Fuel Starvation
 

Hi guys! recently ive had someone ask to make something specific for this issue. But i was wondering if anyone else has experience fuel starvation. Who have already done the fuel flap addon but still have issues. I anyways read from fb groups of people adding a scavenge pump in the other side of the tank. But i always get questions on what would be the best way to control it. So im making a device that connects to the factory G meter and turn it on based on the Gforce going on in the car.

But in reality im just wondering how many of you are doing that type of system?

Most folks use a manual switch and let the secondary pump run dry under starve conditions; it's a relatively cheap replacement.

I wouldn't try to reinvent the wheel. Radium has several products out there to handle the issue:
http://www.radiumauto.com/Fuel-Pump-...Z86-P2108.aspx

http://www.radiumauto.com/FST-R-Fuel...-FPR-P348.aspx

I have a radium surge tank mounted in my trunk and have run the tank completely dry on track. I didn't experience any hint of fuel starve until just a few turns before I completely ran out of fuel. I had a small bobble on corner exit that felt weird, then BAM completely out of gas 3 straights later. had to get a tow truck to pull me in. (at least I took the checker before I ran out of gas. ;) )

yikes! seems like once you get a good air pocket in the fuel line it can cause your car to do that haha. ;) like you said good thing it was at the end lol. fuel pump hanger seems like a easier solution than then full surge tank.

yeah i assumed that would of been a simpler and more common solution haha. I guess i like making PCBs so when someone has a suggestion my brain tells me its easily doable.

well that's kinda the point of the surge tank and a return style system. the factory in-tank pump feeds the surge tank with low pressure fuel. there's a return on top of the surge tank that dumps back in top of the factory pump so it purges any air from the surge tank.

THEN the surge tank itself has the high pressure pump in it that feeds the engine. the engine itself is still a return type, so any air would quickly be purged from that line too. don't know where the return line from the engine goes, but it does go somewhere in the system. (the whole thing was installed in the car when I bought it and it works well, so I haven't bothered nit-picking the routing ;) ).

The issue with the radium setup is it is not practical for the average track day goer to mount a surge tank in the trunk and it is expensive.

I think what the average guy is looking for is a way to automatically switch on a scavenge pump. Some guys run them on manual switch but they burn out the pump running it at full power the whole time. I think the next step after that is to run it on a small DC motor controller to adjust pump output, you shouldn't need to run the scavenge pump at full duty cycle. Then come up with an auto switching setup. I have a couple ideas in mind but don't have the time to mess with it right now. All in I think I am at 100 bucks for a second fuel basket with pump and sender, a motor controller, and some misc items to the project.

yeah thats why for me to would be easy to use the stock accelerometer in the ABS unit and measure Gforce like that. its easy to know when your taking a hard left turn and just send a signal to a relay to turn it on.

I know the PCB is a rough draft lol

https://www.geraldjustprojects.com/w...6.52.09-PM.png

Far more sophisticated then what I was looking at building.

Gerald.. sell an easy plug and play solution with a pump and comprehensive install instructions and you’ll be a big hit.

Enjoy your early retirement.

Understood there. Based on that point, it may be more advantageous to look at the in-tank solution with a better jet pump and whatnot inside it which scavenges better than the factory setup.

This would reduce/eliminate the start/stop electronics and it just becomes a passive hydraulic solution which still fits in the tank without extra hassles and electronics and parts to fail.
I'm a very big fan of K.I.S.S, and my free time is such that I'd rather just buy a proven solution than to fiddle with something and invent it myself. But hey, that's my preference. I'm certainly not saying someone else shouldn't develop their own solution if they have the time and desire, just that there is already a solution out there that does the job and is known quality. :)

I don't think an intank solution with a better jet pump is going to do it. My understanding of a jet pump has been the fuel flow from the electric fuel pump creates suction to pull fuel through the other side. So if the fuel pump is starved, there isn't anything to create suction. It wouldn't be too hard to test as you can buy a jet pump from radium for like 50 bucks. May be worth giving a try. I could also be totally wrong on my understanding of a jet pump, it's happened before.

I wonder if it wouldn't be cured by simply moving the pickup closer to the outside corner, or making it flexible like those on chainsaws and such.

You are correct in some of that.. the factory setup includes a small swirl/surge can and the pump is submerged inside that with roughly 1qt total volume (including that displaced by the pump and the plastic bits). The factory stuff feeds into there so the pump doesn't just become exposed and run out of fuel in every turn. How long does it take to drain the sump and all that? I don't know the answer there. but the jet pump thing basically works to help keep the swirl tank full. it's ALSO fed from the left side of the tank so it's not just the little jet pump thing from the right side.

I have a stock pump assy sitting on my workbench if you want photos, but it'll have to be tomorrow since I have some plans today and tonight.