chip01

Which one is the best to go for on my STI 5. I am thinking of having quite a few things done at once.

HKS downpipe
5 Zigen Border 304 max cat back
Resinator pipe removed with straight through pipe
Graham Goode K&N induction kit for STI 5 (to help MAF problem)

APEXi S-AVCR or Pwr FC Boost solenoid kit (or some other boost increase kit)
FSE Fuel Pressure Regulator
Uprated Fuel pump 260 l/hr
HKS Iridium Spark Plugs

What do you guys think would you change anything and what is the best ECU which is my main point

Keigo

Chip - YHM in a bit

harvey

iTrader: (48)

Before you spend any money sit down and work out what you actually want to achieve and what budget you have over what time period.
That starting point is usually an FSE pressure regulator and Walbro 255 lph pump. These are available for £195 including postage up to the end of this month info@asperformance.com
Next on the list would be a good 3" exhaust system. I can recommend the Roger Clark Motorsport 3" open neck or a similar system from Hayward & Scott. The workmanship on the RCMS item is absolutely first class. For an exhaust you could use the Revolution system which is efficient and cost effective and not too loud or the louder centre pipe and backbox from Scoobymania.
Also consider getting your headers ported. Done properly this will give better spool and flow for not a lot of money.
With a K+N panel filter and the standard air box you will already have a fair power hike and if that is as far as you are going the fuel pump and pressure regulator are not required.
Personally I would not use HKS plugs again and NGK PFR 7B are quite adequate for your needs. I have had an insulator break on the HKS and this cost me a cylinder head. Others have had the insulators break too.
You can get a GBE boost valve for a slight increase in boost but you need a boost guage to know what you are doing and your AFR should be checked on a wide band Lambda at full throttle afterwards.
Now at this point you will have got reasonable power gains for not a lot of money and to go beyond this point will take much more expenditure.

You can now consider a set of tubular headers, induction kit with cold air box and feed and an ECU. Depending on your turbo the Gruppe S headers show good gains along with an up-pipe and these are 400$ from the US. You will save a fair bit making your own induction kit around a large K+N filter, not necessarily a cone, with an appropriate cold air box.
I assume you have 440 injectors and these will be maxed out around 350 bhp. Depending on your turbo which may be a VF28 you will be reaching the limit of its ability on the 440s.
ECUs : The Apexi Power FC with hand held commander is relatively cheap from Greenline in Japan. This system relies on the MAF sensor. An alternative would be the Link system which is more expensive but does away with the MAF.
Hope this is helpful.

Bob Rawle

Its worth pointing out that HKS plugs are actually DENSO ... good plugs for mildly modified cars but not for high boost applications.

bob