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120 lb/hr injectors, E85, duty cycle

Posted: Wed May 19, 2010 8:56 am
by wallace
I have been running this car for several months now and have started to turn up the boost level and the duty cycle is now showing 89% at about 18 lbs boost. I'm using MSII. The PW at this level is shown as 17.28 I altered the size of the injectors to 72 lb/hr to compensate for the addtional volume that the E85 requires. I've logged fuel pressure and it is not dropping off and rises 1 to 1 with the boost. I had the 120's flowed before running the car and the lowest of them was 1155 cc's. Am I really out of injector at this point or is the duty cycle skewed by the injector sizing being incorrect. Combo is:
231 cid v6
72 mm turbo
120 lb/hr injectors
EDIS-6
Any information or help is appreciated. thanks.

Re: 120 lb/hr injectors, E85, duty cycle

Posted: Wed May 19, 2010 7:14 pm
by drmiller100
duty cycle from megatune should be real duty cycle.

ethanol is weird stuff. Theory says if you throw more and more ethanol fuel at an engine, it should just make more and more power, and run obnoxiously rich still making more and more power.

do you have a wide band 02 sensor on it?

one idea might be to add a couple of injectors just behind the turbo which only squirts when boost goes over 5 psi. They would be additional fuel.

Re: 120 lb/hr injectors, E85, duty cycle

Posted: Thu May 20, 2010 3:32 am
by wallace
Not true on going richer. It acts just like gasoline if you go too fat it breaks up. It is so much more knock resistant than gasoline. So my next step then is to raise the base fuel pressure to extend my range a bit. Sucks I was sure the 120's were going to be enough.

Re: 120 lb/hr injectors, E85, duty cycle

Posted: Sun May 23, 2010 5:37 pm
by elturbonitroso
that happen to me a while back and i solve the problem contacting the injector manufactor and ask them for the injector dead time and problem solve duty cycle down and a much better idle.hope that help