Injector Calibration

[E85Pete]

I am converting my 2004 Grand Am (3400) over to E85 full time.

I need a little help with injector calibration.
I replaced the stock 22 lb/hr injectors with 28 lb/hr Trailblazer injectors.

Can anyone tell me what the actual ratings are for these two injectors so I can let the ecu in on it?

I found the convertion spreadsheet, but I am unsure what the values should be.
specifically the fuel rail pressure/flow rates.

Thanks

-Pete

[JerryH]

Your tune will tell you. If previously your trims were well dialed in, you want the same trims as before.

Since E85 is consumed at around 30-31% faster than fuel, it would be wise to increase your IFR by that amount. Since you went from 22 to 28 lb injectors, that is about a 30% increase. My suggestion? Start off from the tables you have now, and see what your tune tells you!

BTW, do the safety stuff first. E85 is corrossive as hell. It eats through many plastic gas tanks, fuel lines and things like the gaskets inside your fuel pressure regulator unless it was made to run on it. I hope you took those things into consideration before the tuning aspects... it's certainly more important.

[98gtp]

I would find a .hpt file for said vehicle and copy and paste. then tune your maf to accomodate for new fuel.

[98gtp]

BTW, do the safety stuff first. E85 is corrossive as hell. It eats through many plastic gas tanks, fuel lines and things like the gaskets inside your fuel pressure regulator unless it was made to run on it. I hope you took those things into consideration before the tuning aspects... it's certainly more important.

while e85 is corrossive, it does not eat plastic tanks, it will eventually 'rust' a metal tank from the inside. but plastic tanks are the safe tank when it comes to E85. the only other major items that has been run into with going from gasoline to straight E85 i've seen is the fuel filters, they need to be replaced about 7 times as often, or make a flex fuel filter fit(like off that trailblazer)

[JerryH]

As long as you checked (rubber hosing is particularly susceptible... X2 if any water gets into your fuel system... you will see a much faster build-up of methanoic acids in your system).

Do everything to keep water out of the fueling system. Also, with ethanol contaminated with higher amounts of water (for example, approximately 11% water, 89% ethanol, equivalent to 178 proof ethanol), considerable engine wear will occur, especially during times while the engine is heating up to normal operating temperatures.

A little something that may help out your settings:

----- Fuel ----- ----- AFRst ----- FARst ----- Equivalence ----- Ratio Lambda
Gasoline stoichiometric ----- 14.7 ----- 0.068 ----- 1 ----- 1
Gasoline max power rich ----- 12.5 ----- 0.08 ----- 1.176 ----- 0.8503
Gasoline max power lean ----- 13.23 ----- 0.0755 ----- 1.111 ----- 0.900
E85 stoichiometric ----- 9.765 ----- 0.10235 ----- 1 ----- 1
E85 max power rich ----- 6.975 ----- 0.1434 ----- 1.40 ----- 0.7143
E85 max power lean ----- 8.4687 ----- 0.118 ----- 1.153 ----- 0.8673
E100 stoichiometric ----- 9.0078 ----- 0.111 ----- 1 ----- 1
E100 max power rich ----- 6.429 ----- 0.155 ----- 1.4 ----- 0.714
E100 max power lean ----- 7.8 ----- 0.128 ----- 1.15 ----- 0.870

I tried to format it so that it is somewhat readable.

[98gtp]

just to note, those max power numbers are for NA cars, even the Max Rich numbers are to lean for a Boosted application.

[JerryH]

Yup, but good as a starting point. Drop about 0.8-1 for forced induction maximums.

[E85Pete]

Thanks guys, I can take it from here.