2.5 N/A to Turbo

TdotSubie · Post by **TdotSubie** » Fri Feb 16, 2007 5:33 am

Im in the process of buying a new car, and I'm trying to decide between a 94 SS auto, or a 97 GT 5spd (legacys obviously). My question is if anybody knows wether or not the 2.5 N/A motor can be boosted easily, and if so how much is safe? I had a 93 SS auto and the only thing I didn't like about it was that was an auto, so this time around I really want a 5spd. Another option is maybe a 5spd swap in the SS. Thoughts?

gto7419 · Post by **gto7419** » Fri Feb 16, 2007 5:49 am

The 2.5 can be boosted just as easily as any other n/a motor. the problem you will run into though, is the rods/crank are not forged, you have a higher compression motor, your ecu will have advanced timing where as a boosted application may need the timing retarded.

Basically, the stock rods in the 2.5 n/a cannot handle the extra torque a turbo adds. On top of that, you will have to deal with adding fuel and retarding the ignition. You might also want to get a set of pistons made for a turbo as the n/a pistons are higher compression.

I would personally do the tranny swap and upgrade the turbo on the ss....

Danny

555BCTurbo · Post by **555BCTurbo** » Fri Feb 16, 2007 6:23 am

Actually, all Subie EJ cranks are forged...and most of the rods too...

Many people have turbocharged the EJ25's, but I honestly don't see the reason you would want one over an EJ22T...

An auto to manual swap is very straight forward, much less time and money than a turbo EJ25 project

Kelly · Post by **Kelly** » Fri Feb 16, 2007 7:05 am

NA22s turboed suck.

555BCTurbo · Post by **555BCTurbo** » Fri Feb 16, 2007 7:11 am

He is talkin NA 2.5's Kelly...

But I am sure that's what you meant

(Kelly has expressed his disdain for turboed EJ25's to me in the past lol)

gto7419 · Post by **gto7419** » Fri Feb 16, 2007 7:27 am

555BCTurbo wrote:Actually, all Subie EJ cranks are forged...and most of the rods too...

Many people have turbocharged the EJ25's, but I honestly don't see the reason you would want one over an EJ22T...

An auto to manual swap is very straight forward, much less time and money than a turbo EJ25 project

Hmmm - I thought we were the only lucky ones!!! Are the rods in the 2.5 n/a forged also?

douglas vincent · Post by **douglas vincent** » Fri Feb 16, 2007 7:39 am

Kelly is currently "in a snit"

But I still love him.

azn2nr · Post by **azn2nr** » Fri Feb 16, 2007 7:56 am

pistons are the difference betwenn 22t and 25x. they all use the same rods which can withstand the power.

turboed subie na's hardly make power off the shelf turbo style. their very finiky when it comes to this sort of thing

Kelly · Post by **Kelly** » Fri Feb 16, 2007 9:05 am

Wow, I was so blinded by rage about my dog eating my pizza.

NA25's are grunty when done correctlly, but grenades when not.
NA22's suck.
Neither are fast.
And yes, I'm a bit "snitty"

92ss satinsvoice · Post by **92ss satinsvoice** » Fri Feb 16, 2007 11:05 am

get some stock turbo pistions, rods and call it good on the bottom end.

for a n/a 22 that is..

justin the subie · Post by **justin the subie** » Thu Mar 29, 2007 4:53 am

my '92 touring wagon was an automatic... i think many people in this forum already have had this convo with "laurel the queen" when she was getting it done.... the swap looks and works very very good... i just hooked up the neutral safety switch to the alarm and remote start and it works sweet as well... kudos to whoever did my AUTO2MANUAL swap!!!

[img]C:\Users\User\Pictures\2007-03-27\IMGP0239.JPG[/img]

555BCTurbo · Post by **555BCTurbo** » Thu Mar 29, 2007 7:22 am

Pacific Import Auto did your auto > manual swap...

justin the subie · Post by **justin the subie** » Fri Mar 30, 2007 5:41 am

hey thanks man!!

im tryn to get as much info on this car as possible.. do u know the previous owner(s)??? i have many questions about my car, like what is this wire harness all tucked up behind my radio??? it looks like a computer monitor plug... what turbo ive got... neway thanks for the info.. much appreciate

555BCTurbo · Post by **555BCTurbo** » Sat Mar 31, 2007 12:04 am

I knew Laurel, before she decided to go totally apeshit on me and not be my friend...

I don't know a whole lot about the car, but I rode in it when it was Auto, and I know it has a TD05 Turbo and an AWIC...and it was REALLY slow!!

It's a nice car, take good care of it...

and no big hood scoops!!!

Oh...that computer monitor plug is most likely a select monitor cable...search to find out about what that is

justin the subie · Post by **justin the subie** » Sat Mar 31, 2007 1:40 am

i love the car.. its been great. im planing on changin the turbo soon.. do you think its still got a td05? is that a 05 sti turbo? what 1 should i replace it with? vf39.. is that the same thing cuz i got no idea.. ive been reading as much as possible for a couple months and it sounds like the vf39 ballbearing is the best bolt on replacement.. but im readin that i should change injectors at the same time.. whats the best plug and play.. or something fairly simple. im pretty good with subarus. ive and many.. thanks again

gto7419 · Post by **gto7419** » Sat Mar 31, 2007 2:36 am

That is a damn nice downpipe...

MY99 2.5GT · Post by **MY99 2.5GT** » Mon Apr 09, 2007 9:14 pm

VF39 is the stock STI turbo but it isn't ball bearing.

The VF34 is an older JDM stock STI turbo and is ball bearing. I was just reading about someone that did VF34 swap into their ss.

You will definitely need to swap injectors. I would think the STI side feeds would work. I bought a set of 740cc sidefeeds from a good seller on ebay for under $300.

Brad

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2.5 N/A to Turbo

2.5 N/A to Turbo