Fuel starvation on track

[ChipG]

I'm interested in trying Scoot's solution. My thought is to try a pump with roughly half the flow rate of the stock pump (maybe a stock 6cyl pump - FR3Z9H307B - less than $200), hang it on the passenger side, and power it with a switch that I'd only turn on for a track session. Thoughts?

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[VictorH]

Neither of those technically solves the "problem" just improves the symptoms. The radium hat and the KPM both provide a small amount of fuel storage around the pumps. Whether or not that's enough at applicable flow rates when navigating a left turn is probably dependent on how LONG of a turn and how tight of a turn it is.

The root of the problem is the IRS and the split tank setup. Not only does that mean you now have to balance the sides (or move fuel from the passenger side over the driver's side) it also means that there's limited ability to do things like sumps and rear exit fuel setups (which inline pumps and pickups).

At the end of the day, between hydramat, enclosed fuel buckets, better syphon jets, etc, it will HELP the issue, but the root is still there.

I was very close to solving this problem completely using low pressure lift pumps from the passenger side. And it does solve the issue by actively pumping passenger side fuel INTO my Radium bucket. I have yet to achieve a solution where it's automated. I wired in a switch to turn the pumps on and off, which is better, but not perfect. I bought the Autometer fuel guage (which allegedly has trigger capability based on custom fuel level targets) however, after multiple calls with Autometer, I can't get it to function as advertised. So now I simply have it as a second fuel guage so I can see how much fuel is in the passenger side. With the OE signal disconnected, I can also view how much is in the driver's side and when the driver's side is getting low(er) I can turn the pumps on and fill it back up.

Deatschwerks claims they've ran their micro lift pumps for an hour naked without burning them up, but I'm reluctant to try that (and simply wire the pumps to run constantly) in fear of them running dry when total fuel levels are 1/2 tank and lower (they'd push all the fuel to the driver's side). THat would automate everything, but then I'd stress about whether the pumps are unnecessarily creating heat or risking failure.

In the end, it's not THAT big of an inconvenience to simply fire them when I want more fuel over to the primary bucket and for a track application it's probably even more tolerable, but ultimately I haven't been able to get it to where I want it, which is no starvation issues (ever under any conditions) and no manual or unautomated features.

Totally agree with your points. It shouldn't be that complicated. My prior car was an E90 M3 which has a saddle fuel tank set up under the back seat just like the Mustang. I don't know the complete inner workings, but I think there was a pump on the driver's side to move fuel to the passenger side as the main pump was on the passenger side. I had to replace my fuel pump once and it was a integrated fuel pump, fuel filter and fuel sender all housed inside of bucket which I suppose was like a little surge tank. Was really effective, never had fuel starvation even when run down well below 1/4 tank.

 

[Angrey]

I'm interested in trying Scoot's solution. My thought is to try a pump with roughly half the flow rate of the stock pump (maybe a stock 6cyl pump - FR3Z9H307B - less than $200), hang it on the passenger side, and power it with a switch that I'd only turn on for a track session. Thoughts?

I didn't want to add the additional current draw, so I went with low pressure lift pumps. They flow well but don't draw a lot of current.

The DW Micro flows 210 liters per hour at free flow and only draws 3.5 amps. I wired up a pair of them which is about half the current draw of TI274 and flows about 420 liters/hour (which I repurposed the siphon line so it flows directly into my radium bucket).

There are other low pressure lift pumps on the market for cheap. The micro is $60/pump so a pair plus the T fitting and tubing and adapter to tie into the siphon hose can all be done for well under $200. Draws 7 amps total. I had to modify the OE passenger side pickup tube with a dremel to get the pumps (and filter socks) to the bottom of the tank. Used a couple of band clamps and a DW style bulkhead fitting drilled through the top cover. Cheap switch that I wired and mounted in the back wall of the center console (with a light on signal). Works great, just wish I could have gotten the autometer guage to function properly, then they would run constantly if they're wet and only kick off at low fuel.

 

[ChipG]

I didn't want to add the additional current draw, so I went with low pressure lift pumps. They flow well but don't draw a lot of current.

The DW Micro flows 210 liters per hour at free flow and only draws 3.5 amps. I wired up a pair of them which is about half the current draw of TI274 and flows about 420 liters/hour (which I repurposed the siphon line so it flows directly into my radium bucket).

There are other low pressure lift pumps on the market for cheap. The micro is $60/pump so a pair plus the T fitting and tubing and adapter to tie into the siphon hose can all be done for well under $200. Draws 7 amps total. I had to modify the OE passenger side pickup tube with a dremel to get the pumps (and filter socks) to the bottom of the tank. Used a couple of band clamps and a DW style bulkhead fitting drilled through the top cover. Cheap switch that I wired and mounted in the back wall of the center console (with a light on signal). Works great, just wish I could have gotten the autometer guage to function properly, then they would run constantly if they're wet and only kick off at low fuel.

Good info, thanks. Is there a reason you think you need 420lph vs just 210lph? I've not been able to find the flow rate in the OEM pump, but with a quick look at fuel pump sizing it would seem that 210lph should support stock power. Are you FI or just wanting extra rate to be sure to keep fuel in the radium bucket?

 

[RagmopInKona]

Yes, normal. Start with a full tank each time.

It should not be normal. Not in a car designed to be tracked.
This should be an issue that pops up at 1/8 tank or less and not before.
Not in a vehicle sold to be tracked.
O/P might be time to install a real road course fuel cell that you can run down to a gallon of fuel and still not get the hiccups.

 

[Angrey]

Good info, thanks. Is there a reason you think you need 420lph vs just 210lph? I've not been able to find the flow rate in the OEM pump, but with a quick look at fuel pump sizing it would seem that 210lph should support stock power. Are you FI or just wanting extra rate to be sure to keep fuel in the radium bucket?

I'm boosted (pretty heavily) and I also wanted the additional flow to quickly transfer fuel over to the driver's side and not have it take a long time. 210/hour would probably be sufficient for OE power levels when you factor in the small amount of storage in the bucket.

 

[ChipG]

I'm boosted (pretty heavily) and I also wanted the additional flow to quickly transfer fuel over to the driver's side and not have it take a long time. 210/hour would probably be sufficient for OE power levels when you factor in the small amount of storage in the bucket.

I've ordered a pump and when I get it will start playing with the plumbing, etc. A detail question for you - you mentioned plumbing directly into the siphon line. I assume you did it in such a way that, with the transfer pump off, the siphon line still operates as intended. In other words, you likely plumbed into the side of the siphon line leaving the end open. Is that a correct assumption?

 

[JAJ]

This thread is amazing. It's strange to watch a bunch of Mustang GT and GT350 owners talking about how to fix a fuel starvation problem in the GT350, without realizing that the GT350 comes from the factory with twin fuel pumps (like the 2013/14 GT500 and the 2020+GT500). Unless you run it really low, it doesn't have a fuel starvation problem to solve.

Of course, as we've read in the thread, the GT350 twin pump system can exhibit starvation for a few drivers in a few situations on a small number of tracks, where it's not quite good enough. But, my fellow enthusiasts, there's a simple solution: Even the OP said that if he ran a full tank at the start of a session, he was okay, so START EVERY SESSION WITH FULL FUEL ON THOSE TRACKS THAT NEED IT.

 

[ChipG]

Unless I misunderstand, both of the dual pumps are in the same module and hanger in the driver side, leading to the issue being discussed, which is getting fuel out of the passenger side over to the fuel pumps. The fact that it's dual pumps isn't particularly relevant. As you noted I stated in the first post, yes, I can just fill up and run full before every single session, but that's a pain in the ass, along with being extra weight, and wouldn't help in longer sessions. The car absolutely does have a fuel starvation issue in track use, as several have attested, and I'm not sure why it seems to twist you up that I'd rather address it than fill up five times a day.

 

[Angrey]

Unless I misunderstand, both of the dual pumps are in the same module and hanger in the driver side, leading to the issue being discussed, which is getting fuel out of the passenger side over to the fuel pumps. The fact that it's dual pumps isn't particularly relevant. As you noted I stated in the first post, yes, I can just fill up and run full before every single session, but that's a pain in the ass, along with being extra weight, and wouldn't help in longer sessions. The car absolutely does have a fuel starvation issue in track use, as several have attested, and I'm not sure why it seems to twist you up that I'd rather address it than fill up five times a day.

It's not just a problem for the GT350, when I initially spoke with Aeromotive, they have been battling this with cars with saddle tanks/IRS for some time.

 

[JAJ]

Unless I misunderstand, both of the dual pumps are in the same module and hanger in the driver side, leading to the issue being discussed, which is getting fuel out of the passenger side over to the fuel pumps. The fact that it's dual pumps isn't particularly relevant. As you noted I stated in the first post, yes, I can just fill up and run full before every single session, but that's a pain in the ass, along with being extra weight, and wouldn't help in longer sessions. The car absolutely does have a fuel starvation issue in track use, as several have attested, and I'm not sure why it seems to twist you up that I'd rather address it than fill up five times a day.

And you're totally convinced that FP is so stupid that they'd put two pumps in one module without bothering to put the second pump pickup on the other side of the hump.

 

[JAJ]

BTW - back in the day when I had an E92 M3, BMW put one pump in the tank, but they ran a pump output over the hump to the other side. Sounds weird, but the fuel in that line was run past what amounted to a venturi fitting with a second line that actually pulled fluid back from the "offside" of the tank into a sump that the main pump pulled fuel from. Basically, one pump did the job of two, and the coffee-can style sump under the main pump kept the engine running during otherwise challenging hi-g turns.

 

[ChipG]

And you're totally convinced that FP is so stupid that they'd put two pumps in one module without bothering to put the second pump pickup on the other side of the hump.

Given the behavior I'm experiencing, I have no trouble at all believing they're that stupid. What has been said in this thread is that the tube from the passenger side is a low volume siphon, with several options for how to remedy that for those of us for whom it becomes a problem. You're the first one I've heard claim it's a direct pickup from the second pump. I've not yet opened mine up (though I will in the next couple of days) so can't say I am "totally convinced" of anything yet, just going on information from others who have. Have you found in your car that the second pump has a direct (not siphon) pickup from the passenger side or do you have a diagram/schema from Ford showing that? I haven't seen one but would love an accurate diagram if available.

 

[ChipG]

Well, the transfer pump is installed. I used a single 210lph pump and a separate hose routed directly into the main fuel pump bucket. I have a switch mounted on the dash near the interior temp sensor to turn it on. I'm running Nashville Superspeedway this weekend, and if I get some good dry weather should find out how effective this is addressing the fuel starvation issues I have there.

 

[Egparson202]

Well, the transfer pump is installed. I used a single 210lph pump and a separate hose routed directly into the main fuel pump bucket. I have a switch mounted on the dash near the interior temp sensor to turn it on. I'm running Nashville Superspeedway this weekend, and if I get some good dry weather should find out how effective this is addressing the fuel starvation issues I have there.

Good luck! Your approach seems solid.

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