Turbo 2.5i
#1
Registered User
Thread Starter
Join Date: Feb 2007
Location: Pleasanton
Posts: 115
Car Info: 2.5i N/A
Turbo 2.5i
OK so i'm going to get flamed big time for this, but what ever.
Let me start off by saying the newer 2.5i has no aftermaket and i'm getting kind of tired of that. I WANT BOOST. And no i don't want to sell my 2.5i and save for a wrx.
I'm looking for information on what i should use to peice together a turbo kit. i may just need all new exhaust from an 05 rs but i need ur imput.
thanks
Let me start off by saying the newer 2.5i has no aftermaket and i'm getting kind of tired of that. I WANT BOOST. And no i don't want to sell my 2.5i and save for a wrx.
I'm looking for information on what i should use to peice together a turbo kit. i may just need all new exhaust from an 05 rs but i need ur imput.
thanks
#2
why would you need the exhaust from an RS? you'd need the exhaust mani/up/dp from a WRX and you might also want to lower the compression...so that means engine internals...
if you don't plan on running more then 4-5psi then you should be fine with just the parts from a WRX but if you want more...lower cr pistons and forged rods should do it...other then that you need to also tap the oilpan and such to run oil feed/return lines for the turbo.
also you'd need a better fuel pump (i think a lot of people go with the walbro or whatever it's called) and fuel injectors (either wrx or sti)...you can save some money by not buying the turbo cross member and just notch the one you already have to fit the UP. I'm probably forgetting something...obviously you'd have to get a fmic, i think they still sell replica/cheap ones on ebay (obx?)...pretty much everything needed to turbo an RS goes for the 2.5i...really the only difference with the '05rs and '06-'07 2.5i engine is the ecu and avls
if you don't plan on running more then 4-5psi then you should be fine with just the parts from a WRX but if you want more...lower cr pistons and forged rods should do it...other then that you need to also tap the oilpan and such to run oil feed/return lines for the turbo.
also you'd need a better fuel pump (i think a lot of people go with the walbro or whatever it's called) and fuel injectors (either wrx or sti)...you can save some money by not buying the turbo cross member and just notch the one you already have to fit the UP. I'm probably forgetting something...obviously you'd have to get a fmic, i think they still sell replica/cheap ones on ebay (obx?)...pretty much everything needed to turbo an RS goes for the 2.5i...really the only difference with the '05rs and '06-'07 2.5i engine is the ecu and avls
Last edited by zavier; 06-28-2007 at 05:27 AM.
#3
im on the same page as you. if you look at the forum 'turbo kits' in this section, that has pretty much everything you need and you can run up to 8 psi boost according to the vendor, but that seems a little high, 6psi, no problems.
https://www.i-club.com/forums/aftermarket-forced-induction-turboed-factory-na-engines-62/turbo-kits-164612/
they say its about 100 hp extra. im on the same page as you.
https://www.i-club.com/forums/aftermarket-forced-induction-turboed-factory-na-engines-62/turbo-kits-164612/
they say its about 100 hp extra. im on the same page as you.
#6
except there are plenty of people running 6-8psi stock block...but that's cool...also the thread below this one from vivid...that dude said with a tune he was running a lot more...so no the MAX is not 4psi...but close
also if you used the STi short block with your heads you could run a lot more then 12psi...the reason the NA motor is so limited is because of it's high compression 10:1 + 6psi is a lot...there was a thread on nasioc that showed how to calculated it's "effective" psi...also the pistons in the stock block are not as strong as in the STi...so if you had the forged rods, the stronger pistons, 8.2:1...you could run a lot more boost
also if you used the STi short block with your heads you could run a lot more then 12psi...the reason the NA motor is so limited is because of it's high compression 10:1 + 6psi is a lot...there was a thread on nasioc that showed how to calculated it's "effective" psi...also the pistons in the stock block are not as strong as in the STi...so if you had the forged rods, the stronger pistons, 8.2:1...you could run a lot more boost
#7
Registered User
Join Date: Jan 2007
Location: Southern Colorado
Posts: 156
Car Info: 07 impreza 2.5i
except there are plenty of people running 6-8psi stock block...but that's cool...also the thread below this one from vivid...that dude said with a tune he was running a lot more...so no the MAX is not 4psi...but close
also if you used the STi short block with your heads you could run a lot more then 12psi...the reason the NA motor is so limited is because of it's high compression 10:1 + 6psi is a lot...there was a thread on nasioc that showed how to calculated it's "effective" psi...also the pistons in the stock block are not as strong as in the STi...so if you had the forged rods, the stronger pistons, 8.2:1...you could run a lot more boost
also if you used the STi short block with your heads you could run a lot more then 12psi...the reason the NA motor is so limited is because of it's high compression 10:1 + 6psi is a lot...there was a thread on nasioc that showed how to calculated it's "effective" psi...also the pistons in the stock block are not as strong as in the STi...so if you had the forged rods, the stronger pistons, 8.2:1...you could run a lot more boost
i know i could run more boost with a STi short block and my 2.5i heads. but for daily driving, 12psi will be plenty fast for me, and if i need to up the psi, a boost controller will fix that
#8
Registered User
iTrader: (1)
Join Date: May 2007
Location: flashing to pass in your rearveiw
Posts: 343
Car Info: was a 02 wrx now a beast
all the 06-07 blocks from what I understand are the ej257 semi closed deck block but with high compresion pistens so they sould be alot beter than the 2.5 rs-turbo's
#9
well it's not the EJ257 bottom end...the WRX has the EJ257 bottom end like the STi...but the 2.5i has an EJ253 bottom end...non-forged pistons or rods...also it's open deck...that much is known, and if it's open deck it isn't en EJ257 bottom...
