2.5 STI (Hawkeye) power upgrades
 

Hi,

I have recently bought a 56 plate sti hawkeye. It is totally standard. My last Impreza was a WR1 which I loved and regret selling but at the time needs must.

Can anyone tell me what I can do to up the power a little as it is just too slow. My mates standard FQ340 just embarrasses me whereas the WR1 could sit with him. If I was to just change the exhaust and air filter would that make a difference? Do I need to get an ECU upgrade too and if I do what would I need to get?

I am changing the speakers first though as this car has the worst stereo system I have ever heard!!!

Any help would be appreciated.

Thanks

Laurence

Dunc at RaceDynamix can map that for £350odd.

I'd probably get a K & N or Cosworth Panel filter fitted 1st... plus if the budget allows a 3" exhaust system cat back or full decat if you are not worried about MOT issues.

That'll see you to around the 350bhp level

Totally agree, it sounds worse than what looks to be the same model that was in my 04 WRX!

Would it be possible to see gains without a new exhaust then? What would a remapped STI get?

with just a panel filter I think Duncan suggested 20-30bhp without changing the exhaust... the biggest difference would be throttle response and better drivability.

Mine now boosts 1.3bar with standard downpipe still in place... standard is 1bar I think

It would be comfortably over 300 with just a remap on that 56 plate and would be easily quicker than the WR1.

Get to Litchfields and get an LM400 turbo fitted.

A twin scroll turbo would be of absolutely no benefit whatsoever.

:norty: I might get saving!

I thought first time remaps were c£600?

Milltek with sports cat, Green panel filter, Ecutek remap. Well, those are the performance mods I plan when I get a Hawk Sti in the summer, along with Prodrive springs and Bluestuff pads, Prodrive grill and detangoed wheels!

:brickwall :brickwall :brickwall

O yeh I forgot that his car was UK. your are sort of snookered if you go for any more power you risk blowing your engine.

Immy

Because Hawk engine's are fragile?

nope £350 :thumb:

I have a 56 plate STI. Got an afterburner rear box and centre section, panel filter and remap and its a different car. Much smoother power delivery, much quicker and more responsive. The best way to describe it is third now pulls like second used to, forth third etc. It was by far the best thing I have had done.

Milltek 3" sports cat system on mine & Simota panel filter - open source map & 350bhp & 400lbft of Torque.

Bargain! Do you ever visit Edinburgh (for a fee)? Is it Ecutek remapping you do?

Where are you? Is 360/390 likely based on the mods I described?

If I carry out those mods and get 350bhp will engine cope ok? This car at the moment is just a little gutless. Thanks for all the replies, I am feeling a little better about it now. Anyone able to recommend a good exhaust that is louder than standard but not stupidly loud?? Would a prodrive exhaust be a good option or would that struggle to run 350bhp?

Yes was up in scotland mapping last week. Non ecutek.

360 is possibly just a little over the top but 390 lb/ft is easily acheivable.

Hawk and hatch due to the 2.5 lump even people who have swoped there Jap 2.0l engines for the 2.5 and stook with the Jap heads twinscroll turbo etc have had issues with the 2.5
Is that ECUTEK?

Non Ecutek - so what is it you do Dunc - I take it there must be some programme you use as a start point? Excuse my ignorance!

One more thing (ok, 2!) Dunc.

What would be gained from remapping a PPP 2006 Sti in terms of bhp and torque?

Had a look at your site (pretty good btw!) How did Drew get his Hawk Sti to 390bhp+?
Turbo swap?

Cheers

Andy

PPP sti should get to around the 340bhp mark and 380 lb/ft as they do not change the exhaust cats in the PPP on the hawk. With a good exhaust on, they will do better. (mine runs a miltek 3 inch decat system which is lovely - not too loud but flows great)

The software that I use has access to exactly the same tuning parameters that ecutek has and can add in some additional features too like launch control and flat throttle shifting to the standard ecu. Only that you do not have to pay the additional money for a license to ecutek.

Drew's had the standard turbo but full decat, 3 port solenoid, fuel pump and panel filter. To be fair I believe those rollers were a little optimistic on that day and nearer 370bhp is the right figure.

Cheers Duncan.

Am keen on the Milltek from what I have heard. Imagine I would get a Walbro, but is the 3 port solenoid necessary at this level? It doesn't actually effect the bhp/torque, does it?

So Drew might have expected 360/390 if he'd fitted a Milltek with a sportcat downpipe?

What brand of software is it you use?

thanks again

Andy

Taken from andy forest's Website !!!!

Personally I'd go for Level 4. Great increase in performance for the money without going tooooooooo deep. Lol ! The 321T turbo is a big favourite in the subaru world. Great turbo !!!!! But it really does depend on budget. In my opinion the best mod I did to my car was the GT spec gen II headers. Absolutely loved the sound. Not to everyone's taste though as it loses the burble higher up in the revs and sounds a bit more like a big bike, but you still have the famous Scooby burble down low. If you are for changing the exhaust (which being realistic, if you want anymore power its the first thing you have to do), I definitely go for the headers...... but get the right one's, not the cheap copies or you will end up welding them forever and a day.

