I am seeking a little help if you could please?
I have a WRX 04 - I want to upgrade the exhaust system as the car was standard when purchased, I have put a Nurspec rear box on and it sounds great - but I want power as being standard the power is pants, after coming from 300+ bhp classics.
If I put the full system on, I understand that the engine light will come on? Will this damage the car until I can afford a remap?
Also I have put a HKS induction kit on and sounds awsome but the Turbo smart dump valve sounds pants - any ideas on what dump valve sounds the best and provides the best results?
I thank you for any help you can provide and any info on quick upgrades to improve performance prior to remap.
Chris

 

not like the turbo smart dv then mate

 

If you are on a tight budget take the dump valve off and sell it, fit the standard recirc one back on. Remove up-pipe which has a cat fitted and replace with standard up-pipe from classic or newage STI without cat fitted.
Replace catted downpipe with something like a PPP sports cat downpipe and PPP centre section as you also have a cat in the centre section, these are available pretty cheap. You could also remove the resonated centre section and put in a sraight through pipe. Take your induction kit off and sell it and replace with standard air box and K&N panel filter. Option of an STI8 TMIC for a bit of peace of mind, fit some NGK PFR7B plugs then a remap as soon as possible
.
You could do all this for under £1000 if you do the work yourself and will acheive around 285BHP and similar torques. If you want more then change the turbo and injectors as well.

If you fit the ppp sports cat and remove the two other cats you will have removed a lot of exhaust restriction and will remain MOT friendly. This sportscat has to be modded slightly to fit the TD04 but it takes 5 mins and is very easy.



The WRX has an EGT probe in the Up-Pipe which is essentially a cat on fire probe. When you replace the uppipe with a cat free one you no longer need this sensor. When removed it throws a cel. To eliminate this you fit at 2.2K ohm resistor across the EGT probe plug pins to simulate a standard temp from the sensor.

Hope this helps

 

hi mate what needs to be modded?

 

wow

arch

that was some advise
ill look at some of that myself

 

hi i have a 2004 wrx with ppp, and wanting to sell the whole exhaust system as ordered full turbo back decat today. numbers 07595 255061.

cheers

 

Awsome advice from Arch, brilliant. I'm about to do similar to my 05 wagon, but only have the PPP backbox and a tornado centre section pipe, K&N panel filter. The re-map estimate is 270-275 bhp. Removing up and down pipes sounds complex, how much of the additional 10 bhp is the exhaust and how much the plugs (so is it worth changing the plugs, in other words ?

 

The plugs on their own prob wont buy you any power the 7B's just run cooler.
The up-pipe is a pretty big restriction and well worth replacing but it is a bit of a pain to change but the results are well worth it.

 

Right, what about the MOT emissions. If I'm taking out the centre pipe (which i think has a cat in it and the downpipe am I not removing too many cats to get through an emissions test ?

 

Right this MOT thing
I only have the pro-drive sports cat fitted all others removed and passed MOT no problem

 

Fitted my PPP backbox and resonator section this weekend and it sounds and feels great. Having achieved some success (first time under a car on ramps for 20 years I think) I'm now feeling like attacking the PPP sports cat downpipe and PPP centre section and the up pipe. I haven't got these so need to find them, secondly any advice on how to fit them ?