Ok so the exhaust and tune have been done....need more power

[coyote]

I knew I'd regret posting in this thread.

I said I "think" the stock injectors might be 560cc. They appear to scale to lower than that, but 560cc is a common size used in other similar Subaru engines, so as cpitts said, it would make sense that they "may" just have used the same ones. If someone wants to pay to have one flow tested, I'll quite happily provide a more definitive answer.

As Goxer said, you simply can't do a good job of working out on paper what an injector will make in an engine unless you know far more about that engine than any of us obviously do. I can tell you that a turbo Subaru engine will produce about 100kw per 200cc of injectors, but I'd also want a 25% fudge factor depending on a whole bunch of things and another 25% based on what fuel is used.

Practical evidence is always preferable to back of the envelope calculations based on internet whispers. I know what my IDCs are and based on that I'll tell you that anyone who says that an engine the same as mine will make 240kw atw on pump fuel with IDCs under 100% is just plain wrong (or their dyno is). I'm sure you're relaying that info in good faith cpitts, but it just isn't true with standard injectors at standard pressure.

You could increase fuel pressure or do a number of other things, but you will not make 240kw atw on a completely stock fuel system. If anyone is, watch it for a while, because it's about to go bang.

[cpitts]

Coyote, it's excellent that any discussion on this can be had. Don't stress on the feedback, it's all just banter. Any experience you have is superb, sounds like there's a lot more to it than fiddling around the edges.

I've popped a question to someone who should have the answer on injector size, so see what I can find out. The 100kW/200cc number sounds like a reasonable assumption, esp given the fudge factors your talking about.

Actually, on that note I'd be talking about using 98RON petrol as a reference, most likely the worst on the market (Shell Optimax).

[Boxer]

You can get over 170kW ATW from the injectors in a 2l WRX and it uses a smaller turbo and has a lower factory stated peak power figure! I highly doubt FHI will provide a vehicle with higher peak power figure, bigger capacity and bigger turbo without increasing injector size to suit. I'll dig up some CC sizes for injectors and see how these compare.
EDIT: It's worth noting that the 2l WRX STi (factory 208kW) has bigger injectors than those on a standard WRX (factory 165/168kW). Our cars power is closer to that of the STi, so I'd be inclined to think that FHI will simply pick from the STi parts bucket and drop in the bigger injectors (think volume purchase from Denso and lower part count for dealerships). The only adverse affect of bigger injectors (well at this size anyway) is a slight fuel usage increase at idle.

I'm sure you can - no arguments, and I'm sure you'd get more than 170kw @ the wheels in a Lib GT too. But at what IDC?

I mentioned 170kw @ 80-85%

Have far you want to push it is entirely up to the owner/tuner

The rest of that paragraph is assumption (but some may well be true) But does that change the facts of what dyno results have already proven in regards to how much HP the stock injectors in a GT will facilitate??

[Boxer]

most likely the worst on the market (Shell Optimax).

I'd like to challenge that - Vortex 98(ish)

....and coyote - fix the B on your keyboard

[Arith]

....and coyote - fix the B on your keyboard

Yeah! You tell em Goxer!

[Boxer]

Hahaha Jim everyone's a comedian

They say 'fools never differ'

[ultrablue]

injector selection guide
http://www.injector.com/injectorselection.php

[cpitts]

Good site Ultrablue. Based on that a basic 300hp setup (typical of the STi) needs 600cc injectors.
I though the std STi injectors (for a Impreza) were at that ~550cc mark, clearly there's a certain fudge factor there but it sure means that the 220-240kW ATW type boundry on 550cc injectors is clearly at the 100% IDC side of life which is a bad thing. I'm still pending a reply on the modded Lib I know of with 220-230kW ATW. Am pretty sure it didn't require injectors for those numbers.

[PHAT GT]

Hello Mr Coyote long time no hear



Cpits i can tell you with 100% convenience all you'll get from the factory injectors fitted to a 2.5L Turbo Liberty on shell 98 with a A/R reading of 11.9 and 280L/h Sard pump with a idle pressure (800 odd rpm) of 34psi at 100% IDC is 217KW@wheels

*this was done to just to see how far they would go BUT i HIGHLY DONT recommend anyone try this (before anyone asks there where other mods done to the car to get this KW from the car

here are a few pics of the factory injector and its part number i took as i dont think many people have seen one out of the car as yet





Peter

[SillySora]

This is awesome . Does anyone know how long it takes to install injectors at all.

[Arith]

Who the heck is Peter?

[PHAT GT]

This is awesome . Does anyone know how long it takes to install injectors at all.

at least 2 hours given you have a good tool set and Inj plugs dont need to be changed as there barred under a few parts and the rails have fixed lines so its quite a mission even with experienced hands

Robben

[Boxer]

Well there you go - the proof in the pudding. Thanks Phat, Peter, Robben (Batman??)

Out of interest - any ideas on max HP with a safe IDC? (say85-90%)?

Did the Sard make a huge diff?

[PHAT GT]

Well there you go - the proof in the pudding. Thanks Phat, Peter, Robben (Batman??)

Out of interest - any ideas on max HP with a safe IDC? (say85-90%)?

Did the Sard make a huge diff?

i think without the the pump or a smaller pump i dont think it would have even gotten that number as the bar rate (3.5kg/cm squared. where did they hide that that button with the little 2 on it ) of this pump is almost twice that of the factory one and at least 1/3 heigher than the waljunk pump

*Just a note there is a pump (made in Japan that is a direct replacement for the Libertys and is the only one on the market that clips in) (YES CLIPS IN unlike other subies) and you wont hear a thing unlike when you have to butcher a waljunk in there

David

[cpitts]

<snip>
Cpits i can tell you with 100% convenience all you'll get from the factory injectors fitted to a 2.5L Turbo Liberty on shell 98 with a A/R reading of 11.9 and 280L/h Sard pump with a idle pressure (800 odd rpm) of 34psi at 100% IDC is 217KW@wheels

Appreciate the info. Also, great to have the part # for ref!!

Was this figure taken on a Dyno dynamics dyno? If so, that'd make good sense as it compares directly with the numbers I've been advised on a dyno that reads in the vacinity of 15-20kW higher than DD dynos (as mentioned in earlier posts).