Here's one opinion on E85 conversions. Just remember that the raw info came from GM, so it may be a bit biased toward factory flex-fuel cars.

http://www.mpt.org/motorweek/goss/2706.shtml


You most likely will need to increase your fuel by around 10-15% because ethanol contains only about 80% as much energy as gasoline.

 

yeah, thats why I was thinking 850 primary 1600 secondary

just run them at a lower duty cycle.

 

so what's the difference from running your injector duty cycle at 100% or say 75%. I have 550 and 1600 and my primaries are set at 100% and iv'e seen my injectors hit like 92%. Is that to high?

 

Injectors are basically on/off switches. 100% means they are on all the time, where as less than 100% means they are flicking on/off to regulate the amount of fuel.

The main issues is that at 100%, there is no more fuel to give. So if you are lean at 100% duty cycle, you can't simply change your tuning to provide more fuel. However, if you are at 92%, then you still have a little more fuel you could add if you needed it.

 

Though if you're running in to a lean condition above 85% it's pretty much time for new injectors anyway... from what i've read. I thought fuel was hard to tune after that.

 

High duty cycles just mean you don't have room to grow.

 

so it would be better for me if i tuned my primaries down to about 85% and had it re-tuned

 

So long as your boost and AFRs are stable right?

 

they seem good for now...i just have a very rich gas smell coming from the car constantly...not sure what thats about, but maybe my injectors are going bad from constantly running

 

Yes. There is nothing wrong with high duty cycles if your AFR is good.