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Originally Posted by travislambert
There are fuel level sensors on both sides of the tank that are independently accessible on the CAN network. My logs show what each fuel level sensor is reading.
The fuel pressure loss doesn't happen in the corners. It happens well after the car is level and no longer under a lateral G load. This combined with the fact that one of the sensors will be maxed out in the empty position (2.55v) until the next turn is pretty good evidence there is no meaningful amount of fuel available in a particular side of the tank.
Yes, I'm very confident because I've spent countless hours researching this problem with my laptop riding shotgun on the road course. Trust me, effectively all of the fuel transfers. In addition to the sensor data, when I had the DSX tuning pump, it was tapped at the bottom near the rear of the rightside tank where the fuel would certainly migrate to under acceleration. A hard right turn followed by a long straight would run the pump dry every time if there was less than 1/2 tank of fuel.
The G load effect on the fuel pickup isn't the problem that needs solved. With even the small factory pickups, at least one or the other will be submerged until the car is effectively out of fuel (under any G load the car is capable of). The problem is how to meet a fuel demand while fuel is only in one side of the saddle tank.
Planning for short bursts at WOT isn't ideal because there are some very long straights on road courses. VIR has one that is 3/4 mile, and there is a straight on the Nurburgring that is 1.3 miles+. A good solution is not going to leverage an assumption that WOT will only come in short bursts. An OEM quality solution is one that can sustain a sufficient fuel supply indefinitely while fuel is only present in one side of the tank. If a solution under this scenario relies on one pump, then we're basically right back at the original problem. If we had a single pump available that could pull this off, we could just swap the factory pump and leave everything else.
It's a tough problem. If it were easy the aftermarket would have it right by now, but they don't. The aftermarket providers like DSX Tuning, Fore Innovations, etc. all think they have the problem solved too... until it's tested on a road course.
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Thanks for all that info, that all makes sense and answers many of my questions. Based on that it sounds like we need a better solution, I'm not planning any upgrades I just enjoy learning about this and brainstorming solutions.
I dont agree there isn't a great aftermarket solution: a real fuel cell (e.g. Radium, Fuelsafe) with a Fuel Cell Surge Tank (Ti 285 lift pump, dual Ti 285 FST pumps), would solve all fuel tank supply issues up to the engine bay (pre HP pump, cam and injectors, etc). The price of a FC and FCST is not THAT much more than one of these inadequate in tank kits from Fore.
The cell has foam that stabilizes fuel movement, and you can install a big cell sized Hydramat on the lift pump if you want to go really far. And if you sell the car you can easily remove and install in your new car.