What size injectors will I need?
 

I've just fitted a Walbro 255 fuel pump & asked the question what max boost will my TD05 push out. It seems 1.4 bar is a safe bet. I have a remappable chip at the minute running 16.5psi.
What size injectors will I need if I want to run 20psi?
Am I missing anything like will I run into other problems like MAF problems?

Cheers :thumb:

what year is it and how do you intend having it mapped?

Assuming it is a classic here are some rough figures for you.
380 cc injectors will support 280 bhp
440................................ 325 bhp
550.................................400 bhp
740.................................540 bhp.
Now before anybody tells you they can get a lot more, these are figures, in practice at modest fuel pressure and before the injectors are maxed out.

Sorry for not giving you a little more info. Its a 1995 WRX. I was told when I bought the chip that it could be remapped at a later date. I'm just fishing for info on the right way to go about increasing the boost a bit more, what I need to do or not do. Cheers.

sorry no problem.. just a few people have been fitting bigger injectors and turning the boost up on the standard ecu and wondering why it runs bad.

Simon

Am I on the right track if I bought a set of 550 injectors then got it remapped to run 1.4 bar? Or is there something else I'm missing?

Thanks for all your help :thumb:

If a turbo, ecu, injectors and fuel pump are your only mods you'd be missing out on a good deal of 'free' (mechanically speaking) power.

Your standard fuel pressure regulator is unlikely to last long with that pump.

Full de-cat exh would be a good start

The 95 intercooler is crap really, cost effectively a sti V one and hoses would be a real upgrade for not much outlay. Even better is the sti7 one, but it's a bugger to fit. still very cost effective (personally i wouldn't bother with the V5 intercooler).

an uprated panel filter (never used one myself so don't know how good), however the 95 has a more sturdy maf sensor than some later models so you'd most likely get away with an induction kit without problem. pick carefully though

That's a good start there I'd say. :)

Dave

You will need a 3 bar map sensor on a pre 1996 car, as the standard map sensor peaks at 1.2bar.
You can use a map sensor off a later car but you will have to have the map rescaled to work with it.

I've had an Apexi power intake induction kit for a while now but never fitted it untill other mods were carried out. I also have a Blitz NUR Spec R exhaust fitted & a de-cat downpipe to follow shortly.
Thanks for pointing out about the map sensor, heres my shopping list then...

1. 550 injectors
2. 3bar map sensor
3. Remap

What about uprated fuel pressure regulator?

Thanks for all your help :)