I am looking at putting a floatless fuel sender unit in my 1965 Dodge Dart. I am looking at the one from Speedhut but also saw them on Summit Racing. I was wondering if anyone had any experience with this type of unit. Thanks for any input
Floatless Fuel Sender
- Thread starter PA65Dart
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pishta
I know I'm right....
how do they work? The float ones for a stock tank are like $26 new on Ebay.
I gotta see this. Link?
What's our ohm range? I am on my phone and can't look it up easily.
toolmanmike - the ohm range will vary depending on your vehicle and gauge (original vs after market). I have the Speedhut fuel gauge so it says I do not need to calibrate it to the Speedhut sending unit. The important thing is the length. I think the 65 Dart is 8 inches, but don't quote me.
694spd
Well-Known Member
From their instruction sheet: (Sender is 240Ω - Empty and 33Ω - Full)
The way I see it, this is a completely different type of unit then the ones we all know.
The capacitance fuel level probe has a attached transmitter to it that requires a continuous 12 volt power source to power it up. this would not be the source that comes from the IVR. The output signal voltage of the transmitter is intended to drives corresponding fuel gauge. I don't believe that it would work with a
factory fuel gauge.
The way I see it, this is a completely different type of unit then the ones we all know.
The capacitance fuel level probe has a attached transmitter to it that requires a continuous 12 volt power source to power it up. this would not be the source that comes from the IVR. The output signal voltage of the transmitter is intended to drives corresponding fuel gauge. I don't believe that it would work with a
factory fuel gauge.
This one is closer to the Ω range.
g413
Well-Known Member
I agree with the above comments that the standard Mopar fuel gage will looking for a sending unit with an 10 - 85 ohm range. So these units will probably need to work with a special gage calibrated for the sending unit. That's okay.
Don't be too concerned with linearity at the "empty" end. On my 67 Barracuda, the first 3 gallons do not count. Then somewhere between 3 and 4 gallons, the suction tube gets completely covered with fuel. Before that, you're just sucking air.
What bothers me is that these units must come in from top of the tank. On the gas tanks that I have dealt with, the top of the tank is firmly mounted (with a rubber pad) right against the bottom of trunk sheet metal. So it seems like you would have to rig up a 3/4" spacer to lower the whole tank to allow this to fit -- not easy. I personally would not drill a hole in the bottom of the trunk.
Don't be too concerned with linearity at the "empty" end. On my 67 Barracuda, the first 3 gallons do not count. Then somewhere between 3 and 4 gallons, the suction tube gets completely covered with fuel. Before that, you're just sucking air.
What bothers me is that these units must come in from top of the tank. On the gas tanks that I have dealt with, the top of the tank is firmly mounted (with a rubber pad) right against the bottom of trunk sheet metal. So it seems like you would have to rig up a 3/4" spacer to lower the whole tank to allow this to fit -- not easy. I personally would not drill a hole in the bottom of the trunk.
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Agreed. My next question was going to be "how are these going to work with our tanks that the senders go in at a angle?"
For our classic a-bodies...
step 1. cut out trunk pan and replace with flat sheet metal to delete the spare tire well.
step 2. replace original fuel tank with alternate tank that fits and is compatible with this type sender.
step 1. cut out trunk pan and replace with flat sheet metal to delete the spare tire well.
step 2. replace original fuel tank with alternate tank that fits and is compatible with this type sender.
They use the same senders in aircraft, basically a tube inside a tube and the fuel gets in between them and creates capacitance, one would work like a champ level driving but will act like a regular float on a angle. The aircraft I worked on had 5-9 in a tank to even it out on climbs, turns etc. They must use a converter to turn the signal into resistance.
Looks like the fuel hut one has it built in to the top, voltage outputs are right where you want them but prob will have to bypass the IVR and go directly to the stock gauge.
Was just saying it looks like 12v goes to the speedhut sender and the reduced voltage comes out unlike ohms in a traditional sender. They are a good way to measure fuel did not have two many go bad only issues we had were the wires coming off the probes, different style for sure.
KitCarlson
Well-Known Member
I read the Speedhut info, the output is 2.33V empty, 0.54V full as continuous signal. It will not be compatible with stock mopar gauges. Speedhut has a gauge for direct use.
A converter to work with mopar gauges using a micro controller, resistor and mosfet is fairly easy. The micro would read the sender voltage, and control a mosfet with a 10 Ohm resistor in series to gauge. The control involves PWM, duty cycle control, that results in perceived resistance increase. Some thing like that would cost under $10, and take a few hours. Might be less than 10 lines of code. I am busy babysitting 11 month old grandson, or I would jump on it.
I always thought to get Del, Pishta, or Rainy Day Auto, or others using micros .... perhaps this is a chance. I am here to help, but my hands are busy.
A converter to work with mopar gauges using a micro controller, resistor and mosfet is fairly easy. The micro would read the sender voltage, and control a mosfet with a 10 Ohm resistor in series to gauge. The control involves PWM, duty cycle control, that results in perceived resistance increase. Some thing like that would cost under $10, and take a few hours. Might be less than 10 lines of code. I am busy babysitting 11 month old grandson, or I would jump on it.
I always thought to get Del, Pishta, or Rainy Day Auto, or others using micros .... perhaps this is a chance. I am here to help, but my hands are busy.
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