Silencing electric fuel pumps

[CalSgt]

Has anyone ever put some sound deadening/dampening material on their gas tanks? I was wondering if a small chunk of dynamat on the top of the tank would reduce some of the fuel pump whine. I'm in the middle of my frame off build & noticed how loud they are while the truck is idling, I suppose once the the bed is on it will possibly hide some of the noise.

 

[Tank6x2]

You could use it as an excuse for the wife to buy a supercharger… just saying

 

[CalSgt]

You could use it as an excuse for the wife to buy a supercharger… just saying

LOL... That's pretty good, and for my daily I would probably need to Mansplain why it needs a custom air pump to run right but the boss gave me a blank check for the square build. My goal and reason for going EFI was to make it a reliable no hassle vehicle.

https://www.gmsquarebody.com/threads/80-k-10-squircle-build.34732/

 

[Tank6x2]

Isn’t that the truth!

 

[Hunter79764]

I'll show my ignorance here, I don't have experience on truck tanks, but if it has straps, are the insulators on and installed properly? If they are direct mounted, is there an insulator there? I'd think some dynamat or similar would help, maybe on the underside of the bed instead or as well? On the bed would give and added benefit of absorbing some general road noise and "tinniness" that might be there otherwise. I'd also be looking at the lines and make sure they aren't passing vibration to other areas, i.e. make sure you have flex line to absorb the vibrations before you anchor to the frame rail.

Just curious, what kind of pump and how much HP are you making?

 

[DoubleDingo]

On my Jeep Cherokee there is a ballast resistor to quiet it down. It gets full voltage for startup and then the current runs through the resistor. I have had to hard wire it to diagnose an issue with the fuel pump, and it is louder without the current going through the resistor. May be an option, but you'd need to wire it correctly with relay(s).

 

[CalSgt]

I'll show my ignorance here, I don't have experience on truck tanks, but if it has straps, are the insulators on and installed properly? If they are direct mounted, is there an insulator there? I'd think some dynamat or similar would help, maybe on the underside of the bed instead or as well? On the bed would give and added benefit of absorbing some general road noise and "tinniness" that might be there otherwise. I'd also be looking at the lines and make sure they aren't passing vibration to other areas, i.e. make sure you have flex line to absorb the vibrations before you anchor to the frame rail.

Just curious, what kind of pump and how much HP are you making?

Thanks for the ideas.

They're both standard 66 PSI submersible pumps (one in each tank), stock replacement pumps for a '98 K-1500. I'm only running a stock rebuilt Vortec 350 which was rated for 230 HP @ 4500 RPM in 1998 when it was the standard truck motor.

Brand new saddle bag tanks & brand new strap insulators. There is some flex line between the sending unit and the switch valve and the lines from the valve up to the engine are all flexible Earl's Vaporguard lines.

I do plan to spray the bottom of the bed with Raptor Liner bedliner which should add a small amount of dampening to help with tinniness.

On my Jeep Cherokee there is a ballast resistor to quiet it down. It gets full voltage for startup and then the current runs through the resistor. I have had to hard wire it to diagnose an issue with the fuel pump, and it is louder without the current going through the resistor. May be an option, but you'd need to wire it correctly with relay(s).

Interesting... I'll read up on this. Thanks.

 

[Hunter79764]

That's why I was asking about pump and HP. You could run it at reduced voltage until you get to a certain load point or pressure or something and then it kicks to full voltage. Basically the same idea as a Boost-a-Pump, but in reverse.

Sounds like you have done the right stuff so far, I'm guessing with the bed on it should be a lot less noticeable.

 

[TotalyHucked]

I've had 5 different pumps in my truck and they all are somewhat loud. You can definitely hear it when you first turn the key but once the truck is fired up, you can just barely hear it unless I've run the tank super low. Then it gets real loud. I don't think there's really any way around it.

 

[CalSgt]

I've had 5 different pumps in my truck and they all are somewhat loud. You can definitely hear it when you first turn the key but once the truck is fired up, you can just barely hear it unless I've run the tank super low. Then it gets real loud. I don't think there's really any way around it.

Maybe that's my problem... There's only a few gallons of gas in each tank so I could test the system and get the engine started.

 

[TotalyHucked]

Maybe that's my problem... There's only a few gallons of gas in each tank so I could test the system and get the engine started.

Yep, more fuel definitely helps quieten it down

 

[yevgenievich]

I run pwm controller that is referenced by map sensor on one of the vehicles to get pump to lower output at low load.

 

[SquareRoot]

EP381 pumps in my tanks. Silent. All new factory setup.

 

[mtnmankev]

Not great suggestions, but run either straight pipes for the exhaust or install a loud stereo.

 

[TPISly-C10]

EP381 pumps in my tanks. Silent. All new factory setup.

same here no noise!