Subaru Impreza RS 2.5 Turbo Build-Up
#1
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Subaru Impreza RS 2.5 Turbo Build-Up
Hi guys. So far I've been at this forum researching for the last 20mins...and I have learned so much. After all of this knowlage I learned and all of the information that you guy's provided, I just had to join and post some questions that have been brought up.
A. How much potential does the EJ25 motor/trany have with a turbo setup?
B. Can I swap out the EJ25 SOCH cylinderhead for a EJ20 DOHC cylinderhead?
C. What's the best compression ratio pistons to use? Who makes the best?
D. Who are some manufacturers for engine block internals?
E. Who are some manufacturers for cylinderhead internals?
F. Which is better, 1. Buying a Pre-Fabed kit. Or 2. DIY (doing it yourself) custom turbo kit?
G. Who makes the best 2.5" to 3" cat-back exhaust, that makes a low rumble and provides nice bass and let's people know that I'm coming? But, it can't be ricey or sound ricey.
H. Can I do all of this and still stay emissions legal?
Here are the other information need to answer me questions:
1. I want a nice performance street driver that can still pass emissions.
2. I want to be the quickest I can be. (what ever that maybe with still in emissions)
3. I have about $6,000 to spend on this project.
Please help. Thank you for your time.
A. How much potential does the EJ25 motor/trany have with a turbo setup?
B. Can I swap out the EJ25 SOCH cylinderhead for a EJ20 DOHC cylinderhead?
C. What's the best compression ratio pistons to use? Who makes the best?
D. Who are some manufacturers for engine block internals?
E. Who are some manufacturers for cylinderhead internals?
F. Which is better, 1. Buying a Pre-Fabed kit. Or 2. DIY (doing it yourself) custom turbo kit?
G. Who makes the best 2.5" to 3" cat-back exhaust, that makes a low rumble and provides nice bass and let's people know that I'm coming? But, it can't be ricey or sound ricey.
H. Can I do all of this and still stay emissions legal?
Here are the other information need to answer me questions:
1. I want a nice performance street driver that can still pass emissions.
2. I want to be the quickest I can be. (what ever that maybe with still in emissions)
3. I have about $6,000 to spend on this project.
Please help. Thank you for your time.
#2
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whew, that's a lot of questions in one shot.
A. Engine has unlimited horsepower potential with enough $$
Tranny maybe 350-375
B. 2.5 heads flow great, this swap is expensive and unnecessary.
C. I would go with 8.5-1 pistons, and JE makes a great set for the 2.5. Others make them as well.
D and E. Contact i-speed, vishnu, or Rallitek for internal info. Pistons and rings should be sufficient for as much power as your tranny can take.
F. Definitely buy a pre-fabed kit. I could go on and on about using Legacy and WRX parts in my '98, but you'll save time, money and sanity buying a pre-made kit. The list of parts needing to be retro fit by DIY is extensive.
G. Apex'i makes a good exhaust, check out WRXhookup.com for others.
H. Get emissions before you do the swap. Good luck passing without cats.
If I was in your situation, I would get the Forced Air twin ball-bearing turbo setup. There's lots to choose from. Good Luck.
A. Engine has unlimited horsepower potential with enough $$
Tranny maybe 350-375
B. 2.5 heads flow great, this swap is expensive and unnecessary.
C. I would go with 8.5-1 pistons, and JE makes a great set for the 2.5. Others make them as well.
D and E. Contact i-speed, vishnu, or Rallitek for internal info. Pistons and rings should be sufficient for as much power as your tranny can take.
F. Definitely buy a pre-fabed kit. I could go on and on about using Legacy and WRX parts in my '98, but you'll save time, money and sanity buying a pre-made kit. The list of parts needing to be retro fit by DIY is extensive.
G. Apex'i makes a good exhaust, check out WRXhookup.com for others.
H. Get emissions before you do the swap. Good luck passing without cats.
If I was in your situation, I would get the Forced Air twin ball-bearing turbo setup. There's lots to choose from. Good Luck.
#4
Originally posted by Impreza2.5RS
hey thank you
who makes close gear ratios for the rs 2.5?
any recs. on apexi or any other exhausts
hey thank you
who makes close gear ratios for the rs 2.5?
any recs. on apexi or any other exhausts
Tats.
#5
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Ok. Thanks for the Information. Will the EJ20 Tranny fit DIRECTLY on the EJ25 engine with NO modifications? I would hope so. Please reply.... oh...if anyone that's knows somewhat a lot about turboing a N/A Subaru Impreza RS 2.5 please IM me at DJDude98. I need to know where to start with the first modification. And maybe suggest some things too. Okay. Please reply. Bye.
