jameswrx

iTrader: (4)

Is there a nice easy way of getting a bit more go out of a 2003 blob eye WRX?

I see you can buy centre section de-cats, are these any good?

Anyone got some personal experience of stage 1'ish mods on one?

Am I right in thinking the power is a measly 225 bhp?

Would be interested to see it around 280bhp.. if it's relatively fuss free?

Any comments appreciated.

Henrik

iTrader: (5)

Here's my recipe, but others may disagree (oh, and i'm just a hobbyist and not a qualified mechanic etc etc):

* decat up-pipe
* sports cat down pipe (e.g. a used STI PPP down pipe)
* decat centre cat
* some 2.5" centre section (the part that hasn't got the cat in it (just before the back box)
* some 2.5" back box
* STI panel filter
* walbro 255l/h fuel pump
* Remap

That lot should see you at above 280 quite easily, and shouldn't set you back too much money (my guesstimate would be around 1100-1200 pounds (buying everything new apart from the sports cat) if you don't mind fitting the bits yourself (imo, the only hard part would be the up-pipe, which is a pain in the ****).

andythejock01wrx

Henrik has it right.

Mind yer brake pads and Whitleine ARB though.

funkyspider

as above. WRX with 280... Done

You could replace the headers (exhaust manifold in english) with some standard ones which have been ported but plan that when doing the up/down pipe if you are going to do it. A Snet member called Harvey is well known for his ported headers. Might as well wrap the decat uppipe before fitting to try keep the heat down in cyl 3. I used a K&N or Green panel filter rather than STi one simply because it wont need changing as a service item.

There is no need to buy exhaust bits new, make sure they are stainless steel and not bent and second hand is just as good.

If going for a prodrive PPP sports cat downpipe go for the later model with the heat sheilding built inside the metal fat bit in the middle. Earlier ones had an external heat jacket. Newer ones are likely to perform better as cats do degrade over time, especially on cars with a tendancy to over fuel. My MY01 WRX passed MOT no problems with just a sports cat downpipe which I bought second hand (but very shiny and virtually new thanks to someone crashing their STi) off ebay.

Henrik

iTrader: (5)

This is true I've only got one brand new piece, my resonated centre section and it looks completely out of place underneath the car. I only bought it new because I could not find a resonated section after months of scouring the for sale section and ebay (there's lots of unresonated ones, but no resonated ones). I guess I'm the only one going for reduced noise


As a side note, if you want to go past 280-290 on a UK WRX, it's going to cost you an arm and two legs (and maybe a kidney as well), so leave it at 280 is my advice

I don't want to put ideas into your head, obviously (), but additional parts that would need changing soon after are:
* turbo (around 250-300 for a used one in good nick (td05 or a vf of some sort)
* injectors (sti pinkies new for 250 or used from 150 upwards. Absolute pig to change)
* intercooler (sti top mount ~ 200 quid)


Hmm, now that I'm looking at it, it doesn't seem too expensive :-) 1800-1900 for a 330-340bhp car

funkyspider

Or for slightly more power whilst keeping a kidney you could look at a TD04 Hybrid turbo, which has the early spoolup, but stronger pull. There was one fitted recently to a wrx with an excellent write up thread by andy. That is personally where I would be heading to get more power - having driven a TD05 I love the kick in the back, but don't like the lack of lower down power as I tend to drive lower down in the rev range most of the time.

https://www.scoobynet.com/scoobynet-...ow-fitted.html

The rookie

iTrader: (1)

As has been said, 280 is reasonably about the limit on the stock turbo, you can get away with keeping the stock centre exhaust as well (to save a little money) if you like it a little less in your face.

Simon

Henrik

iTrader: (5)

How much is the standard centre section good for?

andythejock01wrx

Thanks for that Funky.

Got any pics of your 01 WRX BTW ?

regards,

AndytJ

jameswrx

iTrader: (4)

Thanks for the help

Would the car still pass an MOT with 1 cat? If so, why do they have three of the beggers?!

funkyspider

My car passed MOT with just the Prodrive sports cat downpipe as fitted with the STi PPP pack. After five mins to warm it up it was well within spec.

STi only has 2, missing out the up-pipe cat so no idea why they fit that one to the WRX anyway. I think it may be something to do with the regulations manufacturers have to stick to for emissions being at a certain level when started from cold. A cat wont work properly until up to temp, I should imagine a single cat would not be efficient enough from startup - hence mine needing warming up before it passed.