Engine/Power - EJ25T (STI and 2006+ WRX) Discussions about the USDM 2006+ WRX and WRX STi 2.5 liter turbo flat-four.

JDM Impreza STI versus USDM IMPREZA STI

Thread Tools
 
Search this Thread
 
Old 10-14-2004, 03:55 PM
  #1  
Registered User
Thread Starter
iTrader: (38)
 
chochocho's Avatar
 
Join Date: Jun 2003
Location: San Ramon, CA
Posts: 1,236
Car Info: 91 legacy, 87 mr2, 17 forester xt
JDM Impreza STI versus USDM IMPREZA STI

hi all,

just wanted some engine info on JDM STI versus USDM STI. the size is different. what else? which one is more reliable, stronger?

thanks.
chochocho is offline  
Old 10-17-2004, 11:52 AM
  #3  
Registered User
iTrader: (5)
 
XkrazyAsianX's Avatar
 
Join Date: Jul 2004
Location: San Jose/ San Leandro
Posts: 3,300
Car Info: SGM 135i
actually .. it's not vtec ;. it's subaru's version of vtec. th avcs (active valve controle system) and it's better than vtec in that it's shifting the cam shaft all the time compared to the vtec which only shifts at high rpms.
XkrazyAsianX is offline  
Old 10-18-2004, 07:53 AM
  #4  
Father Time
iTrader: (4)
 
Double Phister's Avatar
 
Join Date: Sep 2004
Location: You're doing it wrong!
Posts: 6,699
Car Info: This aint a bag. It's a shipment.
Originally Posted by XkrazyAsianX
actually .. it's not vtec ;. it's subaru's version of vtec. th avcs (active valve controle system) and it's better than vtec in that it's shifting the cam shaft all the time compared to the vtec which only shifts at high rpms.
ah, but i-VTEC on the newer Honda vehicles has both the old style hi/lo cam and constantly adjusting cam angle timing. Most every manufacture now has some form of variable valve timing.
Double Phister is offline  
Old 10-20-2004, 03:55 PM
  #5  
Registered User
 
Dirty Sanchez's Avatar
 
Join Date: Sep 2004
Location: Cali
Posts: 40
Car Info: WRX STi 2004
Originally Posted by latinplaya64
usdm motor is a 2.5 vrs the jdm 2.0w/ verable timing electronicaly controlled (vtec)motor. Usdm redline 7000rpm vrs jdm 8200prm. email for more details
So would the JDM engine be better cuz of higher RPM?
Dirty Sanchez is offline  
Old 10-20-2004, 04:53 PM
  #6  
Registered User
iTrader: (1)
 
MVWRX's Avatar
 
Join Date: Aug 2004
Location: UCIrvine
Posts: 3,312
Car Info: '05 Crystal Grey Metallic WRX Sport Wagon
In terms of horsepower, how do they get more out of the 2.0JDM than the 2.5USDM? Or don't they? ...bigger turbo? ...higher compression?
MVWRX is offline  
Old 10-21-2004, 08:08 PM
  #7  
Registered User
iTrader: (1)
 
gordy's Avatar
 
Join Date: Nov 2002
Location: LA, 91355
Posts: 352
Car Info: '03 WRX WRB
Originally Posted by MVWRX
In terms of horsepower, how do they get more out of the 2.0JDM than the 2.5USDM? Or don't they? ...bigger turbo? ...higher compression?
jdm gas
gordy is offline  
Old 10-27-2004, 10:46 AM
  #8  
Registered User
 
Valaar's Avatar
 
Join Date: Jan 2003
Location: Monterey,CA
Posts: 164
Car Info: 2002 Evil Wrx
Originally Posted by gordy
jdm gas
Amen to that!
Valaar is offline  
Old 10-27-2004, 11:50 AM
  #9  
VIP Member
iTrader: (17)
 
Onizuka's Avatar
 
Join Date: Jul 2004
Location: Northern California
Posts: 3,969
Car Info: 04 STi
JDM gas & forged internals = cool, my tranny and engine won't break!

-GDO
Onizuka is offline  
Old 10-27-2004, 04:59 PM
  #10  
VIP Member
iTrader: (3)
 
GotBoost?'s Avatar
 
Join Date: May 2003
Location: SBAIC-South BayArea Impreza Club-Campbell, CA-Thur
Posts: 3,648
Car Info: 2003 PSM STi
Originally Posted by Onizuka
JDM gas & forged internals = cool, my tranny and engine won't break!

-GDO
errrr.....dude, your car is a USDM not a JDM......





also, Japan doesnt have SMOG laws to sidestep, if we didnt have to worry about smog, there would be a whole lot of 300+ hp 2.0L subys out there.


-T
GotBoost? is offline  
Old 10-27-2004, 07:14 PM
  #11  
Registered User
iTrader: (3)
 
Aithien's Avatar
 
Join Date: Dec 2002
Location: California
Posts: 176
Car Info: 2002 Subaru Impreza WRX
Originally Posted by GotBoost?
errrr.....dude, your car is a USDM not a JDM......





also, Japan doesnt have SMOG laws to sidestep, if we didnt have to worry about smog, there would be a whole lot of 300+ hp 2.0L subys out there.


-T
They have even worse laws compared to just smog regarding cars.
Aithien is offline  
Old 10-28-2004, 01:45 AM
  #13  
Dahveed aka Robin Hood
iTrader: (3)
 
Group B's Avatar
 
Join Date: Nov 2002
Location: Robbin' the Hood (Claycord)
Posts: 4,793
Car Info: (RIP) '04 STi Silver
Originally Posted by latinplaya64
by the higher redlimiter does creat more hp but loses torque which you really want more then hp
depends on what you want...

For the track (circuit) higher RPM power is better, and for drag racing, lower RPM Torque is better.

For an example of a street car meant for the track, do a search on the BMW E30 M3.

With our crap gas, the USDM STi needed another half liter, even though EVOs don't...
Group B is offline  
Old 10-28-2004, 01:49 AM
  #14  
Admin v2.0
iTrader: (9)
 
Imprezer's Avatar
 
Join Date: Nov 2002
Location: Alameda, CA, USA
Posts: 6,965
Car Info: 02 Black Legacy GT
I'd take JDM STi over US STi any day. Especially any variations of it with Spec C motor.

But then again, I am such a JDM *****...
Imprezer is offline  
Old 10-28-2004, 01:52 AM
  #15  
Dahveed aka Robin Hood
iTrader: (3)
 
Group B's Avatar
 
Join Date: Nov 2002
Location: Robbin' the Hood (Claycord)
Posts: 4,793
Car Info: (RIP) '04 STi Silver
JDM V7 has fully forged pistons, but I know the USDM STi doesn't, nor is the JDM V8 I believe...
Group B is offline  


Quick Reply: JDM Impreza STI versus USDM IMPREZA STI



All times are GMT -7. The time now is 10:40 AM.