FFI Platinum Flex fuel kit

[jn2630]

Does anyone have any experience with this flex fuel kit? http://www.change2e85.com/servlet/Detail?no=137

[mendelmax]

Correct me if I'm wrong, but to my taste it does nothing. It has no input from either gasoline density or O2 sensors, so it can't really adjust injectors timing to the fuel properly, since it doesn't really know what the ethanol % is, and it has no effect on spark timing. So what it really does, except for keeping injectors opened longer?

I bet nothing more than that, so in that case, wouldn't it be better to just get bigger injectors?

[jn2630]

Simply put, to run ethanol, there must be a richer mixture than gas right, or is there more to it than that? On strait ethanol, I know that the engine will run too hot because its too lean, but if that problem is corrected by either fuel injectors open longer, or bigger fuel injectors, will everything be good?

[mendelmax]

But theoretically, the engine will self adjust anyway, since o2 sensor will let it know it runs lean. The problem is that injectors have to deliver approx. 20% more fuel, which is sometimes beyond their limits, but simply elongating pulse width won't do much. Especially at a price of $400 I consider it to be very overpriced "conversion".

I think changing injectors will deal with the problem, but there are also other factors- we can't be 100% sure if fuel system is ethanol-resistant, we can't do anything about spark timing.

I personally think, that there is a reason why FF engines are sold as FlexFuel. If elongating the injectors pulse would be everything that engine needs, most manufacturers would do it right away when E85 is so popular. Not doing it with obvious sale benefits indicate, that there are other problems in the way.

[jn2630]

I emailed them some questions and this is the info that they sent me:

"You need to do a 50-50 in the beginning to allow the vehicle's computer to
make new fuel trim maps with the kit on. You can run straight gas, straight
ethanol, or any combination of the two in subsequent fill ups. If you are
going to run gasoline for extended periods of time, you can remove it - or
put a toggle switch on the ground wire or disconnect the ground wire.
Turning it off may help eek out a little better mileage on gasoline.

Our converter works in concert with your vehicle's fuel trim system.
Flex-fuel vehicles have
a fuel trim system with more capacity for positive trim than the positive
trim capacity in a
non flex-fuel vehicle. By inserting a digital signal processor and some
electronics between
the ECM and the injectors, we can add some positive trim to help the non
flex-fuel vehicle
reach the amount of positive trim necessary for correctly using ethanol.
This added trim,
combined with what the ECM can provide, allows the ECM to trim the fuel to
reach the
proper mixture for E85. Our converter has an internal adjustment which
allows it to be
tuned to each vehicle and the range of fuels typically being used. We have
found that a
setting of about 60% of the converter's positive trim works very well for
the vast majority of
vehicles and ship converters set to this level."

[mendelmax]

Which simply means "buy bigger injectors instead"

[Jeep4xb4u]

Correct me if I'm wrong, but to my taste it does nothing. It has no input from either gasoline density or O2 sensors, so it can't really adjust injectors timing to the fuel properly, since it doesn't really know what the ethanol % is, and it has no effect on spark timing. So what it really does, except for keeping injectors opened longer?

I bet nothing more than that, so in that case, wouldn't it be better to just get bigger injectors?

This is more of a general question that I have always been curious about, but could you just use a adjustable spark timing box on top of a new ignition module. Like the ones you can by for the MSD 6al.

http://summitracing.com/parts/MSD-8680/

[StroktWJ]

Correct me if I'm wrong, but to my taste it does nothing. It has no input from either gasoline density or O2 sensors, so it can't really adjust injectors timing to the fuel properly, since it doesn't really know what the ethanol % is, and it has no effect on spark timing. So what it really does, except for keeping injectors opened longer?

I bet nothing more than that, so in that case, wouldn't it be better to just get bigger injectors?

This is more of a general question that I have always been curious about, but could you just use a adjustable spark timing box on top of a new ignition module. Like the ones you can by for the MSD 6al.

http://summitracing.com/parts/MSD-8680/

I was thinking the same thing! I used to use a MSD multi-step retard box on my LT1 Fbody when I used the bottle.

I would love to give E85 a shot in my WJ!