Coyote Tuning - Larger Fuel Pump?

[flip1216]

Hey gang,

I recently reached out to Lund Racing to get a custom tune for the Gen II Coyote I have installed in my roadster (getting closer and closer to finishing her up and getting her on the road). While giving the specs of the car, the fuel pump came up. I told the rep that my fuel pump is 190 lph. His reply was:

"The 190 lph is super tiny and less than what a stock coyote has. I would shoot for something like a 400 lph in size."

To which I questioned: "Will the smaller pump limit the tune?"

To which he finally replied: "The 190lph is probably too small for us to tune it at WOT. I've seen them come in time to time and I try to catch it when I can because Jon says it is way too small. I would try to go bigger if you can. Even a 320 to start would be good. Stock coyote pumps I think are that size."

I'm not sure who Jon is, but has anyone else heard anything about this? I tried to be as much research as possible about parts before buying/building, but haven't seen anything about this.

For background info I'm building a MkIV with a crate Gen II Coyote (no upgraded internal parts).

Any help/insight is greatly appreciated.

[FFinisher]

Hey gang,

I recently reached out to Lund Racing to get a custom tune for the Gen II Coyote I have installed in my roadster (getting closer and closer to finishing her up and getting her on the road). While giving the specs of the car, the fuel pump came up. I told the rep that my fuel pump is 190 lph. His reply was:

"The 190 lph is super tiny and less than what a stock coyote has. I would shoot for something like a 400 lph in size."

To which I questioned: "Will the smaller pump limit the tune?"

To which he finally replied: "The 190lph is probably too small for us to tune it at WOT. I've seen them come in time to time and I try to catch it when I can because Jon says it is way too small. I would try to go bigger if you can. Even a 320 to start would be good. Stock coyote pumps I think are that size."

I'm not sure who Jon is, but has anyone else heard anything about this? I tried to be as much research as possible about parts before buying/building, but haven't seen anything about this.

For background info I'm building a MkIV with a crate Gen II Coyote (no upgraded internal parts).

Any help/insight is greatly appreciated.

I have built many coyote cars. some with 255LPH and some with 190LPH, My tuner has never said anything about either. I believe the 190LPH should be just fine.

I know Mike Everson Just had a car tuned there and was very pleased. It was a coyote, I am not sure what it had for a fuel pump

[flip1216]

FF,

Thanks for the input. I have heard really good things about Lund, so I am pretty sure they know what they're doing. I just haven't heard anyone mention this before, so I wanted to be sure before I start buying new parts and redoing things.

[delta0014]

I have a Lund tune on my Gen 3 with a 255lph fuel pump. Had no problems.

[frd2]

Something else to keep in mind - if done correctly the data log will identify a fuel supply issue. My pump was large enough, but I used the provided fuel supply and return lines. They were restricting fuel at wot high rpm. I can tell the difference now that i ran larger lines.

Stock Gen 1 coyote.

Greg

[Hoooper]

190 is a very small pump, at 55 PSI and 12.5V it may barely support 400HP. Fuel pump flows are indicated at 0 PSI generally, so the 190 lph pump really only supports 150 lph or so at the Coyote's 55 PSI.

[rich grsc]

Who drives around at WOT? On a race car, yes would be relevant, not on a street driven car.

[FFinisher]

Who drives around at WOT? On a race car, yes would be relevant, not on a street driven car.

Ahhh…... the voice of reason.

[hogauto]

Just had mine tuned with a 255

[edwardb]

I've used Lund Racing for three Coyote tunes. Two Gen 2's and a Gen 3. All with 255 lph Walbro GSS340BX pumps. Zero issues with fuel delivery and they knew exactly what I had. For my recently completed Gen 3 Coupe with the Gen 3 Coyote, I did the WOT runs. Zero issues with fuel delivery. They said all the data looked perfect. So I'm just not sure where they're coming from. Maybe someone there has some bad information or they aren't clear about what you have. Jon is probably Jon Lund Jr. who I've worked with and seems to be very good and knows what he's doing.

