Im currently upgrading a few bits on my 04 wrx
walbro pump
fmic
induction kit
decat uppipe

it currently has a afterburner vortex backbox and a afterburner 2 and a half inch centre section.

im getting a decat downpipe, the question is do i get a 2 and a half inch or get a 3inch and replace the centre with a 3inch?

any advice much appreciated

 

3" all the way matey,thats what i have on my wrx,you should add an sti turbo + injectors to your list should see you with about 330 bhp thats what im doing,also dont forget a 3 port boost solenoid

 

thank you, and yeah the vf34 is it? and pink 550 are going on the list, but will have to wait, the remap is more important at the mo and will clear my bank ... forgot to mention i have got a perrin 3 port ready to go on

 

surely its better to get it mapped when all mods are ready-saves mapping it twice then

 

i would but.... the car has the ppp pack but since then it has had the back box and centre changed plus an induction kit (both put on by previous owner) theres nothing in my folder to suggest its been remapped since, plus the 1st map (if it hasnt been mapped) will include the license fee so at least the 2nd map will be a fair bit cheaper

 

Ditch the FMIC bud, use a STi top mount. Unless you are going over the 400 mark.

in my opinion the 2.5" is adequate up to about 350BHP, so if you want to save a bit of cash and arent looking at over 350 then.....

hope that helps.

 

I have an 05 wrx. I started with 2.5 straight through system but just had to upgrade to 3 inch as I wanted c.350bhp....the spool is a million times better with the bigger bore system! I second the sti top mount....I went sti top mount instead of fmic because you dont see the benefits till over 400bhp. You get lower intake temps but then its laggy compared to the tmic due to the length of pipe work (that is until you want more than 400bhp and then you NEED the lower temps).

Hope that helps

 

3" all the way thru
Top Sti Intercooler

 

Hi there

Really depends on your power target,but 2.5" should be OK for 350bhp without the problem,we are run 350bhp with 2.5" exhaust and 2.5" is not restricted up to 400bhp(above that bhp few people still running 2.5").With 3" you can loose torque.

If its budget VF34 will be mine choice,if not VF35 should be good choice,but still I would prefer VF34.

STi Pink injectors will be needed and as above would fit everything in one go before mapping

Jura