Have 250t. And turbo gear. Should I mix?

[BLSTIC]

Pretty much the only parts I don't have are the dump pipe and turbocharger, everything else I can either make, adapt, or have anyway.

What's the compression ratio of the 250T? I won't do it if I have to crack the engine. The plan is a 40% increase in power (which will get me to twin-turbo kind of pace), which I need at least 7 psi for.

[BLSTIC]

Just checked it. It's 9.5:1 apparently. I should be able to run 7psi on that much compression if I'm careful with tuning.

has anyone done this?

[Guest keltik]

Nope and i dont think most people would. I know they can turbo the EJ22 and EG33 out of the box, what compression do they run?

[BLSTIC]

early (pre 97) sohc EJ22's run 9.5, later run 9.7. Lineball with the EJ25 DOHC compression. Can't find DOHC information.

EG33 runs 10:1.

How much boost do they shove through the EG33?

[Glen]

With the rate the damn things do head gaskets in at in NA form I wouldn't be putting any more pressure in there.

[DRFVDR]

 Glen said:

With the rate the damn things do head gaskets in at in NA form I wouldn't be putting any more pressure in there.

+ 1 zillion

sorry they not that reliable stock

[Old Skool Subbie]

 BLSTIC said:

early (pre 97) sohc EJ22's run 9.5, later run 9.7. Lineball with the EJ25 DOHC compression. Can't find DOHC information.

EG33 runs 10:1.

How much boost do they shove through the EG33?

Factory EG33 they dont run much more than 3psi or less on for supercharger or turbo??

Im trying to find what the normal numbers most run on factory blocks

can be unreible ( saying that one or two have used them and still going ) Unless they are fully rebuilt to cope with the higher presures

[nzkaosnz]

6-7pound on remapped ecu is pretty common.

i say do it - then if it breaks, fix it with bigger and better

Head gasket easy fix. Especially if ur mechanical enough to make own turbo setup.

250t headers will bolt directly to subaru turbo uppipe.

250t is same body as GTB, so will have clearance for downpipe.

if you got a turbo, mounts, TMIC from a wrx/older legacy - should pop straight on.

maaaaay need a new gearbox xmember, actually... no... the stock exhaust goes roughly where the turbo downpipe goes anyway

the biggest issue will be oil/water feed/return, not sure if the 250t heads have provisions for them... they are probably there, just need drilling/tapping.

and then youll need an a/m ecu.

if you want a stock sti downpipe (ex sti type r), i have one in tauranga...

[Guest boostin]

I've been thinking about this for a while. I say do it, and just run wastegate spring pressure.

[nzkaosnz]

 nzkaosnz said:

6-7pound on remapped ecu is pretty common.

whoops - forgot to say eg33 there.

[BLSTIC]

I have a complete RS/WRX hybrid engine here to rip bits off...

On second thoughts... for sale section...

[mikey]

Did you go ahead with this? I've been thinking about it too. I have a spare EJ25 which needs a rebuild so I could build it up with higher spec rods/pistons and give it a go.

[funkytown]

you probly better of just getting the later ej257 motor and doing it properly..

if you had a stock 250t block i would lend a hand to turbo that factory sucker for lolz...

[mikey]

Yep it's a stock 250t engine. It's got a bent valve and has possibly soft seized. I haven't pulled it apart yet. If I did rebuild it I guess the cheapest route would be going to pick-a-part a pilfering the down pipe, turbo, inter-cooler from a GT?

[DRFVDR]

the 250t engines are bad for blowing head gaskets so turboing one certianly would not help this situation

[ReubenH]

 boostin said:

I've been thinking about this for a while. I say do it, and just run wastegate spring pressure.

Yep, i vote do it. If you kill the engine, boohoo, they can be replaced for dirt cheap through the right channels. I Picked up an EJ22E for $400 including GST at strongs the other day. That's cheaper than the average rocker cover job at a workshop. I haven't bought a 25D yet, but hey, who says you gotta replace it with another 25D?

As for the chassis, 250T's are basically GT chassis's. It won't take allot at all to get through compliance if you need to do that.

[ReubenH]

 nzkaosnz said:

250t headers will bolt directly to subaru turbo uppipe.

250t is same body as GTB, so will have clearance for downpipe.

if you got a turbo, mounts, TMIC from a wrx/older legacy - should pop straight on.

Oh yeah, i forgot, the engine crossmember (and maybe gear box member) are turbo too. Those 250T's were just BEGGING to get turbo'd, honestly.

[Guest]

hey, i glanced at this thread and i got convinced to do a project 4 250t. Would any one please help me make a list of what to get/buy to turbocharge ths engine? I would like to DIY it. Should i worry about changing cranks, pistons,rings,stuf like that?

[dubbedup]

 marshelo said:

hey, i glanced at this thread and i got convinced to do a project 4 250t. Would any one please help me make a list of what to get/buy to turbocharge ths engine? I would like to DIY it. Should i worry about changing cranks, pistons,rings,stuf like that?

quick list,

turbo, uppipe, downpipe, ex manifold, oil lines/water line in and out, banjo bolts intercooler. some kind of ecu mod/adaption

[ReubenH]

And you gotta tap an oil return hole into the back of the head. That'll probably be the hardest part...

Nothing says you couldn't get creative though does it, return the oil somewhere easier?

[DRFVDR]

Alot of turboed vehicles have the oil return going straight into the sump,I have done this when adding turbos to a non turboed diesel

[Guest]

Shot for that list. So the tapping is the hardest bit huh? I'll give it a shot but carefully Thanks man

[ODB]

Dont do it.

Buy a factory turbo model. You will be much happier in the longrun and the car might retain some spec of its value but a self-made turbo wont sell for nix.

[mikey]

Don't listen to that fool. Doooo eeeiitt.

[Swindog]

 ReubenH said:

And you gotta tap an oil return hole into the back of the head. That'll probably be the hardest part...

Nothing says you couldn't get creative though does it, return the oil somewhere easier?

Tap into the sump as a return.