Big Fuel Pump Ok To Run On Stock 5.0?

[Gordo110]

How's it going everyone, wanted to get some inputs here, pretty soon I'm going to purchase the Trick Flow top end kit, but wanted to change the fuel pump because it's whining badly, and because of the upgrades I'm doing soon, my question is....would it be fine to run a 255 fuel pump with a stock 5.0? Only have exhaust at the moment. Any input would help, thanks!

 

[88LX5.Oh]

What are the future mods? If you plan to boost it later on, yeah go for the 255.
If you just plan to do a nice HCI swap and call it quits, then I wouldn't do it. The 255 will cause the fuel to circulate through the system a lot more than smaller pumps. As the fuel circulates, it picks up a lot of heat and can evaporate off.

 

[Gordo110]

Just finished the longtubes and exhaust, going to be doing the tf top end kit, 75 mm tb, 24lb injectors, fuel rail, 373's, and so on, but yes future plans are to boost, I just wanted to see if it would be a problem running a big pump now, thanks for the quick response oh!

 

[88LX5.Oh]

Just finished the longtubes and exhaust, going to be doing the tf top end kit, 75 mm tb, 24lb injectors, fuel rail, 373's, and so on, but yes future plans are to boost, I just wanted to see if it would be a problem running a big pump now, thanks for the quick response oh!

No problem Gordo!
If I were in your place, I would go ahead and do the 255 because there's no sense to me to buy lets say a 190, then shortly after you'd have to upgrade to the 255. 2x the money spent and 2x the time taken up.

Plus there's plenty of people that run HCI combos with a 255. Yes it's over kill but you won't see any negative effects except for maybe a little bit poorer fuel mileage. But, you're modding a Mustang. Who needs fuel mileage

 

[Gordo110]

hahaha, ya got that right, its only my nice weather, weekend driver anyways, fuel mileage isn't a big deal, just wanted to make sure I wasn't going to open a can of worms with the 255 pump, thanks again Oh, your a big help

 

[88LX5.Oh]

hahaha, ya got that right, its only my nice weather, weekend driver anyways, fuel mileage isn't a big deal, just wanted to make sure I wasn't going to open a can of worms with the 255 pump, thanks again Oh, your a big help

You're welcome

 

[NIKwoaC]

I've heard it before, but I'm not sure that I subscribe to the theory that the bigger pump creates any sort of a measurable fuel heating problem. I think it's mostly just speculation, because lots of guys run 255s on the street without any problems.

 

[RacEoHolic330]

I agree that a 255lph pump can't produce enough heat to affect the fuel, but the very large pumps (for 1000hp and up) can easily boil the fuel if used on a street setup without a controller of some sort. They can even implode a gas tank that is not adequately vented. Those things move serious volumes of fuel.

 

[Noobz347]

I've heard it before, but I'm not sure that I subscribe to the theory that the bigger pump creates any sort of a measurable fuel heating problem. I think it's mostly just speculation, because lots of guys run 255s on the street without any problems.

I agree that a 255lph pump can't produce enough heat to affect the fuel, but the very large pumps (for 1000hp and up) can easily boil the fuel if used on a street setup without a controller of some sort. They can even implode a gas tank that is not adequately vented. Those things move serious volumes of fuel.

Dudes... it's not the pump that creates the heat. It's running all that fuel through the engine bay, by-passing the fuel regulator through the fuel rail, and returning to the tank... over and over and over...

I do agree though, that the pump should not be matched to your current setup but instead to your end-game setup. If boost and 300+ RWHP over large-ish injectors are your ultimate goal then yes... swap the pump just one time.

NOBODY who's running a Mustang should ever run a 190L fuel pump unless it's a HIGH PRESSURE 190L fuel pump.

 

[RacEoHolic330]

You're right Noobz, all that fluid flow does generate heat. The pump itself still does contribute to the heat soak of the fuel system. General rule of thumb is if the pump is uncomfortably hot to the touch, it's too hot and the fuel is prone to vaporizing.

 

[Noobz347]

You're right Noobz, all that fluid flow does generate heat. The pump itself still does contribute to the heat soak of the fuel system. General rule of thumb is if the pump is uncomfortably hot to the touch, it's too hot and the fuel is prone to vaporizing.

Doesn't help that all that gas has to thread gambit of a set of heat soaked fuel rails either.

 

[NIKwoaC]

Dudes... it's not the pump that creates the heat. It's running all that fuel through the engine bay, by-passing the fuel regulator through the fuel rail, and returning to the tank... over and over and over...

I do agree though, that the pump should not be matched to your current setup but instead to your end-game setup. If boost and 300+ RWHP over large-ish injectors are your ultimate goal then yes... swap the pump just one time.

NOBODY who's running a Mustang should ever run a 190L fuel pump unless it's a HIGH PRESSURE 190L fuel pump.

My post wasn't very clear, but yea, I understand what you're getting at. Just not sure that it's a terribly significant issue for a 255 on a mild-ish street build.

 

[88LX5.Oh]

NOBODY who's running a Mustang should ever run a 190L fuel pump unless it's a HIGH PRESSURE 190L fuel pump.

Damn damn damn...
I hope mine was a high pressure one.


EDIT:
http://www.summitracing.com/parts/VPN-GCA710-2/
IT DOESN'T SAY

 

[gearheadboy]

Dudes... it's not the pump that creates the heat. It's running all that fuel through the engine bay, by-passing the fuel regulator through the fuel rail, and returning to the tank... over and over and over...

I do agree though, that the pump should not be matched to your current setup but instead to your end-game setup. If boost and 300+ RWHP over large-ish injectors are your ultimate goal then yes... swap the pump just one time.

NOBODY who's running a Mustang should ever run a 190L fuel pump unless it's a HIGH PRESSURE 190L fuel pump.

And why should you NOT run a 190?

 

[88LX5.Oh]

h

And why should you NOT run a 190?

He's explained it before. I think he has said something about the 190's being more prone to messing up and jumping up to ridiculously high pressure. I can't remember completely

 

[gearheadboy]

I gotta hear this.

 

[Noobz347]

Damn damn damn...
I hope mine was a high pressure one.


EDIT:
http://www.summitracing.com/parts/VPN-GCA710-2/
IT DOESN'T SAY

From what I can find, the pump in that kit is a Walbro GSS242. It's low pressure.

The high pressure pump is GSS341 and it's not generally marketed for the Mustang. It's marketed for the probe.

All is not lost however... So long as you don't run boost. If you get to the point where you want to then I would suggest changing your pump.

 

[Noobz347]

I gotta hear this.

The low pressure 190s tend to internally by-pass at or near 60 psi. Some a little more, some a little less. So boosted apps, apps using an FMU or really large injectors (where fuel pressure builds in the line before even getting the rails), they can be unpredictable.

 

[88LX5.Oh]

From what I can find, the pump in that kit is a Walbro GSS242. It's low pressure.

The high pressure pump is GSS341 and it's not generally marketed for the Mustang. It's marketed for the probe.

All is not lost however... So long as you don't run boost. If you get to the point where you want to then I would suggest changing your pump.

If I ever do run boost I would want a bigger pump anyways just to be safe so we're good!

What exactly is it about the low pressure 190's that's bad for boost?

EDIT: typed it out a little too late lol

 

[Noobz347]

You pretty much have to go out of your way and know what you want ahead of time, to get a high pressure 190. Summit doesn't even list the Prob compatible pump as a Mustang usable part.