Bigschwerm

iTrader: (26)

My setup is in my signature

Im going to jump up to 31lb 8.1L injectors and keep my stock pump.

Do you think this will support E85 on my 5.3l N/A ?

I recently started running a 20% mix of e85 and the truck likes it.

KLUG'S SS

iTrader: (6)

No. The stock pump I have found to be fine on E85 but even n/a on a heads/cam setup like yours the 8.1 30 lb/hr injectors surely won't be enough.

hog

Dont flex injectors flow 32 lb/hr?

Here is an IFR vs vacuum chart from an 8.1.
0 kpa 3.703=29.4 lb/hr
5 kpa 3.727
10 kpa 3.750
15 kpa 3.773
20 kpa 3.797
25 kpa 3.820
30 kpa 3.844
35 kpa 3.867
40 kpa 3.891
45 kpa 3.906
50 kpa 3.930
55 kpa 3.945
60 kpa 3.969
65 kpa 3.992
70 kpa 4.023
75 kpa 4.055
80 kpa 4.078grams/second= 32.4 lb/hr

peace
Hog

KLUG'S SS

iTrader: (6)

Their is the static flow rate of injectors and then their is the dynamic flow rate of injectors. The static flow rate of an injector is the maximum output of the injector at a given pressure and what is used to classify the injector. The static flow rate is what you'll see at the 0 kpa cell on the IFR table in a tune file and is what you would get if that injector was sent off to a place like FIC to be flow tested on the bench.

The dynamic flow of the particular injector for example as you have listed above where we have 32.4 lb/hr at 80 kpa is not how or what that injector is rated at.

hog

Thanks.

For the table I listed above, isnt the purpose of this dynamic FPR table to substitute for a vacuum referenced FPR?

I notice in the older PCM's in VRFPR apps, that only the static IFR is used.

thanks
peace
Hog

KLUG'S SS

iTrader: (6)

No problem man, I have found it at times to be a somewhat common misconception for some when it comes to static flow rate vs dynamic flow rate.

Yes in the case of the 99-03 trucks for example where they utilize the "return style" fuel system with the regulator mounted on the fuel rail the regulator's job is to maintain the same pressure drop across the injectors. In which case is why you will find when you look at the tune file of a truck using the "return style" system that the IFR table remains constant across the board from 0 kpa - 80 kpa as well as the injector offsets vs battery voltage table's values also remaining the same across the board from 0 kpa - 80 kpa.

The return style systems make life A LOT easier on the tuner especially in cases where for example a customer gets ahold of me for a tune where the injectors have been swapped in the vehicle to a set of injectors that lack the full compliment of data for them. Solving backwards for the injector data as I like to call it to get the vehicle running well in the shorter pulsewidth areas such as idle, decel, etc..... is less of a headache when a return style fuel system is being used.