To go a little deeper, it is true that pump mfg's rate their pumps at a certain PSI. Walbro, based on everything I've found, rates theirs at 40 psi. So for the Coyote which is 58 for the Gen 2 and 60+ for the Gen 3, the actual flow is going to be somewhat less than the rating number. In my case, looking at Walbro's published data, my 255 lph pump is still putting out 227 lph at 60 psi and 13.5 volts. https://walbrofuelpumps.com/media/wy...S340.chart.jpg. Using the 10 HP/gallon guideline, still plenty. If you look at the chart, pretty big difference between 12 volts and 13.5 volts. The Coyote alternator typically runs even a bit higher than that. So no issue IMO using the 13.5 volt rating. If your alternator fails and you're running on battery power, yes you'll have less fuel pressure available. But that's not your biggest problem at that point. Also BTW, I'm using 3/8-inch supply and return lines. That's based on Aeromotive recommendations. I know builds are done with the stock 5/16 and 1/4 inch lines. But those are maybe a little marginal.

All of the above could be repeated for the 190 lph pumps. The numbers would be slightly less but still OK for a stock Gen 2 Coyote. According to Mark at Breeze, a 190 lph pump is good for 470 HP at 13.5 volts and 58 psi. I'd recommend sticking with a 255 lph for the Gen 3.

[rich grsc]

I've used Lund Racing for three Coyote tunes. Two Gen 2's and a Gen 3. All with 255 lph Walbro GSS340BX pumps. Zero issues with fuel delivery and they knew exactly what I had. For my recently completed Gen 3 Coupe with the Gen 3 Coyote, I did the WOT runs. Zero issues with fuel delivery. They said all the data looked perfect. So I'm just not sure where they're coming from. Maybe someone there has some bad information or they aren't clear about what you have. Jon is probably Jon Lund Jr. who I've worked with and seems to be very good and knows what he's doing.

To go a little deeper, it is true that pump mfg's rate their pumps at a certain PSI. Walbro, based on everything I've found, rates theirs at 40 psi. So for the Coyote which is 58 for the Gen 2 and 60+ for the Gen 3, the actual flow is going to be somewhat less than the rating number. In my case, looking at Walbro's published data, my 255 lph pump is still putting out 227 lph at 60 psi and 13.5 volts. https://walbrofuelpumps.com/media/wy...S340.chart.jpg. Using the 10 HP/gallon guideline, still plenty. If you look at the chart, pretty big difference between 12 volts and 13.5 volts. The Coyote alternator typically runs even a bit higher than that. So no issue IMO using the 13.5 volt rating. If your alternator fails and you're running on battery power, yes you'll have less fuel pressure available. But that's not your biggest problem at that point. Also BTW, I'm using 3/8-inch supply and return lines. That's based on Aeromotive recommendations. I know builds are done with the stock 5/16 and 1/4 inch lines. But those are maybe a little marginal.

All of the above could be repeated for the 190 lph pumps. The numbers would be slightly less but still OK for a stock Gen 2 Coyote. According to Mark at Breeze, a 190 lph pump is good for 470 HP at 13.5 volts and 58 psi. I'd recommend sticking with a 255 lph for the Gen 3.

Gotta up sell them $$$$$$ pumps and hangers.

[lewma]

Hey gang,

I recently reached out to Lund Racing to get a custom tune for the Gen II Coyote I have installed in my roadster (getting closer and closer to finishing her up and getting her on the road). While giving the specs of the car, the fuel pump came up. I told the rep that my fuel pump is 190 lph. His reply was:

"The 190 lph is super tiny and less than what a stock coyote has. I would shoot for something like a 400 lph in size."

To which I questioned: "Will the smaller pump limit the tune?"

To which he finally replied: "The 190lph is probably too small for us to tune it at WOT. I've seen them come in time to time and I try to catch it when I can because Jon says it is way too small. I would try to go bigger if you can. Even a 320 to start would be good. Stock coyote pumps I think are that size."

I'm not sure who Jon is, but has anyone else heard anything about this? I tried to be as much research as possible about parts before buying/building, but haven't seen anything about this.

For background info I'm building a MkIV with a crate Gen II Coyote (no upgraded internal parts).

Any help/insight is greatly appreciated.

I got the exact same response from Lund. I replied that I wasn't planning on too much WOT driving ( if any really ). Their tune is working well on my Gen2 Coyote.

mark

[Railroad]

255 here, call Ford Performance.

[edwardb]

"The 190 lph is super tiny and less than what a stock coyote has. I would shoot for something like a 400 lph in size..."

