Fuel injector question

[Jersey Big Mike]

As winter approaches I start once again to start planning to work on a overdue project. A true gas gauge for the K-9 (I'll probably replace the entire dashboard -speedo, mileage, tech etc by the time I'm done.)

What I was wondering, does anyone know the g/s (grams/second) on the injectors in a K-9. KNowing this and fuel weight I can calculate fuel usage ie resetable fuel gauge. Hell could even give live MPG.

thanks in advance.
Mike

 

[Sven]

I think if you can read the code numbers off the injector it gives you the flow per minute of the body, spray holes, etc.

 

[Jersey Big Mike]

I think if you can read the code numbers off the injector it gives you the flow per minute of the body, spray holes, etc.

was trying to figure it out without pulling them off the bike. But good to know.

 

[KaptinAmerika]

34.8 lbs/hr or 4.838319 grms/sec

 

[Jersey Big Mike]

34.8 lbs/hr or 4.838319 grms/sec

thanks. Will make it easier than guessing and doing a number of trial runs while still replying on the idiot light.

 

[desertdawg]

The injectors are controlled via ECU which determines pulse width based on all operating parameters of each EFI component. I'm thinking this project of yours is going to require a smart gauge that uses PROTUNE to extrapolate fuel consumption. Todays injected cars still use the tried and true sending unit that incorporates a float.

 

[Sven]

Todays injected cars still use the tried and true sending unit that incorporates a float.

I'm sort of semi obsessed with FI so I'm curious what this tried and true unit is? Is this the MAF sensor? I thought the tried and true is the alpha formula when all sensors drop out of the loop, meaning, it calc is off of the 1 ATMO, or digital single?

 

[Sven]

If you're going for accuracy then you'd have to factor in how many times you lift coasting and how much fuel was used. It's not a flat out fuel cut or you'd nose the front end... like hitting the kill switch.

 

[awg]

Well.....what gives better gas milage. A carb or a fuel injected motorcycle?

 

[mleach72]

Well.....what gives better gas milage. A carb or a fuel injected motorcycle?

Theoretically, it shouldn't matter. Best fuel mileage occurs at an air/fuel ratio around 14.3-14.5:1, no matter how the fuel is being delivered. With that said, it may be much easier to achieve this afr with FI because of o2 sensors and fuel maps. With a carb, it's a little more difficult. With an S&S carb, you use the correct jets for best performance, and unfortunately you are stuck with whatever fuel mileage that delivers. On a mikuni, there is a bit more tuning ability. The cruise range on the carb can be zeroed in for best mpg without having an affect on acceleration ranges.

 

[awg]

Very good. Thanks.

 

[Sven]

Well.....what gives better gas milage. A carb or a fuel injected motorcycle?

FI. If the better gas mileage was a carb, we'd still be using them. Gotta remember, every suck on a carb when starting is the same fuel out the holes when it does not turn over. FI; it starts right up reading air temp/water temp/cam position/pressure of the moment. etc.

I'm going to recall from memory:
11:1 ~ Too Rich - used for rich dumping, meaning, mimicks an accelerator pump on WOT or heavy load
12:1 ~ Ideal Smooth rich torque
13:1 ~ A lean rich
14:1 ~ All around performance
15:1 ~ Lean
16:1 ~ Ideal mileage
17:1 ~ 22:1 Lean cuts off throttle if not full lift... cuts of fuel entering, but not completely shuts off, or hit the kill switch and note the difference.

Direct Injection Engine Efficiency | HowStuffWorks

auto.howstuffworks.com › ... › Engines › Types of Engines

Direct injection engines use a mixture of 40 or more parts air to one part fuel, written as 40:1. That compares to a normal gasoline engine's mix of 14.7:1. A leaner mixture allows fuel to be burned much more conservatively.

When a main parameter sensor drops out of the loop, a method is applied. One method is calc'd as a/N or alpha numeric and D/J for digital jetronics. One is a heavy load vs rpm, and the other is light load vs rpm. It is now called open loop or aims for the one atmosphere/101.3pa/760mmHg.

The 02 is a sustain reader. Meaning, you cruise with the sustained throttle, the 02 is running ideal preset AFR = 760mmHg. Better known as closed loop. So say you code one of the main sensors that sends input in for said FULL Power (no codes) map. The bike goes limp to a new map to save the engine from damage. You just set the bike into method. Wanna run for pink slips LOL.

 

[awg]

Man....my head is still spinning!

