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After careful consideration and debate...

Featured Replies

...I will be swapping out the EA82T and RX transmission for an EJ251 and 2003 WRX transmission.

 

The engine will be modified ofcourse:

 

Delta 'mild' cams (possibly the race ones depending on the specs).

EJ257 (STi) oiling system (oil pump/pan/sump/baffle/cooler/waterpump).

I might use the EJ205 intake manifold with ported TGV housings (aka TGV deletes) otherwise, I'll port match a stock EJ251 manifold.

AEM EMS for 2002~2005 WRX will be used to run the engine. That way I have total control over every aspect of the engine...and *IF* i decide to drop in a turbo engine later, it will be some simple retuning.

I'll be using the Borla style header and a high flow cat with a not-too-loud 2.5" catback system.

And finally...I will find some way to make the AC work as if stock.

 

As for the transmission:

OBX Helical front LSD.

1st and 2nd gear will be upgraded to the USDM Legacy GT 5MT gears.

3rd-4th will be 06 USDM WRX.

5th will remain stock for 2002~2005 USDM WRX.

Center diff stays stock.

The rear output reduction gears will be changed from the 1.1:1 to 1:1 so I can keep my 3.70 LSD rear diff that is stock for the RX.

 

Why 2.5 N/A thats slightly built? Reliability. I have all the parts (except the cams) and it will be VERY acceptably quick per the cost invested. Did I mention it will be reliable? Reliability is the KEY factor here. Oh, and no turbo lag. This setup *should* put down around 145hp/145tq to the wheels....maybe more.

 

I have a repaired water pipe for the EA82T thats in the RX...I'll finish this engine off after it hopefully makes some power on the dyno...then it'll be swap time.

Sounds like a good build... it will be quick.

Matt Monson is the undisputed master of the 2.5 N/A as far as I know... here are some threads and he did indeed get just over 150 HP at the wheels...

http://www.awdpirates.net/phpBB2/viewtopic.php?t=11557

http://forums.nasioc.com/forums/showthread.php?t=595740&highlight=dyno

 

I built mine for reliability, to get less EA82T and for MPG baby! I used the 3.9 gears (96 imp out tranny with converted LSD using EA series parts) and I have an JC sports intake and a Ebay crank pulley.... and very ghetto rigged exhaust(soon to be less rigged) Anyway I get about 30 MPG beating the snot out of it AND it'll run a 15 second quarter at 6000+ feet.:banana:

 

EDIT: P.S. save yourself the headache and if you do decide to turbo... ditch the N/A block... no really.. it cannot take it for very long.

  • Author

I've got spare EJ257 shortblocks laying around...so when i do turbo, one of those go in.

I'd do a little checking about the 03 wrx tranny. Everything I've read ahs said they had a 3.90 front final. And after the 06 year they switched to a 3.70.

  • Author

No, its all WRXs are 3.70 in the USA. Thats why I chose it.

 

Its the rear reduction BS that puts the rear ratio at 3.545

Good to know that Will.

 

This sounds like it should be a good running little beast.

umm Will your math don't add up..if a wrx has a 3.7 front diff and a 3.545 rear diff then that results in an aprox 1:1.04 center not a 1:1.1..a 3.9:1 front and 3.545:1 rear DOES however result in a 1:1.1 center..unless my math is wrong...so either the wrx doesn't have a 1:1.1 center or the rear final drive isn't 3.545 or the front diff isn't 3.7...

I've widely read that the USDM wrx has 3.9:1 front 1:1.1 center and 3.545 rear before '06

umm Will your math don't add up..if a wrx has a 3.7 front diff and a 3.545 rear diff then that results in an aprox 1:1.04 center not a 1:1.1..a 3.9:1 front and 3.545:1 rear DOES however result in a 1:1.1 center..unless my math is wrong...so either the wrx doesn't have a 1:1.1 center or the rear final drive isn't 3.545 or the front diff isn't 3.7...

I've widely read that the USDM wrx has 3.9:1 front 1:1.1 center and 3.545 rear before '06

 

After reading this I thought I'd verify...

 

http://www.cars101.com/subaru/impreza/impreza2003.html

 

Just before half page it lists the WRX final drive as 3.90. It doesn't make mention of the reduction that we all know is there at the rear.

 

And to confuse you more...

http://www.cars101.com/subaru/impreza/wrxsti2007.html

 

This page for the 07's says the wrx final drive is 3.0:1 and the STi is front 3.90, center 1.1:1, rear 3.545.

  • Author

I give.

 

I must have been looking at an 06 FSM thinking it was an 02~05 FSM.

 

In that case, I'll just take the 4.11 RP out of that legacy transmission I have, and swap the 4.11 RP out of the RS diff into my RX diff.

 

That way I've got a 4.11 'built' transmission.

 

Or I could find a 3.90 rear.

  • Author

Oh snap, this just in: Ive got a 3.90 rear R160 diff in t3h garage. :banana:

what are you doing with the ea82t bits when you are done with the swap?

 

i cant wait to see what kind of monster you end up with afterwords.

  • Author

JWX is getting all the EA82 related items.

  • Author

Scratch all that.

 

I recently traded in my 05 RS for an 04 WRX. WRX will be an STX/STU car...the DD and reliable.

 

That means the RX will stay EA82 since I will not have to rely on it daily. *off to get forged pistons*

JESUS H CHRIST ON A STICK MAKE UP YOUR MIND ALREADY!!!!!11111!1111 :-p

JESUS H CHRIST ON A STICK MAKE UP YOUR MIND ALREADY!!!!!11111!1111 :-p

 

basically

  • Author
JESUS H CHRIST ON A STICK MAKE UP YOUR MIND ALREADY!!!!!11111!1111 :-p

 

 

:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

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