I Googled "What is the rating of a stock Mustang Coyote fuel pump." Pretty definitive answer came right up: "In the car using the stock 13.5 volts and nominal 55-psi fuel pressure, and not having to work against supercharger boost, Kenne Bell figures the stock pump is good up to 281 liters per hour, or 753 rwhp." http://www.mustangandfords.com/how-t...pump-flow-test

Not sure that's 100% comparable since the Mustang OE setup is a returnless on-demand system that maybe needs faster response and cycling than the return style used in the crate motor. That's pure speculation on my part. But a thought.

Regardless, 400 lph in a stock Coyote? That's just silly.

[flip1216]

Thanks to everyone for the updated information. I think I am gonna see what the 190 will do (its already installed) and then upgrade to the 255 if I see any fuel issues. I agree that I won't be driving WOT all the time, but want to be sure I don't starve the engine when I actually want to go all out.

Thanks again for the help.

[MisterAdam]

I have built many coyote cars. some with 255LPH and some with 190LPH, My tuner has never said anything about either. I believe the 190LPH should be just fine.

I know Mike Everson Just had a car tuned there and was very pleased. It was a coyote, I am not sure what it had for a fuel pump

Mike does tunes??!!! I am just north of him and am debating on getting a tune.

[NAZ]

There's not much downside to running a bit more flow than required but there is a downside of being short and running lean under load and high cylinder pressure.

So you're going to build a high performance car with an engine making sufficient power to spin the tires and you're never going to mash that loud pedal? Right! If that's true, then why spend the $$ for that power plant?

Don't cheap out on the parts to support your build. Do the math and figure out what flow rate pump you need to support the HP capability of your engine not some imaginary partial throttle scenario you haven't a clue how much fuel is needed for.

[FFinisher]

No, Mike had a car tuned....


And... I miss spoke... he had a car tuned at MPE racing in Taunton, MA . it was not Lund.
Sorry for the error.

[GTBradley]

Thanks to everyone for the updated information. I think I am gonna see what the 190 will do (its already installed) and then upgrade to the 255 if I see any fuel issues. I agree that I won't be driving WOT all the time, but want to be sure I don't starve the engine when I actually want to go all out.

Thanks again for the help.

I did the Gen 2 Coyote with 190lph fuel pump from Breeze Auto and standard size fuel line. I had it professionally dyno-tuned and it put out 401 RWHP. Mike at Breeze says that this setup is good to 480 bhp with a safety margin.

My take on bigger than necessary fuel pumps is that it could cause a cavitation issue, as there will be a lot of fuel returning to the fuel tank.

[rich grsc]

I did the Gen 2 Coyote with 190lph fuel pump from Breeze Auto and standard size fuel line. I had it professionally dyno-tuned and it put out 401 RWHP. Mike at Breeze says that this setup is good to 480 bhp with a safety margin.

My take on bigger than necessary fuel pumps is that it could cause a cavitation issue, as there will be a lot of fuel returning to the fuel tank.

I used a 255lph pump with my 331, only because it was shipped as part of the intake package. It caused problems, when fuel in the tank dropped below 1/2 full, aeration of the fuel by the return caused a slight rolling surge when cruising. Air bubbles sent through the fuel lines was the problem. Had to change out the stock pump bracket fo one that had the return line near the bottom of the tank. All the extra fuel being pumped also can heat up.

[NAZ]

It should go without saying that a fuel system needs to be correctly designed & installed to function properly. And that includes sizing the pump flow rate to support the engine and fueling requirements, something that we shouldn’t need to guess about. There are many websites that will walk you through how to do this.


Cavitation and heating of the fuel from pumping friction could be a concern with some high flow/high pressure systems and indeed, some OEM diesel-powered vehicles have heat exchangers on their return fuel lines as diesels use high pressure pumps. Some use a variable pressure system which regulates the fuel pressure between 3,000 & 23,200 PSI. Remember, pumps create flow not pressure. Pressure is the resistance to flow and the more resistance the more friction. But gas powered EFI systems do not generally use high pressure pumps unless it’s a GDI system.


Now 255 liters per hour sounds like a lot. Most folks don’t work with these values so let’s convert them to a scale we might be more comfortable with – like gallons per minute. 255lph = 1.123 GPM. And the difference between 255lph and 190lph is 65lph or 0.286 GPM. Hardly what we might think of as high flow rates and the GPM delta between a 190lph and 255lph is just a tad over ¼ GPM. And the ~55 PSI pressure we supply this fuel at is hardly high pressure. So, don’t fret if your return style fuel system is a bit oversized, it’s not about to cause cavitation or over heat the fuel on it's own. It will simply return the fuel not needed by the engine when power demand is low. To provide some contrast, I run a pump that flows 784lph at zero head. The only downside is that it’s very noisy, but big pumps are.

