Hi guys,
i am in need of bigger injectors for more power from my engine (gc8 STI), and was thinking of going for some 550s. just wondered because i may possibly be able to get some quite cheaply - what would happen if i put 650s or maybe even bigger in?????
what it cause a problem???

all opinions and knowledge very welcome...

* Fully forged STI engine,
Omega forged pistons,
Manley H Beam forged conrods,
V9 STI Nitrided crank,
Piper cams,
ACL mains and big ends,
V3 STI ported and polished cylinder heads,
Nimonic exhaust valves,
New timing belt and tensioners,
Lightweight flywheel and pulleys.

* TD05 Turbo
* New STI gearbox and diff
* New STI clutch
* Apexi Power FC ECU and handheld Commander - Mapped by Zen Performance
* Apexi AVC-R boost controller
* Tubular manifold
* A/M Exhaust Headers and Up-pipe
* Uprated Fuel pump
* Zero Sports induction kit
* Baileys Dump valve
* FMIC with Hard pipes

 

If you put in some injectors that are way bigger than your needs then you will get irratic idling problems.
If your still wanting to aim for 350bhp as you stated in your other thread then your choice is either some 440's with a fuel pressure regulator, or some 550's, which would give you some flexability if you ever wanted to go past 350bhp

 

No problem if you use bigger injectors as long as its mapped properly.

 

Thanks again guys!

 

Exactly as Max says.
Bigger injectors do not mean more power per se. If you fit bigger injectors you need a remap almost immediately afterwards. Generally it is the turbo that determines the injectors in use. You appear to have a good spec. At present you will have 440 cc yellow injectors and these will max out around 325/330 bhp without an FPR. Your turbo is probably good for somewhere between 330 and 350 bhp if it is a TD05 16G subject to how good and complimentary your mods are so injectors on their own won't neccesarily give much benefit after mapping.
If you have a 16G at present and in view of your spec you could go to a far bigger turbo if you wanted to produce a lot more power and you need to give this consideration because 550cc injectors will take you in the direction of 400 bhp without an FPR and 740cc injectors will see you comfortably into the 400-500 bhp bracket without an FPR.
Can you expand on this bit :