Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Subaru WRX STI 2.5 aftermarket turb options

General Tuning Discussion

Forum Posts



Tech Articles

Discuss all things tuning in this section. News, products, problems and results. 

= Resolved threads


Hello everyone,

Customer is not happy with the performance and wants more power, something in the range of about 400 at wheels. I am new to WRX and want to know what turbo to select that fits with least mods. Also what to use for ECU flashing that is strait forward and works? COBB, ECUTec, .....

thanks in advance.

You can buy a variety of bolt on turbos from the likes of HKS and Garrett. I have used quite a few which have put out around 300kw at the wheels. It can be quite a push depending what fuel you're running on and what supporting mods are fitted to the vehicle.

I have used ECUtek, ECUedit and Opensource on most Subaru's with great results. All basically do the same, just different software. Although in some cases you can get additional features like ECUtek's race ROM features or speed density

Thanks Chris,

What size of turbo that gives 300kw? Pump gas is 95 octane in my country..

From memory I believe one of them was a HKS GT2835 Bolt on, although I could be wrong.

If Andre see's this he might be able to confirm if he remembers what we put on Alex's STi, Andre?

The Garrett GTX3071 is a great street turbo, Blouch make a bolt on version. Prob struggling to get 400whp though.

400WHP on 95 is going to be a challenge specially on a subaru

Gt3076 or bigger

Gt28 won't make 400WHP

Look for an efr turbo that's also an option

I tuned alot of different Subarus. All I can say, Borg warner wins all day! especially on Subarus!

Thank you all for the help.

Adrian, what size of Borg Warner is common for the WRX

EFR6758 or the smaller ones. Made 525hp at the engine with a EFR6758. Perfect for road/track cars.

What engine setup are u running? The 2.5l engines struggle from their thin cylinder liners. Without sleeving/close decking or at least pinning, the cylinder is most likely to crack. http://s944.photobucket.com/user/cnstman/media/EJ257/Cracked-Sleeve.jpg.html

Good headwork and de-squishing can help with you r95 octane fueling.

Blouch XT-R turbos are reasonable upgrade pnp turbos, but I'd also go the Garrett GTX or BW EFR route.

That looks like the engine had been dowelled incorrectly, they had taken too much out of the cylinder liner and weakened the walls, rather than shaping the dowels to fit into the space, with a shallow groove machined only to locate the dowel.

Those grooves are standard on these blocks, to be able to fit the head of the block bolt. Otherwise you won't be able to install it. It's common that they split at that weakpoint and you can't use pins over there for that reason. The ej257 engines suffer form those cracks already at 21-22psi boost over time. Even with a save tune without any knock...

Hi, we usualy sell tomioka racing 18g or 20 g turbo, very good performance, can be run on 91 octane fuels, you can reach 340 whp with 18g and 380 whp with 20g. Billet is the best option for lag, and twinscroll for 20g.

I am also a big fan of EFR turbos; I have a 6758 on my STi and 7064 on my S2000. If he's looking for a bolt-on turbo, I like the Blouch 2.5XT-R. Otherwise, there are lots of options when you rotate it. My 6758 is in the stock location, but does not use a factory style uppipe or downpipe.

Alex 182: set up is stock.

Blouch seems to be an attractive option since it is direct bolt on.

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?