[GTBradley]

The 255 is pretty well proven to work fine on the Gen 2 Coyote. The 400 that was mentioned in the original post and even the 320 is what concerns me. I don’t get why they would even suggest a pump like that.

[JohnK]

I know this video has made the rounds here before, but it's worth a look for those that haven't seen it. Pro-M does a nice job demonstrating how a return line that dumps fuel back into the top of the tank can cause aeration problems.

[rich grsc]

I know this video has made the rounds here before, but it's worth a look for those that haven't seen it. Pro-M does a nice job demonstrating how a return line that dumps fuel back into the top of the tank can cause aeration problems.

Thats the exact problem I had, and why I think this idea of slapping an oversized pump on a street drive car is stu-id.

[NAZ]

It's easy to mistake a design issue for a pump issue but as Pro-M has demonstrated in their video, the Mustang return system is a poor design that can create problems. Once the poor design is corrected they can run a much larger flow rate pump with no aeration issues.

Again, the takeaway is: a fuel system needs to be correctly designed & installed to function properly.

[Hoooper]

Thats the exact problem I had, and why I think this idea of slapping an oversized pump on a street drive car is stu-id.

There is no connection between those two issues. The 190lph is still capable of causing aeration issues 99% of the time if you are dumping fuel back into the top of the tank above the pump and blowing bubbles into the pump. The only time the 190 makes much of a difference in this case is when youre crossing 400+ hp and the 190 isnt returning any fuel to the tank because its not flowing enough to keep up with the demands of the motor.

[rich grsc]

There is no connection between those two issues. The 190lph is still capable of causing aeration issues 99% of the time if you are dumping fuel back into the top of the tank above the pump and blowing bubbles into the pump. The only time the 190 makes much of a difference in this case is when youre crossing 400+ hp and the 190 isnt returning any fuel to the tank because its not flowing enough to keep up with the demands of the motor.

Maybe you can't follow what I'm saying. There is a definite connection, over sized fuel pump WAS causing issues on my car, I KNOW because I had to take corrective action.

[JohnK]

Maybe you can't follow what I'm saying. There is a definite connection, over sized fuel pump WAS causing issues on my car, I KNOW because I had to take corrective action.

Rich, with all due respect I think you have the right solution attributed to the wrong root cause. Yes, a different pump hanger solved your problem. No, the problem was not an oversized pump, it was a poorly designed fuel hanger. As the Pro-M video shows any size pump can be run with their hanger without aerating the fuel. Conversely, any pump will aerate the fuel if dumped into the top of the tank.

[GTBradley]

Suffice it to say that the right design without overkill is the best solution, agreed?

[NAZ]

Some would call the glass half full and others would call it half empty. An engineer would say it's designed twice as big as necessary.

Spec the pump too small and you invite engine damage, spec it too large you spend too much $$. Best advice is to spec the pump with a bit of margin.

Think about this. The by-pass is running near full pump capacity at idle and low speed cruise. An engine like mine that is capable of putting out more than 1000 HP and needs a big pump to feed that. But at idle & low speed cruise it doesn't take any more fuel than the average warmed over street car. And still if the system is designed correctly there will be no issues with a big fuel pump.

I've designed several and always fall back on my hydraulic engineering training. My car's fuel system runs like a Swiss watch yet likely produces twice as much flow as most street cars. And at idle is dumping more fuel back to the tank than most street cars total flow capacity.

[nuhale]

I'm using the GM filter/regulator without return to tank. My 190lph will be perfectly fine with my un-modded gen2 coyote.

[rich grsc]

Rich, with all due respect I think you have the right solution attributed to the wrong root cause. Yes, a different pump hanger solved your problem. No, the problem was not an oversized pump, it was a poorly designed fuel hanger. As the Pro-M video shows any size pump can be run with their hanger without aerating the fuel. Conversely, any pump will aerate the fuel if dumped into the top of the tank.

With all due respect, stop telling me what I know about my car. I never had an aeration problem with the old pump, and the fuel WAS NOT DUMPED INTO THE TOP OF THE TANK, it was returned to the stock Ford return line on the hanger.. The problem started by returning more than 50% of the pump capacity.