ive got a 04 wrx ppp i have a decat downpipe and system, what i want to know is i have bought a cheapass vf34(£385 new woohoo) and a frontmount intercooler. once these are fitted with remap what kind of power am i looking at reckon this will be quicker than the wifes 56 sti

 

You'd also need a new uprated fuel pump (not sure what size the injectors are on a 04 WRX, but if they were 380s they'd need to go too) and I'd consider getting your headers ported and wrapped. Oh, and -depending on the view of your mapper a 3 port boost solenoid.

£385 for a new VF34????? Is it from Flea bay???

With those mods, your car should be quicker that the wife's STi, but why not just upgrade to an Sti too??

Ns04

 

Maybe 340bhp. But then maybe not.

 

ive got 332/312 on my 03 wrx

td05
decat
fmic
sti injectors and fuel pump

 

More than likely until she ups the ante with a remap
Expect around 300bhp, you will be limited by the injectors on your WRX.

 

new scoob, question, honest one. How do you port headers? They're just tube, unlike some cars with cast exhaust manifolds, there's really not much you can do to tubing...

 

To port headers all u are doing basically is opening the ends that match up againt the heads on the engine, can be done with a dremel.

 

Once you remove your headers you can see a carbon build up on them and all you need to do is open it up a little, as the previous post states you can use a dremel to do this , However the key is not to go to deep as they may crack when there back on the car

 

I see, i had just never heard of porting headers before. I thought he meant maybe porting the heads and it was just a typo. I've built quite a few american v8's and hadn't come across that, but it's probably because i've always replaced the existing cast manifolds with brand new headers. thanks guys.

 

Porting the headers on a twin scroll car is rather more complex, as they are tube, but the end flanges and joins are welded from the inside.

We take them off, weld them on the outside after stripping off all the shielding. Then we remove all the welding on the inside of the pipes and flow out the flanges so that there are no restrictions all the way to the turbo

Then wrap in heatproof material refir and watch the spool up really sharpen.

Quite complex compared to the rather easier old cast iron style but it still carries all the benefits.

David APi