JR04

On an STI6 what is the best things to do next after fuel pump and full decat 3 inch exhaust. What mods do I need to get done for more power and when has it changed enough to need a map.

joz8968

iTrader: (13)

It's worthwhile remapping it now!

You've done the correct thing in replacing the pump with a new Walbro and doing a full decat. You've made the fuelling safe and done the most cost-effective potential 'bhp-gain' mod in going full decat/system...

When you get it mapped, should get up to around 320bhp with the decat added (further bhp is limited by the presence of the v.6 TM - although it may make more...) - but still a healthy 44bhp or so increase over stock.

uk300scoob

iTrader: (24)

try an airfilter locating it in the wing and upgrading the top mount for more power out of the remap

Splitpin

UK300 - changing the air filter at this point would be a positively bad idea given the tendency to change the mass airflow scaling and thus the risk of running a car with a japanese fuel map even leaner. Besides which, no reason to remove the factory airbox until modifying considerably beyond the capabilities of the STi6 turbo and injectors.

JR - are you running your car on V-Power with octane booster, and are you monitoring knock? If not, it'd be worth investigating a remap sooner rather than later to ensure that your car is running safely on UK fuel. As things stand it will be mapped for Japanese flavour sauce.

joz8968

iTrader: (13)

To add to Splitpin's comments, the v.6 (and v.5) STi's run quite aggressive maps and it's advisable geting the car mapped asap from a saftey aspect, more than anything else...

JR04

Thanks for the help.

harvey

iTrader: (48)

Two things that will help you. First as Splitpin suggests, you could run with octane booster which will make your engine safer in the short term before the remap. However if you run octane booster during mapping then you are stuck with that fuel mix for the rest of your car running until you have a further remap.
Some octane boosters are just snake oil so be careful. I know from testing that Nitrous Formula (NF) is effective both in terms of cost and performance. NF improves the resistance to DET or used during mapping it allows for more advanced ignition timing and hence torque.
NF is imported by Roger Clark Motorsport and they can supply you by post or give you the location of your nearest dealer.
Secondly, before remapping, you could fit ported headers and matched uppipe. Even without remapping you will feel the difference with a more willing and responsive car and with mapping you will get the best out of the mods you have already done.
Choice of a competant and interested mapper is important.

P.S. Stick with the O/E air box for now. A different pannel filter MAY add 2 bhp over the Subaru cardboard item but is reusable. RCMS have K+N pannel filters in stock if you want to go to that expense. Not important at present.

JR04

I will order some nf this morning. How muchare ported headers and how big a job to fit.

petedotuk

Send Harvey a PM who sells & fits them, That wasnt a sales pitch btw, he speaks the truth.

joz8968

iTrader: (13)

JR04, see harvey's post #16 (bottom). It tells you all you need to know about said job:-

https://www.scoobynet.com/general-te...ipe-decat.html