 

[Sven]

No one was answering my questions so I went on a mission to understand what I was asking. Whatever research I came across, I then ran a medical pressure gauge that reads in mmHg. When you see the pre-pressure readings off the 760mmHg, it does not show you that on the close of the intake, the constant number remains at 760mmHg no matter the air to fuel ratio entering the chamber. Therefore, I am assuming when that vac sensor drops out of the loop, the 14.7/101.3/760mmHg uses the 1 atmosphere to calc out the dropped out parameter. The 'Huston, we have a problem' is when the method kicked in on the computer. Another way of saying backup/fail-safe/limp mode.

"Todays injected cars still use the tried and true sending unit that incorporates a float. " WATT sending unit is this? I think I can hold my own on FI so if the net is going to apply a sending unit (sensor) as a float, it's still 14.7 pressure on top of that fuel in the float = Method (760mmHg/14.7/101 intro to FI).

Like trying to snow the snowman...

 

[Sven]

My answers came off these type bikes. Kept crashing, kept researching. I made a wire harness and had it too close to the throttle wheel and got hooked on the throttle wheel and got stuck open. Anyway, the hacked wire is now in limp mode or reads a constant 'digital' number. The stock, untampered computer bike has a different 'analog' sound than it's backup sound. So bottom line... Don't fuck with a computer bike or it goes limp performance wise.

Autotune is capturing the output signal to the injectors, and then sends the new injector time opening to the injector. My point is... just knowing you try to mess with FI, don't think inside it can't calc itself out to the 'best number' calc'd according to the inputs. Mess with one and you go limp. No point using a fuel enhancer unless you want to flip to a 16.1 AFR map and cruise all day long.

If you are looking for better gas mileage, my MO is to turn the engine off at traffic lights. That's less hours on the engine, less gas being used up sitting and waiting. Happy calc'ing gathering all those variables.

 

[mleach72]

Anything over 15:1 afr is going to start melting your engine. I don't think an engine would even run at 16:1. If it did, it would be coughing and pinging like crazy, and would be putting off enough heat to melt the hair on the inside of your legs.
A finely tuned carb can deliver just as good fuel mileage as FI. The big advantage of FI that a carb can't match is throttle response. Fuel is delivered independently of vacuum in the throttle body. With a carb, fuel is completely dependant on vacuum.
Whether you have FI or a carb, the goal numbers remain the same. Best afr for acceleration is about 13:1. Best idle is 13.2:1. Best fuel mileage is around 14.3-14.5:1. This isn't my opinion. These numbers are pretty widely accepted everywhere.

 

[Sven]

Anything over 15:1 afr is going to start melting your engine. I don't think an engine would even run at 16:1. If it did, it would be coughing and pinging like crazy, and would be putting off enough heat to melt the hair on the inside of your legs.

Here is a 16:5 AFR test run. No heat, no melt. The other vid showed the last saved AFR when the key was turned off, and that was a 15 AFR test run. I stopped testing at 16. If you research Smokey Yunick, he set his NASCAR engines at 14:1.

Fuel is delivered independently of vacuum in the throttle body.

FI is load based so the intake air pressure sensor is plumbed for each cylinder. Throttle position and rpm are your 3 key inputs. Lose the pressure you go limp. Lose the throttle position, you still hit method. Lose crank sensor, you now have a boat anchor. So technically you're right, but it will run limp, backfire, buck, kill the engine without the IAP sensor... ask me how I know.
Hacked sensors that go limp but have a backup to keep running :
Water temp = Runs too hot.
TPS = Runs, but goes limp.
Stepper motor = Runs.
Gear position = Runs.
IAP = Runs but is not rideable, but can be limped to the dealer.
Intake air temp = Runs.

 

[mleach72]

Here is a 16:5 AFR test run. No heat, no melt. The other vid showed the last saved AFR when the key was turned off, and that was a 15 AFR test run. I stopped testing at 16. If you research Smokey Yunick, he set his NASCAR engines at 14:1.

FI is load based so the intake air pressure sensor is plumbed for each cylinder. Throttle position and rpm are your 3 key inputs. Lose the pressure you go limp. Lose the throttle position, you still hit method. Lose crank sensor, you now have a boat anchor. So technically you're right, but it will run limp, backfire, buck, kill the engine without the IAP sensor... ask me how I know.
Hacked sensors that go limp but have a backup to keep running :
Water temp = Runs too hot.
TPS = Runs, but goes limp.
Stepper motor = Runs.
Gear position = Runs.
IAP = Runs but is not rideable, but can be limped to the dealer.
Intake air temp = Runs.

You may be able to get away with those numbers on a computer-controlled water-cooled engine, but on an air-cooled American v-twin, those afr's are going to cause damage. Harley has to run afr's near 15:1 to pass emissions, but they had a hard time keeping the engines cool. That's why they started going with the water-cooled heads.