hairdye

Hi
i bought a de cat pipe for my classic sti yesterday and was told i might need to upgrade my fuel pump or else it may run lean. Well was going to fit it today but then i was told i didnt need a fuel pump but would need a re map, then i was told by another it would be fine without doing anything to it and just fit the pipe.Please can someone offer me advice on what to do as i want to fit this pipe on but dont want to blow the engine.
cheers
wayne

myblackwrx

iTrader: (1)

I've had one fitted to my early WRX and had it r/r and it was fine but with an STI it may be a different matter.

scoobyDAZZA

you'll be ok with just the decat

IF you fit an uprated fuel pump (walboro) then you'll definitly need a remap (apexi,link,simtex etc)


still worth saving for 1 anyway , the decat mod will benefit from it

yours is a 96 i see so you'll need an aftermarket ecu mapped, as above ,
simtek seems the 1 at the moment , approx 950 + vat fitted and mapped or an extra 150 -250 with anti lag and launch control

scoobyjay7

Unless you have 350 bhp you will not need a fuel pump.
It is advisable to get it remapped but not neceseray.
I think also (not sure) but if you keep your boost below 1.0 bar you will be able to drive it for ever with no probs(please check first)

aidyc

i am looking for a decat downpipe too but unsure what to buy, what make did you buy and how much was it if you dont mind me asking

hairdye

Cheers for the replies
so it should be ok to fit, i may have some more questions later as im also fitting a boost gauge tomorrow.
cheers

hairdye

Hi
its HKS and i bought it for £120 nearly new off a fellow scoobier from here.
cheers
wayne

lightwave693

you dont need a remap with a fuel pump, fuel pump just pumps fuel, the fuel pressure reg sorts out any excess fuel and shoves it back in the tank. walbros might over power the standard fuel pressure regulator, so fitting an after market one doesnt need a remap as long as its set to standard pressure.. decat downpipe wont NEED a remap but would benefit from one.with the decat the boost comes up a couple of RPM earlier than normal which might fool ur current map so it doesnt squirt enough fuel for the increased air at the lower rpm.

depending on the year of ur car a fuel pump replacement/upgrade is recommended regardless of power goals.


Rich

N602 WRX

lightwave
Ive also heard of the walbro overpowering the standard reg.

when fitting the walbro and a aftermarket reg what do you do about the pressure? set it to standard? or do you up it? if so what to?

sorry for the hyjack wayne!
wez

scooby-wrx

hairdye, I wouldn't worry. A de-cat just bolts straight on and will be fine. I have a 96 Version 3 STI and I fitted a 3.5" HKS de-cat without any other changes and it runs perfectly. It will sound great! Post some pics once its on.

Cheers...