sticky1985

Hi there, got a 2004 wrx, shes done 50000 miles and is my pride and joy! im looking to carry out some moderate tuning, nothing crazy as its just the wrx lump, i need advice on what items and kit i need before a remap.
car is standard apart from a k&n induction kit, and Afterburner Vortex back box, any ideas would be great as id like to achieve good Safe power gains, improved torque, and drivability.


much love!

jura11

iTrader: (7)

Hi there i would say,3 port boost solenoid,ditch K&N induction kit replace with OE Airbox,decated exhaust including UP PIPE and you will see around 270-280bhp with good remap,here is few good mappers like OS(open source £230-£350) or EcuTek(£550 excluding VAT)

Jura

MDS_WRX

iTrader: (1)

Do you think this is really required? I'm going to be going to be doing the same as the OP in the next month or so (have all the bits ready etc) but I hadn't planned on getting this.

OP - I'd say prerry much the same as Jura, get a full decat from the turbo back and then a remap to get to a safe 270-280. Depending on what you want to do, you could do it on a budget from around £600 or you could go all out and easily spend £1500 on a top end system and map.

sticky1985

hey Jura, ive looked at decat as it would sound amazing, but what about mot's and that, wouldnt it fail?

Gigsy

Ditch the induction kit and fit a panel filter to a stock air box (good for 350+bhp and less susceptible to sucking in hot air).

Then fit a silicon Y pipe from the turbo to the intercooler, decat the center pipe (3rd cat) and get it mapped (basically what Subaru do on the PPP). Should give you 260 - 280bhp without stressing the engine. An uprated fuel pump is a worthwhile safety measure.

You can eek a bit more power by de-cating or fitting a sports cat down-pipe / up-pipe but realistically, you hit a wall at around 300bhp with the stock turbo and injectors so unless you plan on fitting a bigger turbo, it's not really worth the expense.

jura11

iTrader: (7)

Hi there you can may go via Sport Cat route,which is less restrictive like Standard Cat,Cobra Exhaust selling this or Japspeed selling this,just don't buy with flexi flange..


Jura

MDS_WRX

iTrader: (1)

Yes, a full decat would fail. You could go for a sports cat downpipe which will allow it to pass (but budget another £150-£200) for one of these. Alternatively, you would have to swap the cats back in before each MOT, or ask around to see if anyone close by can help you out

Gigsy

2 port works fine in most cases. 3 port just gives you better boost control.

MDS_WRX

iTrader: (1)

OK cheers

jura11

iTrader: (7)

Hi there i would say yes,but don't fit 3-port boost solenoid,leave this part on your mapper,because if you are fit 3 port solenoid you will need run off the boost until car is properly mapped..
3 port boost solenoid they hold boost far better than the standard OEM 2 ports..


Jura

sticky1985

excellent advice from all, defo sounds like i need to remove that induction kit and go back to the standard box with uprated panel filter, and for the price a better fuel pump is a no brainer. Vortex decat center section and down pipe me thinks! lol, would sound ace!

monkfish2

Hi mate, I have a 2005 wrx and currently running at 285/297. Removed all cats and added a sportscat, uprated fuel pump, changed panel filter. Andy Forrest remap. If I would have changed anything before remapping, maybe a td04 hybrid, based on not being too keen on lag. Still not sure if the extra 15 bhp is worth the extra £600 though. If you want more gains than this, the only sensible thing is buy an sti and mod this.

daz1968

iTrader: (13)

When I had my wrx I just fitted the ppp kit including the ecu. In my opinion to go to the added expense of changing up and downpipes and custom remap would be better spent if a larger turbo is fitted first, a vf28, vf30 or vf35 can be picked up cheaply along with a set of sti injectors

EngineMapper @ Group B Motorsport

Fuel pump heavily recommended, panel filter in OE airbox, decat up and down pipe and remap and you will have a fantastically driveable car.

The original map is really held back and a remap encourages the turbo to reach peak boost faster, widens the powerband and takes the car up to a much higher peak power.

Last WRX I did netted 284bhp & 297lb/ft torque. Worth it IMO over the standard lack-luster performance.

Graham

Paul Hutch

Sell the WRX it's the peasents model and get an STI be a man and mod that haha

dynamix

iTrader: (3)

a 3 port isnt really needed on a 2004 wrx - they make boost just fine on the 2 port

If you are still on the original turbo then the fuel pump should be fine.

If you are worried about passing the mot then just a centre decat and good choice of system should give you around 270bhp and similar torque whilst still remaining mot friendly.

This is one I mapped up at scoobyclinic recently that still had uppipe and downpipe cats in place:

EngineMapper @ Group B Motorsport

Good results on just a centre dacat! Personally I like to map them with a much more agressive boost pattern, you can bring the power delivery in about 1000rpm lower and still reach the same peak bhp with a much more driveable car. Here's my dyno example, (just to join in Duncan!).

This is wheel bhp and torque at 1.2 bar 2005 WRX, the customers requirement was more power, but concentrating on a much wider powerband. When put on a Dyno Dynamics it made 271bhp and 285 lb/ft at the flywheel.



You can see between 3000-4000rpm the turbo is already at target boost pressure and producing max torque around 3600 and retains a very flat torque delivery until 5000rpm.

This is my preferred type of road car, with good useable power between 3000-6000rpm.

Graham

s70rjw

iTrader: (2)

The decat, fuel pump, air filter, remap will bring the car alive and will be a terrific road car. If you go for a VF35, decatted up pipe and STI pinks, you will get an easy reliable 300+ bhp. An extra £400 should cover turbo, injectors and decatted up pipe if you use previously enjoyed parts from the for sale section.

dynamix

iTrader: (3)

graham - that is a road dyno sheet yeah ?

EngineMapper @ Group B Motorsport

Yes that's a road plotted dyno graph with my datalogging tool.

Graham

dynamix

iTrader: (3)

in which case so you will appreciate that the torque and boost profile on the road is much more agressive that that shown on the DD dyno plot above with full boost way before 3000rpm.

EngineMapper @ Group B Motorsport

Duncan, my point merely was that they can be tuned to widen the powerband considerably over a standard map and come quite alive!

Graham

daz1968

iTrader: (13)

Dynamix mapped my jdm sti and I would recommend his services to anyone, was a very good experience tbh, but if you can get 270bhp plus with std downpipe in place then probably not worth the expense and hassle of removing the cats. I still have std downpipe on my car currently, but may consider changing it in the future if it will give a worthwhile gain after a map tweak.