Throttle cutting out in hard left turns !!!

[Plimmer]

Track Day update:
I finally got a chance to test a few weeks ago at COTA, and unfortunately my mods improved things a little but my car still has terrible surge out of left hand turns. BUT THE GOOD NEWS IS AFTER DAVE'S INPUT AND OTHERS, I THINK I HAVE A SOLUTION THAT WILL ULTIMATELY WORK.

If you have a stock fuel pump hat follow my plan A, if you have a Fore or aftermarket twin pump or triple pump setup, follow my plan B.

Background:
My setup is as follows:
1. Twin pump aftermarket hat running return style fueling
2. Holley HydraMat on both pumps (did not help one bit)
3. Foam jammed into hump as tight and as many pieces I could get in there (doesn't work cuz I still struggled in lefties)
4. Old stock fuel pump zip tied to passenger side hat and running full time while on track (did not work but made surge recovery a little faster)
(the above does not work, so follow my plan A or B below)

COTA is anti clockwise track with a lot of left turns, and basically I discovered that left turns that you trail brake into are the WORST and sweeper lefts are ok. So basically braking into a left turn will highlight the problem faster than a simple left curve, But some guys also saying really long left turns also highlight the problem.

Plan A: (For cars with stock fuel hats and returnless style systems)
1. Zip tie a fuel pump at least as big as the stock pump or even bigger like a Walbro F90000267 to the passenger side sender unit. Wire it with an on/off switch so you can turn it off when not on track. Why such a huge pump? Because you need to move enough fuel back to the driver side within micro seconds, else you will surge.
2. Discharge this second pump directly into the stock fuel hat bucket. See the pictures I've attached to give you an idea how. I haven't tested this but I would zip tie the discharge end of the pump into the hat, not simply just into the drivers side. This is a key step to keeping drivers side hat full of fuel.
3. If you do 1. and 2. above you will have theoretically created an internal surge tank using the stock hat.
4. I would still jam as tightly as possible as many foam blocks as you can across the saddle hump.

Plan B: (For Twin and triple pump return style systems)
1. Buy an aftermarket surge tank, like Radium or similar. Mount your twin or triple pumps in the surge tank.
2. Reinstall your stock fuel hat into the stock drivers side location and follow steps 1 and 2 of plan A above.
3. Instead of discharging the passenger side pump into the stock hat as per plan A, you could discharge it into the surge tank, then you will have the stock pump and the passenger side pump both feeding the surge tank. Ya, this could be 4 or 5 friggen fuel pumps in the car, but thats what it takes to feed a boosted beast pulling more than 1g in turns....lol
4. Discharge the surge tank return into the stock fuel hat. I'm going to drill a hole by the black marks I made in the middle of the hat, so it helps keep the hat full. See very bottom picture.
5. For wiring, the surge tank pumps should be staged based on engine demand, have the stock driver side pump run all the time, and have the passenger pump staged or with an on/off switch.

Bottomline is your home track might be clockwise and not to big a problem, but if your home track is COTA like me, then you will have issues. I'm going to follow plan B, and will report back in August when I do my next event.

The pictures below are the stock hat separated and with the fuel pump removed, but you can see where it would normally sit. Use the pics to figure out how to zip tie the passenger discharge into the hat. The fuel pump and fuel filter normal sit inside that bucket. Or wait a few months for me to do it and I'll show you what I did.

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[boardkat]

not sure how i missed this when i was piecing my system together. fucking fore. what a cluster of a system for anything that isn't going in a straight line with a full tank. i found starve on 3/4 of tank on the first left-handed 3-2 decel when i was testing my new 700whp+ (low boost!) E85 dual-274 pump L4 setup. unbelievable that they can sell this system in good conscience.

anyway, i found a solution that fits my needs for now - lucky enough to have an innovative crew in my own backyard with a viable option. just put in a radium hat with bucket/check valve and pliable pump socks swapped in place of that horrendous open hat design fore uses.

avoiding foam on the hump until i find out at what fuel level and speeds/sustained g's i experience starve at. fingers crossed! at some point cutting the trunk floor out and putting in fuel cell with surge tank will be the right solution at any level but trying to avoid moving the CG higher and behind the axles.

keep the shiny side up out there!

