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

[cpitts]

<snip>
Without me having to go searching does anyone know what injectors the 2.5's run?

I'm yet to hear of anyone needing to upgrade injectors with power levels up to 240kW ATW. I'm basing this on those that have modded with reputable tuning houses that keep an eye on IDC, fuel temps and fuel quality contingency. About the only thing you may consider (which I'm looking into) is a parallel rail setup to ensure even and consisten pressure to all injectors under max load. But even that seems to be less of an issue on these 2.5l blocks. Maybe FHI figured out their end of rail pressure issues, etc. . . . . . . or maybe not....

[coyote]

Unless it is the highest reading dyno on the planet, any GT Liberty with standard injectors making 240kw atw is reading waaaaay over 100% IDC or has much higher fuel pressure than standard (or both).

Subaru worked out how to have individual fuel trims for each cylinder by setting up a table of pulse width compensations. If you go with parallel rails, you've have to adjust that and I reckon you'd REALLY want to know what you are doing and how those values are used.

As long as your pump can maintain pressure and flow, parallel rails are not necessary in the newer cars ... and an absolute waste with standard injectors.

[cpitts]

The AVO dyno does tend to read high by comparison to others (maybe +10-15kW ATW). IDC would be measured with a Walbro/Bosch replacement in-tank fuel pump so you'd probabaly steel back 10% IDC there as well.

And as for tuner skills. That's why I use people that do this thing for a living, not me. They've tuned all this stuff before to much higher numbers than my car will ever reach (and most on this forum as well) so the otherwise 'basic' mods we're talking about here are pretty entry level by comparison.

The arguments for/against parallel rails are always hotly contested. Mind you, I've had the same arguments about air filters, silicon pipework, etc. So to each their own.

scary was after some opinions, and that's what he's got. Everything from part numbers to 'take it to Vendor X'. It's up to him to sort the wheat from the chaff now.

[scary]

soo back to the question......does anone know what injectors the 2.5 runs??

[coyote]

soo back to the question......does anone know what injectors the 2.5 runs??

Top feed Densos.

I "think" they are 560cc @ 43.5psi.

[WhiteGTB]

soo back to the question......does anone know what injectors the 2.5 runs??

Top feed Densos.

I "think" they are 560cc @ 43.5psi.

Tony, you know wayyyyy too much, you are one of the few that knows their shit but keeps very discreet about it

[Resonate]

Coyote is a sleeper.

[cpitts]

soo back to the question......does anone know what injectors the 2.5 runs??

Top feed Densos.

I "think" they are 560cc @ 43.5psi.

If we know the cc's of fuel that can be delivered, then given an AFR of ~12 (typical target for a tuned EJ-T) what's the peak power that can be derived with these injectors? I don't know of the formula, but surely there is one!

[Boxer]

Craig, way too complex to nut out - rpm vs fuel rate for starters and then you'll need the capacity of each cylinder and take into account the volumetric efficiency, boost, amount of burn blah blah

Far simpler to know from experience what the injectors max out at whilst monitoring AFR on a dyno and then I'd only go to a max of 90% duty cycle for some headroom.

I think most people see 80-85% at 170kw so I dont think you'll see 240kw on stock fuel delivery

[Sentinel]

Some great discussion in this thread - might keep a watch on this one.

[SillySora]

I'm upgrading mine to the 750 sard injectors as I'm also getting the avo silcone pipe and 450 turbo I will let you know should be going on next week ohh and equal length headers

[Sentinel]

I'm upgrading mine to the 750 sard injectors as I'm also getting the avo silcone pipe and 450 turbo I will let you know should be going on next week ohh and equal length headers

Nice work. Def be interested in how you go.

[cpitts]

Craig, way too complex to nut out - rpm vs fuel rate for starters and then you'll need the capacity of each cylinder and take into account the volumetric efficiency, boost, amount of burn blah blah

Fair points. But there should be a theoretical power point that can be determined. In a real car everything from exhaust to air filter will impact real power numbers. But in theory, full fuel squirt from injector (560cc) + oxygen (enough to burn the fuel) x volumetric efficiency x # of cylinders should give a pretty good indication of peak Joules of energy that can be produced.

Far simpler to know from experience what the injectors max out at whilst monitoring AFR on a dyno and then I'd only go to a max of 90% duty cycle for some headroom.

I think most people see 80-85% at 170kw so I dont think you'll see 240kw on stock fuel delivery

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.

[SillySora]

Where was all this info when i tried to make a shitty post

[ultrablue]

from autospeed article
Conversions

* 500cc per minute is approximately equal to 49lbs per hour which is equal to approximately 100hp.

* lbs/hour = cc per minute / 10.2

* lbs per hour = HP / 2.04

* cc per minute = lbs per hour x 10.2

* cc per minute = HP x 5

* HP = cc per minute / 5

* HP = lbs per hour x 2.04