Hi everyone i have a 2005 uk wrx and have recently fitted a prodrive back box, and i was told a n sti middle pipe. would this mean i have two cats left, i basically want to decat the downpipe but want to pass mots with no worries . any ideas? sports cat downpipe. will be remapping in summer. cheers

 

Hi there best bet will be for passing MOT Sport cat(Cobra Exhaust have for good money) and decated center pipe and as well Up pipe you will need...
I'm guessing you have fitted TD04 which will be/or should be OK with decated exhaust,and you will run without problem few month to remap..



Jura

 

Hi there thanks for reply, it still has standard turbo,just looked at a diagram on here and ive realised that i still have all cats so am i right in thinking that i get rid of centre cat/sports cat on downpipe and decat uppipe and that should do it tuning and mot wise? obviously with other mods, i.e panel filter etc?

 

same car as yours, I'm running a sports cat downpipe, got rid of all other cats and pass mot fine

 

Hi there here is Exhaust diagram for WRX/STi....

If you fit just Sport Cat(and other bits will be decated like center pipe and up pipe)you will pas MOT without problem
About the recommendation for remap,you will need uprated panel filter like is it K&N or Green Cotton,your fuel pump will be OK,3-port boost solenoid is must(this will fit mapper,don't fit this yourself,because you will need run off the boost until remap)


Jura

 

Excellent help guys i now understand where cats go many thanks! what do u reckon 270 ish at the flywheel?

 

Yes matey 270-280bhp is probably realistic,300bhp is possible too..


Jura

 

Had my WRX mapped by JGM yesterday with:
- Modified STI up pipe
- Prodrive sports cat downpipe
- Prodrive decat centre section
- Catback stainless 2.5" system.
- Green panel filter
- APEXI 3 port boost solenoid
- Walbro fuel pump

Made 272bhp and just over 290 ft lb at the flywheel.
Considering the bhp exceeds standard STI power figures I'm happy with that
You might get a bit more if you go for bigger pipework?
I wouldn't think you'll see 300 unless you fit a VF34 or VF35 and bigger injectors, and then STI intercooler etc.

 

What a fab little thread.

Helps a 'newb' like me very much!

Subscribed for future reference

 

02 wrx

full decat sti up pipe walbro 255 drift panel filter3 port boost solenoid

made 280 bhp 290 ftb on scoobyclinics rollers mapped by duncan aka race dynamix

 

I have a second cat removal pipe. if your after one.

Ran it on my 06wrx and passed MOT no problem.

PM if your interested.

Is just gathering dust.

 

I think the hawkeye setup is a bit different from the blobeye though IIRC, I think its slightly longer on hawk....

 

so the best way to be legal for emissions is to remove uppipe cat and mid pipe cat and sportcat the downpipe? Sorry just wanna make sure. Any probs with dash lights with this setup? Thanks again.

 

Blx sorry my mistake u are correct it is...

Must of drifted off for a bit there...

 

Hi there i've run full decated exhaust without CEL...
If you are fit Sport Cat and decated center pipe,up pipe you will pas MOT...



Jura

 

perfect thanks guys will post my results.

 

Those are VERY good figures on a TD04 mate, but then I guess you're full decat - so considering there's only 8bhp in it, the sports cat can't be all that bad eh?
We found yesterday that I had a leak in my up pipe gasket, was screaming on full boost - 'orrible noise!

Fitted a new gasket yesterday - I reckon it would probably make a little more now.
280 is still a good figure - did they open the bonnet when it was on the rollers? Always worth a few more bhp

 

Replace the WRX up pipe with an STI up pipe - they have no cats and are cheap as chips - you'll probably pick one up for around £40-50.
Then a sports cat and decat centre section.
I was lucky and picked up both of those for £100 on here, you never know your luck.
You should also change your standard air filter to a quality cotton panel like Green or K&N.

And BTW - don't just do all this and drive the car.
When you remove the centre cat you'll get a CEL light (engine warning).
You should have the car re-mapped once the mods are done - if you have to drive it drive it off boost until the mapper's done their work.
HTH

 

Following the gasket replacement and a JGM map tweak, mine made 281bhp and 290 lb ft at Surrey Rolling Road mate so all good these TD04's

 

Be aware the STi up-pipe has no EGT sensor boss (which the WRX has) so you will have to map out the EGT sensor CEL or fit a resistor fix

Shaun

PS the exhaust diagram above is for the WRX and not the STi

 

Looking at doing this to my bugeye as I have a mapped chip waiting, I just have a couple of questions:

1. what is the 3 port boost solenoid for? Does it make a difference to the map? It's only that the guy I got the ECU off didn't mention this as 1 of his mods.

2. If I get http://cgi.ebay.co.uk/Subaru-Impreza...item1e62fe5992 or the Ninja one do I need to remove part 1 (midpipe) as this looks long enough to bypass that also?

I'm only asking as I want to get the parts together rather than find I'm missing something half way through changing the downpipe!

TIA

Ian

 

you have a 2 port boost valve as standard So a 3 port is an upgrade, it will need to be mapped in though.

 

quite often a decat downpipe includes the mid section So you don't need to worry about that

 

Just curious what you mean by a "mapped chip".......if it's been custom mapped for the other car (I guess it has because he ran a 3 port) then it likely won't work 100% on your car because all cars run differently.....you will be better getting your own ECU mapped individually for your car.

Shaun