I have searched but maybe i havent searched the correct terms so not 2 manny flames please.

I have a 13b peripheral port and have decided im goning to be running it on e85 so to start with i need lots of injector.

I have decided to have my primarys as 1680's as well as my secondarys so 4 x 1680.

Im wonrderin if anyone has run 1680's as primarys before and is so give me a few starting blocks.

Ideally im looking for a 13b pp map running 1680's all round but even a bridge map running the same would be good.

No telling me not to run 1680's as primarys as the work has already been dun and the injectors are in place.

So all input is welcome.

Steve

 

Btw this engine is new so it has not run yet

 

The only problem with the very large injectors, will be to lean them out for idle.
Use the lag adjustment to do it even if it requires negative lag. This will only mess up the calculated injector duty cycle and not maximum flow through the injector.

850s require about -.04 lag.

(1680 / 850) = 1.98, 98% more flow
(125000/90490) = 1.38, 38% more flow needed for E85 over gasoline

Thus you will need a large negative lag to lean out idle.

 

Thanx Chuck, managed to get it started tonight, had to pull a lot of fuel as i under estimated just how much fuel it would use during cranking, also pulled lots out of the cranking map as well.

ticks over about 2k atm but may manage to get that down to 1600 with a little effort

gonna be getting afr's about 12.5 at tickover then start working with the cold start map from cold

 

Sorry but I did not explain this one and it may not be obvious to some.

An easy way to figure comparative fuel requirements between different fuels is
by BTUs. The same BTUs are required to make the same power regardless of the AFR differences.

125,000 btus for 1 gallon of gasoline (no ethanol added).
90,490 btus for 1 gallon of E85.