 

[DickR]

For you guys adding multiple pumps, etc. why not simply convert to the GT350 pump, wiring, and controller, etc.?

 

[boardkat]

For you guys adding multiple pumps, etc. why not simply convert to the GT350 pump, wiring, and controller, etc.?

can’t meet fueling needs and isn’t a return-style system.

 

[JohnD]

The more stuff I do to my car the higher the cornering speeds go and the sooner it starts burping on a tank of gas.

 

[DickR]

can’t meet fueling needs and isn’t a return-style system.

What about for guys running NA engines close to stock who don't need more fuel but need to solve the long left corner problem?
See Dave's post on the differences between the GT and GT350 system . . . basically two pumps, etc. but otherwise identical. If I read it correctly the second pump results in more than enough left over capacity to keep the venturi transfer pump working.
https://www.mustang6g.com/forums/th...-in-hard-left-turns.14693/page-4#post-2193003

 

[o-man]

What about this stuff
https://www.holley.com/products/fuel_systems/hydramat/

 

[Plimmer]

My update:
I agree with a previous comment that the Fore and similar open hat designs are terrible. I had to top my tank to full for a session at Cota and then 8 laps later I was cutting for left turns. Got old fast.

So I went a similar route and installed a Radium surge tank in the trunk. So my setup is as follows:
Single pump in tank runs all the time with Key On, pumps to surge tank and excess returns back to main tank
Surge tank has typical twin pumps setup return style
I also have a pump in the passenger side, but don’t need it. Used it once when I ran out of gas on track, and then used it to pump fuel to driver side

With the surge tank I can run way below a quarter tank before issues start

Also I did try that Holley mat, and it helps a tiny amount, but won’t cure problem I had.

 

[DickR]

How do the various late model brand cama models deal with this or do they have the same issue?

 

[Shelby_Exotics]

WHAT DID YOU DO TO FIX THIS? I have a gt350 that I put Cortex Bushinga in front and rear and now she won’t complete any left turn without cutting out.? Thanks

I am experiencing the same thing immediately following hard left turns as well. I rewatched my track video from the weekend and it cuts when I start to straighten the wheel after almost any left. This does not happen during the first several laps, only later on in the session. I never had this issue before installing my fore return fuel system, so I think the fueling diagnosis might be accurate. [MENTION=20846]ddozier[/MENTION] can you explain your fuel tank foam trick a little more? I'm very interested in giving this a go[/QUO

Watch my speed just after the 1:29 mark. You will see right as I am about to hit the apex my speed starts to drop very quickly. That is when it started starving and I didn't return to full power until about the start/finish line.

lmao about the hood. I have the MMR mount that uses the head rest posts to attach. I had it mounted on the passengers side and had the seat tilted pretty far forward to even be able to see that much. ohhh crap as I am typing this I just realized I could have raised the seat..... doh. lol

The lap timer is "Harry's Lap Timer" it is an app you can download on android and apple devices. It is the pertolhead version and was only $20. As you get more serious you can add external sensors like a better GPS antenna and OBD II scanners that connect via bluetooth . I am going to pick up a vbox GPS which will be 20hz (20 locations per second) versus my phone only hitting about 1hz (one location per second). That will give me much more accurate speed and track mapping. The OBD II scanner can start picking up throttle/brake position, gear selected, etc...

Watch my speed just after the 1:29 mark. You will see right as I am about to hit the apex my speed starts to drop very quickly. That is when it started starving and I didn't return to full power until about the start/finish line.

lmao about the hood. I have the MMR mount that uses the head rest posts to attach. I had it mounted on the passengers side and had the seat tilted pretty far forward to even be able to see that much. ohhh crap as I am typing this I just realized I could have raised the seat..... doh. lol

The lap timer is "Harry's Lap Timer" it is an app you can download on android and apple devices. It is the pertolhead version and was only $20. As you get more serious you can add external sensors like a better GPS antenna and OBD II scanners that connect via bluetooth . I am going to pick up a vbox GPS which will be 20hz (20 locations per second) versus my phone only hitting about 1hz (one location per second). That will give me much more accurate speed and track mapping. The OBD II scanner can start picking up throttle/brake position, gear selected, etc...

