Dan-

Hey all, this a question for my old man he owns a wrx-s which i belive to be a prodrive special?

its got 255 bhp as standard at the moment, what the best way to go about getting it up to around 300?

would he need to buy, intercooler, injectors, turbo?, fuel pump, pannel filter. will anything else be required

many thanks

mattygg

What reg is it, as if its a Blobeye one, i believe the PPP pack gives it about 265 bhp

http://www.prodrive.com/up/03MY%20WRX%20PPP.pdf.

Other than that, you can prob just get it remapped to near 300 bhp

Shaks-STI

iTrader: (7)

Its a Hatchback mate.


To OP:
Speak to a mapper.

Shaks-STI

iTrader: (7)

Some good info for you here mate

https://www.scoobynet.com/scoobynet-...-any-good.html

Dan-

Thank guys! Really think just a map should see a noticeable gain?

Gigsy

Possibly won't gain much in terms of BHP TBH - driveability should improve a little though.

Not 100% sure what top wack on a hatch is but I'd imagine it's pretty similar to a Hawk 2.5 so realistically, you'll be limited by the stock turbo - which means that if you want to hit 300+ BHP, you'll need to upgrade.

stevie1982

iTrader: (16)

Decat pipe, uprated panel filter and a remap should see a healthy gain. Speak to a few companies such as API and a mapper such as bob ralwe, they will point you in the right direction depending on budget and desired use.

Side note though if it'd under warranty still and you go for it you will lose the remaing cover.

Gigsy

On a standard car, for sure but the car already has the PPP installed so any gains would be lessened. If he wants more power over the current set up, he really needs to start thinking about a turbo upgrade IMHO.

stevie1982

iTrader: (16)

Ppp from memory is the centre cat removed if not the down pipe and the centre is left in place so doing a decat will only be a benefit, it also from memory an uprated fuel pump, so I stand by what I say full Decat, panel filter and a remap. Remember the standard Ppp map I would think would still be at a standard boost of what 0.8 a mapper will be able to do 1.3 bar of boost so again how will it not make more power?

Also a 3 port solenoid may be am idea and maybe a fuel pressure reg as I'm not sure what flow the wrxs injectors can produce but a trusted tuner or mapper should be able to help, in my opinion a turbo is not needed at this stage.

Dan-

Thanks for the help guys!! tbf 300 is abit of a dream but he would be happy with 270-280

on your note with warranty it runs out next month so all is good i went outside and had alook under the car and its got as you say, decat 2nd pipe, unsure on the turbo model it doesnt look as big as my vf35 but cant see a model on it :/ so not sure what boost they can safely run at, i do think he likes the idea of full decat he's getting old now :P, would cutting out the middle box be of any benefit?

Thanks

Gigsy

Sorry fella but...

1) stock boost is ~1 bar
2) PPP boost is ~1.2 bar
3) stock turbo maxes out at around 280bhp no matter what you do to the exhaust and intake
4) uprated fuel pump was part of the newage STI PPP not WRX
5) 2.5 injectors are good for 300+ bhp
6) 3 port boost control solenoid won't allow you to make more boost, it just allows you to control it better

...so, bottom line is, it's the turbo that is the limiting factor thus, if you want more than 300bhp, you need to change the turbo.

Gigsy

It's already got 265 with the PPP... to get to 270-280 you just need to map it. However, your looking at £500-600 for an EcuTek map and around £350 for open source. Thus, IMHO, rather than spending that much for 5-15bhp, you might as well spend a bit more, upgrade the turbo and and make 320ish BHP.


As mentioned above, unless you change the turbo, you won't gain any extra benefit by decatting.

Stock turbo on the hatch is still a TD04L, I believ. VF34 is the turbo used on the STI.

Gigsy

Right, did a little more digging for you...

WRX-S is ~255bhp not 265 as I'd previously stated which to me sounds like it doesn't have any of the cats removed (which makes sense as the current WRX STI 320R is just a remap, no mods to exhaust etc).

So, in that respect, a decat + remap should push you up to 270-280bhp so a gain of 15-25bhp but still, it's quite an outlay for that gain which still makes it better VFM to swap the turbo and shoot for 320bhp (IMHO).

At the end of the day, by the time you shell out for a decat exhaust you've spent the same if not more cash than you would by just swapping the turbo and you'd still be limited to the stock turbo's upper limit of 280bhp.

chrisUK300

iTrader: (10)

It's a VF48 Turbo on the Hatch STIs not a VF34.

Gigsy

Fair enough, just re-read that he was talking about a VF35 anyway. Either, way, none of them are fitted to the WRX which was may main point

chrisUK300

iTrader: (10)

I'm having a pedantic day :-)

Dan-

Thanks for all the help guys , just another question non power question how do we go about getting the Subaru burble out of the 2.5 engine, I've never heard 1 that sounds anything like my 2.0

rob84

iTrader: (5)

A wrx-s will need more than previous models to extract bigger power that 280

Intake manifold is different as is the throttle body
Turbo needs changed. Intercooler needs changed

stevie1982

iTrader: (16)

I stand corrected, you learn something new everyday I didn't realise they increased the boost pressure on the Ppp kit assumed it was the sports cat and fuel pump that helped to increase the power.

Mental note to self, cheers gigsy

To the OP, I would contact a few tuners / mappers and tell them the budget and future plans for the car and see what they can offer you. My personal choice is David at API as I said earlier will offer no fuss no commitment advice and in some cases has used parts at good prices if you want to stretch the budget.

Best of luck with it

stevie1982

iTrader: (16)

Full Decat or a new back box, have a Hayward and Scott on my hatch sti and it's got a growl to it on the throttle but nice and quiet around town

Gigsy

Seconded... H&S backbox and possibly de-resonated centre section (if there is one for the hatch)

Dan-

Cheers for the pointers! What about a straight pipe instead of the middle box?

Gigsy

That's what a de-resonated pipe is

Dan-

Ohh :P haha thanks

Gigsy

No worries