when you get larger injectors your big issue will be removing fuel! A VAFC has a hard time removing fuel closed loop (partial throttle) because the stock ECU is constantly 'learning' and will change your partial throttle settings. With larger injectors it will be tough to control, especially with a basic tuning setup like a VAFC. i woudl recommend using at least a greddy to control it, but im sure you could get it to work, albeit, it won't run really well.

 

The VAFC doesn't control injector pulse like the F/IC or E-manage. It will either reduce/increase MAP voltage and the stock ECU will compensate injector pulse accordingly. This will be basically impossible to properly tune.

You might be able to pull this off with 440cc injectors if you don't mind an occasional fuel metering CEL due to the rich idle. Basically you would be running pig rich until VTEC. IMO, it's worth the upgrade over VAFC for flexibility in tuning, running higher boost, and controlling ignition timing.

 

I was afraid of this, makes sense.

When you say Greddy unit, you mean the Emanage? Or is there another piggy back unit with vafc style interface that they make?

 

Yeah I was thinking the same thing about possible trying the 440cc but you addressed that hypothetical. Thanks for your input there. I suppose if I had to I could try them, and if it was apparent its not going to fly, then get management. I won't be purchasing anything I wouldn't need this way, but may have the chance at not needing to spend more for management. From what it sounds like 440cc won't handle much more then what i have, so if it turns out I do need management I might be wishing I got the 550cc for up to 10psi right?

 

In essence, this would be like the old days of the 'VAFC hack', right?

I recall turbo'ing my non-vtec Integra, putting 440cc saturated injectors in and a missing link to 'hide' the boost from the MAP sensor and it worked. It wasn't optimal, but, it did work.

I would think this would be a similar situation.

 

[QUOTE=SuzukaBlueAP2,Sep 16 2008, 10:17 AM]
I recall turbo'ing my non-vtec Integra, putting 440cc saturated injectors in and a missing link to 'hide' the boost from the MAP sensor and it worked.

 

You have a wideband O2 gauge? Like you said, you can get the injectors first and see how it works. If you can't get it running properly, then step up to a better tuning solution. I wouldn't run a smaller pulley without a better piggyback though, IMO.

 

[QUOTE=1nate7,Sep 16 2008, 12:03 PM] You have a wideband O2 gauge?

 

Can our ECU w/o an actual piggyback control injectors thats larger than stock??

I was always under the impression that it was not possible, and in order to properly upgrade to larger injectors, you would need some kind of Standalone, or Piggyback?

I'm really hoping this works out for you, this will provide some more options for those of us, that's in the same boat with the stock injectors being maxed out.

 

The maximum injector size you can run without an Emanage or AEM EMS is 440cc. I happen to have a set that I might be willing to trade for stock injectors + cash.

I ran my VAFC II with 440cc injectors for 2 years with my 7 psi CTSC setup.