Is it possible to get 400hp out of an EJ257 block matched to standard heads off a '99 UK Impreza using a TD05 20G turbo?? My current turbo is showing signs of tiring so im thinking this will be a good time to upgrade, but im still running the standard 2 liter UK engine so will need to swap that too. Im on a tight budget so thats why im choosing the 257 and the TD0520G as they seem to be the cheapest options.

My current relevant mods are:
Front mount intercooler,
Walbro 255 fuel pump,
Aeromotive fuel pressure reg,
Induction kit,
Stainless headers and up-pipe,
VF29 turbo,
3" de-cat downpipe,
Blitz NUR Spec R rest of exhaust,
Ecutek Tek 3 map,
Twin plate carbon clutch,
light weight flywheel,
PPG gearset.

I know the gearbox and clutch can handle the change, but with it being a UK model is there anything else I should be worried about like the diffs? Also what size injectors do people think i'll need, 550's?? Any advise welcome, thanks.
Shane.

 

yes give or take a little and if you use a non-china sourced 20g.

740cc injectors needed..

worth changing the pistons on the ej257 the standard ones are a weak point.

the 2.5 and 20g make for a rapid road car imho
Simon

 

550's will be fine for 400hp

 

550s on 2.5 will be marginal.. if he needs to buy some, better to just get the 740s..

 

For the difference in price might aswell go for the 740's, the 550's will be able to cope but only just.

Better to get slightly bigger as long as you get them mapped correctly. That way is saves changing the injectors again when you up the power further down the line, and you will no matter what you say now you'll be adding more and more and more ha ha ha ha ha

 

The 20G was coming from Taiwan or somewhere, £500 sounded tempting, guessing there no good? I'll get one from a reputable UK company then. And if I can scrape the extra together I'll get some forged slugs and rods while im at it. Other wise it will only be coming out again next year for a re-build when I want more power.
Will the rest of the drivetrain handle it?? Thanks for the advise.

 

Something else I need to add to this is do the heads need modifying or can you just bolt them straight on??

 

They will bolt straight on, best using arp head studs.