Slayer is offline   Reply With Quote
Old 11-19-2012, 12:16 PM   #9
GT45GC8
Scooby Newbie
 
Member#: 333957
Join Date: Oct 2012
Chapter/Region: South East
Location: hendersonville nc greenville s
Vehicle:
2001 impreza rs-swap
psm

Default

This thread is dead
GT45GC8 is offline   Reply With Quote
Old 11-19-2012, 03:32 PM   #10
i_c_the_light
Scooby Guru
 
Member#: 88618
Join Date: Jun 2005
Chapter/Region: SCIC
Location: New Zealand
Vehicle:
1994 Legacy
"The Silver Slug"

Default

Quote:
Originally Posted by GT45GC8
This thread is dead
Ummm no. This isn't exactly a high traffic forum.
i_c_the_light is offline   Reply With Quote
Old 11-26-2012, 03:26 PM   #11
adamwilson301
Scooby Newbie
 
Member#: 327596
Join Date: Jul 2012
Chapter/Region: South East
Location: Charleston SC
Vehicle:
1999 Impreza 2.5 RS
World Rally Blue

Default

Thank you everyone. I just figured no one was answering my questions because I posted in wrong forum. Now I know I don't have notifications set up on my phone. I really appreciate all of your advice. After reading and talking to a few members I'm leaning towards WRX swap and EvoIII 16G with some other supporting MODs. Then I haven't decided on building the old RS 2.5 or selling it.
I'm sorry if anyone thinks I asked for advice and then ignored it when given as I said I had no idea I was getting replies!
adamwilson301 is offline   Reply With Quote
Old 11-26-2012, 08:31 PM   #12
DHRDAN
Scooby Specialist
 
Member#: 204358
Join Date: Feb 2009
Chapter/Region: SCIC
Location: Santa Paula, CA.
Vehicle:
01 2.5RS W/ EJ257
Black

Default

1. It does depend on your driving style.. but 300HP/tq is about it's max.... you'll probably blow the gears with time. Especially if you dump the clutch a lot.

2. Don't bother turboing the 2.5rs engine. Not worth it.


3. The 2.5rs engines i've seen turbo'd dont' go past 200hp. This is why even a WRX swap is better than spending money to turbo the NA.

4. Sell your car and buy a bugeye wrx instead. A great beginning car and it won't break the bank. If you're young.. you insurance will go through the roof.
DHRDAN is offline   Reply With Quote
Old 11-26-2012, 09:41 PM   #13
slayer44wagon
Scooby Specialist
 
Member#: 300834
Join Date: Nov 2011
Chapter/Region: MAIC
Vehicle:
03 wrx wagon
silver

Default

throw a LS1 in there and get that boostin
slayer44wagon is offline   Reply With Quote
Old 12-01-2012, 09:24 PM   #14
DHRDAN
Scooby Specialist
 
Member#: 204358
Join Date: Feb 2009
Chapter/Region: SCIC
Location: Santa Paula, CA.
Vehicle:
01 2.5RS W/ EJ257
Black

Default

bvahahahahahhahahahha
DHRDAN 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


All times are GMT -4. The time now is 07:29 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.