Hope this helps mate !



06-09 STI UK



Level 1 290-300 bhp

Sportscat Exhaust System
EcuTek custom remap (compares to PPP)


Level 2 340-360 bhp

Full Decat turbo back 2.5 " or 3” bore
Walbro 255 l/hr uprated fuel pump (not reqd on 08/09)
EcuTek custom remap
K+N panel filter (cold air induction required on 08/09)


Level 3 360-390 bhp

Full Decat turbo back 3” bore
Walbro 255 l/hr uprated fuel pump
K+N panel filter (cold air induction required on 08/09)
Ecutek custom remap
Fuel Lab turbo specification fuel pressure regulator with fitting kit & gauge
AFP 5-20G Ported Exhaust & wastegate sized to 2.5 and machined to suit
NGK uprated spark plugs


Level 4 400-420 bhp

Full Decat turbo back 3” bore exhaust system
Tubular exhaust headers and flow matched uppipe
Walbro 255 l/hr uprated fuel pump
EcuTek custom remap
Custom Cold air induction
650cc Injectors
AFP 321T custom turbocharger with fitting kit
NGK uprated spark plugs


Level 5 420-460 bhp

Full Decat turbo back 3” bore exhaust system
Tubular exhaust headers and flow matched uppipe
Walbro 255 l/hr uprated fuel pump
EcuTek custom remap
Custom Cold air induction
650cc Injectors
Fuel Lab turbo specification fuel pressure regulator with fitting kit & gauge
AFP 321T custom turbocharger with fitting kit
NGK uprated spark plugs
AVCR boost controller
Optional FMIC
Uprated clutch
NGK racing 8 spark plugs

Note On 06/09 WRX/STI 2.5 short engines the pistons run very tight bore clearances. On Level 4 and above we recommend a forged piston upgrade. The forged piston upgrade is also recommended for level 3 upgrages if used for sustained high speeds or if used regularly on track.
Level 5 we also recommend steel conrods, ARP head studs and uprated head gaskets.

PLEASE NOTE

We have included the tuning section us a guide to what we consider to be the most cost effective steps during tuning. This has been compiled with the benefit of experiencing hundreds of upgrades. There are other parts/turbos that can be substituted but the listed parts we have found to give the most consistant results over many installations.

Your own ideals may vary depending on the parts you may currently have fitted.

Our suggested levels are compiled to mimise incompatible components, it is not ideal to fit a turbo that your fuel system cannot support for example,

We do not do parts fitting here so I can't give you a full price, the components in the tuning stages are listed in order to allow you to select the most cost effective route to power and in turn allow us to achieve the best results from your car.

Our core business is ECU Custom Mapping and Hybrid turbocharger design/building. We are not here to try and sell you the parts with the biggest profit margin, we can however supply (for local collection or mail order) all the tuning parts listed if required. Optionally you can source them yourself or arrange for the garage doing the fitting to supply them. The individual parts prices can be found on the website on their respective pages

We can recommend specialist garages within a 100 mile radius that work with us on a regular basis to fit the parts if required. These garages have been specially selected as places that are very experienced specifically with Subarus and work on a daily basis with this type of car. We recommend them as we know they will look after your car and their attention to detail will ensure maximum reliability. It is perfectly safe to have the parts fitted and then drive to us off boost (this still allows cruising at 70mph) for final setup and custom mapping. We have had cars drive over 400 miles to have this done.

Predicted BHP figures are approximations, our section on “rolling roads” explains in some detail why it is impossible to give exact figures.

You should add complete engine rebuilt to that list if you try that mod list on a 2.5 hawkeye.

The standard pistons will not take that or are very unlikely to take that for long.

On a hawkeye sti I would stop at level 2 unless you are prepared for an engine build or can put some forged pistons in beforehand.

Level 1 is a bit conservative also. :) should be comfortably over 300 with a pump, filter added :)

Those power levels that Andy wrote are for the 2.0 sti and dont apply on the 2.5 IMO

interesting read. looking to do mine in the (hopefully) near future.

although nothing to extreme just exhaust mapping and supporting mods.

thanks:thumb:

Hi Laurence,
I have an 07 2.5 Hawkeye Sti, and as soon as it came out of warranty I took it to Richard Bulmer's Tracktive Solutions, and had it fitted with a 3" Milltek exhaust, with a 100 cell sports cat, an uprated fuel pump, panel filter, and spark plugs.
Richard then remaped it in the region of 350 bhp/390 ft lbs of torque, which totaly transformed the car.
I can ashore you that with the torque alone, it now has, and without the need to use its maximum revs., you will out pace the WR1 you had, also I doubt the FQ340 will cause you any further embarrassment.
It has such a smooth power delivery, which makes for a very fast, superb road car.

:thumb: