Fuel starvation problem solved

[VictorH]

This is not an every track problem. But at Barber Motorsports Park after coming off the museum turn, turn 9 the track then bends left into a moderately fast left-hand sweeper. Last time I was at Barber in 2023, I would consistently have engine cut-out going into this corner if the tank level was 1/2 or less. Hugely annoying as its not good for the motor as it will go lean and basically it means you have to tank up after EVERY session.
I had known thqt KPM was working on a solution (I didn't care about their 1,000+ HP capacity pumps) and that their fix had a dedicated pump working the saddle tank to keep the fuel canister full in all conditions. Installed this last Fall but didn't get to test it until this past weekend. Can confirm it's a 100% fix. It's not inexpensive, but it does work. Ran tank to just below 1/4 and it never stuttered or hesitated at the corner once.

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[John S]

I'm trying to understand how a higher capacity pump on a naturally asperated engine that doesn't require such an expensive upgrade solves the problem? Isn't this a tank baffling/fuel pick-up problem? Would a GT350 system with a pump in each saddle tank be any better? Just trying to better understand the root issue and best way to prevent fuel starvation, I haven't tracked my car yet and I sure don't want to find out what happens if I lean out and shut down in the middle of a high RPM sweeping turn. (I'm running E85 so just keeping the tanks above half-full is not very practical.)

 

[VictorH]

I don't know if the exact reason(s) are explained here but there's a plenty long thread about this problem.

https://www.mustang6g.com/forums/threads/fuel-starvation-on-track.184328/

 

[NightmareMoon]

The left side tank is fed by a venturi effect suction off the one pump on the normal GT. Basically it sucks a little from the passenger side tank into the hat. It also feeds extra pressure into the hat from the driver side.

I think if you put a much larger pump in there, the venturi effect is also stronger, which helps with the starvation because there's a stronger feed into the hat when you need it.

And if your pump is weak, it may draw less from the passenger side, which is a problem I think I've been having.

 

[shogun32]

you don't need the 1000hp, the 800hp is fine.
https://kpmfuelsystems.com/product/kpm-800hp-in-tank-fuel-module-s550-mustang-gt-2015-23-2/

@KPM Fuel Systems I thought you guys had a 'stock' setup (500-600hp) for like 500-$600 price point. Did that get discontinued?

The issue is the Ford venturi design is inadequate. KPM apparently didn't sleep thru venturi class at engineering school.

 

[NightmareMoon]

you don't need the 1000hp, the 800hp is fine.
https://kpmfuelsystems.com/product/kpm-800hp-in-tank-fuel-module-s550-mustang-gt-2015-23-2/

@KPM Fuel Systems I thought you guys had a 'stock' setup (500-600hp) for like 500-$600 price point. Did that get discontinued?

The issue is the Ford venturi design is inadequate. KPM apparently didn't sleep thru venturi class at engineering school.

Well for E85 in the future I may want the 1000, and the extra draw should help feed the bucket in high G situations. Anyway I’ll post an update when its in and we’ve adjusted the tune for it.

 

[2morrow]

you don't need the 1000hp, the 800hp is fine.
https://kpmfuelsystems.com/product/kpm-800hp-in-tank-fuel-module-s550-mustang-gt-2015-23-2/

@KPM Fuel Systems I thought you guys had a 'stock' setup (500-600hp) for like 500-$600 price point. Did that get discontinued?

The issue is the Ford venturi design is inadequate. KPM apparently didn't sleep thru venturi class at engineering school.

This is great, thank you.

I often have the same issue as OP coming out of the carousel into turn 7 at Sonoma and the north side of Thunderhill in the fast sweepers.

 

[2morrow]

This is not an every track problem. But at Barber Motorsports Park after coming off the museum turn, turn 9 the track then bends left into a moderately fast left-hand sweeper. Last time I was at Barber in 2023, I would consistently have engine cut-out going into this corner if the tank level was 1/2 or less. Hugely annoying as its not good for the motor as it will go lean and basically it means you have to tank up after EVERY session.
I had known thqt KPM was working on a solution (I didn't care about their 1,000+ HP capacity pumps) and that their fix had a dedicated pump working the saddle tank to keep the fuel canister full in all conditions. Installed this last Fall but didn't get to test it until this past weekend. Can confirm it's a 100% fix. It's not inexpensive, but it does work. Ran tank to just below 1/4 and it never stuttered or hesitated at the corner once.

How is your experience with the new pump?

 

[VictorH]

Pump has been great. Complete fix to the problem. Required no tune, no adjustment to fuel pressure or anything else. I ordered the 1000HP pump as that was the smallest one at the time. I understand there's an 800HP pump available now which was not available when I ordered mine.
It's a complete fix to the problem, I have run my tank, on track to well below 1/4 tank with absolutely no issues. Did not intend to run it that low as I started well above 1/2 tank but the car is certainly capable of burning some gas when pushed.

Only advice, as this is a simple DYI project. When you go to change the pump; 1) buy a fuel pump "opener" tool (well worth it as it's really tight); 2) Run the gas tank down as low as you dare to without running out of fuel. Much less messy and less gas to deal with with doing the exchange.

 

[KPM Fuel Systems]

That's great to hear that the pump sorted out the surging. We now offer the KPM800 module for an even more economical fix for the surging at the track! And all of our fuel pump modules are fully upgradeable. This means that even though your starting off with the 800 and thinking that you won't be further modifying the car down the track but then one day it happens(as we all get the itch) we can supply the upgrade components and then you rebuild your module accordingly, or add on extra pumps and fuel lines!

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