#6
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That's the great thing about Subaru's. Their drivetrain setup is identical throughout the model lineup. You might need a few minor mods like new mounts or brackets, but the tranny will bolt right up. For something like $7,500 you can get a complete EJ20 and WRX tranny I believe with turbo, intercooler, and ECU INSTALLED! Check out i-speed USA. There's also a canadian company that can do it for a great price, but I can't remember their name. I'll get back to you. The first step is to research all your possible options. Don't get all excited and start buying random parts. Odds are you'll end up with some you don't need, or that your system won't function as well as you'd like.
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#7
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-Impreza7
thanks a lot for the information. here's kind of a stupid question:
How do I research things? what should I research? because I suck at research. like I'm researching for an exhaust right now...and I can't find for what I'm looking for. Can you gimme some help....or better yet...can you gimme some tips on how to research? thanks. bye.
thanks a lot for the information. here's kind of a stupid question:
How do I research things? what should I research? because I suck at research. like I'm researching for an exhaust right now...and I can't find for what I'm looking for. Can you gimme some help....or better yet...can you gimme some tips on how to research? thanks. bye.
#11
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Join Date: Nov 2002
Location: Reno, NV
Posts: 18,369
Car Info: 1993/2000/2001 GF4 mostly red
Lachute Subaru is the Canadian company you were thinking of, but I'd recommend i-Speed personally.
Also, if you get a new transmission, get a 6MT or at least an STi RS gearbox. USDM WRX trannies aren't all that strong either, not enough to be worth the cost and effort of a swap anyway.
Also, if you get a new transmission, get a 6MT or at least an STi RS gearbox. USDM WRX trannies aren't all that strong either, not enough to be worth the cost and effort of a swap anyway.
Last edited by Kevin M; 06-02-2003 at 07:10 PM.
#12
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Okay. Thanks for the information! I'm actually considering a Subaru Impreza WRX now. Instead of the 2.5 RS. Because, when I was "researching", I found out that aftermarket is a little short for the 2.5 RS, and that there's more for the WRX. I'm not sure, please correct me if I'm wrong. Thanks so much for all your help guys. You've been a big help. I'm come up with a parts list. I can remember some. I'll list them, and then I'll post the rest when I get home from school:
TurboXS Turboback w/ Catpipe (the catpipe will be swapped in and out)
TurboXS Racepipe (this will replace the cat when I don't have emissions)
WRX Tuner "GT-Spec" Header
Vishnu OEM Remapped ECU
TurboXS FMIC
A'PEXi SAFC
I have some more parts on the list at home. Hence, "I'll post the rest later."
Peace out.
P.S. The above parts listed are for the Subaru Impreza WRX turbo awd
TurboXS Turboback w/ Catpipe (the catpipe will be swapped in and out)
TurboXS Racepipe (this will replace the cat when I don't have emissions)
WRX Tuner "GT-Spec" Header
Vishnu OEM Remapped ECU
TurboXS FMIC
A'PEXi SAFC
I have some more parts on the list at home. Hence, "I'll post the rest later."
Peace out.
P.S. The above parts listed are for the Subaru Impreza WRX turbo awd
#13
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Location: Reno, NV
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A WRX is the better engine platform to start with, but the '98-'01 RS has more options for suspension. An RS with an EJ20 swap probably has the most potential of any Subaru.
#14
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I don't see why. When the EJ20 is still in the subaru wrx and if it has potential...then why swap it into the RS? same motor...different car....the actually form of the car don't mean anything (I think). iight here's the rest of the parts
TurboXS Turboback w/Catpipe
TurboXS Racingpipe
WRX Tuner GT-Spec Header
GReddy Airinx Intake
Go Fast Bitx Stealth FX BOV
Vishnu Tuning Remapped OEM ECU
TXS (turboxs) FMIC
TurboXS Turboback w/Catpipe
TurboXS Racingpipe
WRX Tuner GT-Spec Header
GReddy Airinx Intake
Go Fast Bitx Stealth FX BOV
Vishnu Tuning Remapped OEM ECU
TXS (turboxs) FMIC
#15
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Join Date: Nov 2002
Location: Reno, NV
Posts: 18,369
Car Info: 1993/2000/2001 GF4 mostly red
The GC/GM chassis is not as stiff as the GD/GG chassis, but it is significantly lighter and as I said beofre, has more suspension options. But, I wouldn't suggest that someone give up their GDA to swap into a GC6. Just if you are starting from scratch.