the new 2008 WRX motor is open deck (weird...the 2.0L was open, then it was the STi semi-closed, and now it's back to being open) as well as the 2.5i...so the newer 2008 WRX and 2.5i might share the same bottom end
the new 2008 WRX motor is open deck (weird...the 2.0L was open, then it was the STi semi-closed, and now it's back to being open) as well as the 2.5i...so the newer 2008 WRX and 2.5i might share the same bottom end
Last edited by zavier; 09-26-2007 at 08:11 AM.
#10
Registered User
Join Date: Nov 2002
Location: Guaynabo, Puerto Rico
Posts: 4
Car Info: 1999 RS-T Silver Bullet
#11
Registered User
iTrader: (1)
Join Date: May 2007
Location: flashing to pass in your rearveiw
Posts: 343
Car Info: was a 02 wrx now a beast
I will have to look more into the 2.5i's sharing the same block the guys that told me that are prity reputable. not that I am doubting what you know but I just want to see for my self. if you could I would love you to point me to something that might show that info.
thanks man
Tristan
thanks man
Tristan
#12
Registered User
Join Date: Oct 2004
Location: Monticello MN
Posts: 271
Car Info: 1996 impreza 60 trim, 8psi 201 whp, 213 tq 200k mi
this comment lacks horribly, i run, and have been running 9 psi on my n/a 2.2 for WELL over a year 40K miles, with no more management then a RRFPR and bigger injectors
#13
Registered User
Join Date: Oct 2004
Location: Monticello MN
Posts: 271
Car Info: 1996 impreza 60 trim, 8psi 201 whp, 213 tq 200k mi
well it's not the EJ257 bottom end...the WRX has the EJ257 bottom end like the STi...but the 2.5i has an EJ253 bottom end...non-forged pistons or rods...also it's open deck...that much is known, and if it's open deck it isn't en EJ257 bottom...
the new 2008 WRX motor is open deck (weird...the 2.0L was open, then it was the STi semi-closed, and now it's back to being open) as well as the 2.5i...so the newer 2008 WRX and 2.5i might share the same bottom end
the new 2008 WRX motor is open deck (weird...the 2.0L was open, then it was the STi semi-closed, and now it's back to being open) as well as the 2.5i...so the newer 2008 WRX and 2.5i might share the same bottom end
#14
Registered User
Join Date: Jan 2007
Location: Southern Colorado
Posts: 156
Car Info: 07 impreza 2.5i
i said ANY [READ: ANY] N/A not just on subaru's!!! (on a cavalier, with stock block can only handle 4psi maxed) 4psi is safe on any N/A, anything OVER 4psi, you're playing with the car gods and the money gods!
05 Impreza engines are as followed, RS/2.5i = EJ253, WRX(06+) = EJ255, STi EJ257
02-05 WRX/04 STi had the EJ205/7.
05 Impreza engines are as followed, RS/2.5i = EJ253, WRX(06+) = EJ255, STi EJ257
02-05 WRX/04 STi had the EJ205/7.
#15
i wasn't claiming the WRX has an STi motor in it...i was saying the bottom ends were from the same mold...i also was not claiming the WRX has the same internals...cause the WRX runs a 8.4:1 cr and the STi runs an 8.2:1 cr...so right there the difference is shown.
i never said the WRX was not an ej255 nor did i said it was a complete ej257...i was referring to the bottom end...o also the heads on the WRX and STi are different. Running different cam profiles even though both now have AVCS...whatever though right? Also it was more so a comparison on the fact that both the WRX and STi are semi-closed where the old WRX was open...but forget it...
and Vizzionz thanks for the history lesson...im sure that was a useful waste of time on your part
also im not even sure why we are talking about this...turbo'ing a car has nothing to do with open, semi-closed, or closed design. The old WRX motor was open...the 2.5rs/i is open...but that is where the similarities end. putting a turbo on an open deck will not cause problems, yea sure people have said "it will warp the cyl walls" which is not the case, at least not with these motors. if you wanna turbo an rs/i you need to make sure you keep the boost low unless you get a good tune, i've seen rs's run 12psi on a good tune for over 2yrs and no problems but normal motor issues (**** i've already blown a 2007 2.5i and it wasn't turbo'd haha)
Last edited by zavier; 10-17-2007 at 06:23 AM.
Thread
Thread Starter
Forum
Replies
Last Post
JDMGC8
Used Aftermarket Car Parts For Sale
7
05-29-2009 08:07 PM
fuzzycuffs
Engine/Power - EJ20T (pre-2006 WRX and JDM)
8
02-08-2004 06:38 AM
singsing
Engine/Power - EJ20T (pre-2006 WRX and JDM)
6
05-24-2003 03:19 AM
samurai
Engine/Power - EJ20T (pre-2006 WRX and JDM)
7
01-16-2003 05:46 PM