 

[ddozier]

How do the various late model brand cama models deal with this or do they have the same issue?

This is a common issue on cars with "saddle bag" style fuel tanks. BMW, Camaro, Vetts, if you increase the lateral g-load beyond about 1.2G you will be able to slosh the fuel from the drivers side to the passenger side in high G left hand turns. There are a few bandaid fixes you can try but if you are going to keep increasing the lateral loads you will ultimately have to redesign the fuel system.

Bandaid fixes you can try:
1. keep the fuel level above 3/4 tank when on track
2. add a fuel safe foam to the hump of the fuel tank to try and reduce sloshing in left hand turns, buys you a little more corner speed but is difficult to install and can shift out of place and cause fuel gauge to be inaccurate.
3. add a secondary fuel pump on the passenger side to be used on track days to constantly move fuel from the passenger side into the OEM fuel hat (this is what the BMW guys do, there is a kit made for them that could used for inspiration for a kit on the mustangs, https://www.bimmerworld.com/Intake-Fuel/Fuel-Filters/E36-Fuel-Starvation-Kit.html
4 stay on street tires and drive slower, not an option for me.

More permanent fixes:
1. larger drop in OEM style fuel hat, not an open hat design but one like the Walbro TU2038HP, helped a little but still need at least a half a tank to limit starvation
2. add a surge tank to ensure the fuel hat is always wet with fuel
3. add a fuel cell and remove the OEM tanks
4. remove the Fuel Pressure Regulator in the OEM fuel hat, add a FPR at the fuel rail and run return fuel line to the passenger side of the fuel tank, add a secondary fuel pump to transfer fuel from the passenger side to the drivers side tank. using this setup will limit the chance of the secondary fuel pump running dry and failing. This is how most BMW race teams running with OEM tanks solve the problem. http://www.pumpkininc.com/content/doc/guide/ag-8.pdf

Dave

 

[Plimmer]

WHAT DID YOU DO TO FIX THIS? I have a gt350 that I put Cortex Bushinga in front and rear and now she won’t complete any left turn without cutting out.? Thanks

Don’t mess around (like I did). Just get a proper surge tank
http://www.radiumauto.com/MPFST-Multi-Pump-Fuel-Surge-Tank-P271.aspx

 

[PoppinJ]

Just chiming in that this is an issue on the 2018 GTs as well, although it doesn't seem to be as extreem as what I've seen described. It's hard to tell though as there is really only 1 turn at my local track that causes any issues. When it does, it's just a split second blip of total power loss, nothing protracted.
I know the 18 has a slightly different fuel system with both port and direct injection, but if I'm not mistaken uses the same pump just a higher static pressure of 65 psi in the lines. Not sure if having more fuel in the lines and twice the injectors gives a little more leeway or not, but it certainly doesn't solve it completely.

 

[GJarrett]

Subscribed. I had this exact same problem at AMP at the exact same turn that others here have described, beginning to occur at about 3/8 tank. I'll look into the Radium surge tank but the link presently states they are out of stock and don't list a price. @Plimmer what did yours cost and how easy was the install?

 

[Plimmer]

Subscribed. I had this exact same problem at AMP at the exact same turn that others here have described, beginning to occur at about 3/8 tank. I'll look into the Radium surge tank but the link presently states they are out of stock and don't list a price. @Plimmer what did yours cost and how easy was the install?

Unfortunately it’s not cheap. The surge tank was about $500, and then you’ll end up spending quite a bit on AN fittings. If you’re pretty technical you can try keep it as simple as possible, I’m not familiar with the ecoboost fuel pump, but basically I have a pump in the OEM tank that runs on Key On and circulates to the surge tank. Then the surge tank has a pump wired up to the factory power supply. My setup is a return style system, but it might be possible to run returnless.

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