Greddy vs HKS vs AVO - Opinions on bang for buck

[Inf3ct0R]

ah right.... I assume your running stock injectors with the other four? is there a reason why ya didnt opt for 550cc injectors straight up/

[Sean]

ah right.... I assume your running stock injectors with the other four? is there a reason why ya didnt opt for 550cc injectors straight up/

Often (depending on what ECU you use) the second set of injectors are staged to come in under certain conditions, works kind of like vacuum secondaries on an old carby if you've ever played with them.

This can often (again ECU dependant) make it easier to achieve smooth idle with acceptble emissions on light throttle.

[Woo]

Couldn't have said it better Sean

I recall reading somewhere (may have been Corkey Bell) that injectors tend to dribble rather than spray at low duration pulses (needed for idle). This would be more pronounced the larger the injector.

I'm yet to realise anywhere near the kW that would require anymore fuel than what it's already getting. Injectors run a gaussian efficiency curve (as most things do ;) ) so it's a bit pointless imho to be outside the optimal operating range of the component.

Having said that if you overlap two gaussian curves (two sets of injectors) you reach a point (the Raleigh critera) where the two curves appear as one broad one and are now 1.5+ times the width of a single curve (one set of injectors). You can then adjust the combination of the two to provide a optimum fuel delivery to deliver linear torque.



As you can see the extra injectors start taking off at 3250 RPM and my fuel pump let me down after 55000RPM. I've since replaced the pump with a Walbro 255lph
So if you extrapolate the curve to remove the kink at 6k, next time I tune I should be looking at 190+ possibly


Wòó

[mossy]

So if you bought the AVO kit minus electronics and say a WOLF 3d do you just replace the factory injectors with larger ones (440 or 550??) and could you expect better power than with the link system?

[Sean]

So if you bought the AVO kit minus electronics and say a WOLF 3d do you just replace the factory injectors with larger ones (440 or 550??) and could you expect better power than with the link system?

As long as you can adjust the fueling and timing (and you have the right amount of both) either system should produce the same power.

I suspect the reason for AVO choosing to go with a secondary set of injectors is to get passed emissions.

[ZenArcher]

Great information. Thanks everyone. Keep it coming, especially more dyno sheets.

OK.

So the Greddy kit turbo is not a ball bearing turbo.

My plan was IF, I go the Greddy, I was going to get it intercooled. But what is a good computer for the timing? I notice a lot of the guys in the USA are using a BIPES. to control timing. How good are these and are they available in Australia?

Kula - you said shopping around, the Greddy can be had for under 2K. Mind telling me where? Everywhere I have phoned and seen on websites, are mostly just under 2.5K