I have an Aeromotive Phantom 340 system, which is basically their 340lph pump, return system - feeds rails then to regulator and the return, -6 (3/8) feed and return. No fuel heating issues or any issues of any kind. Pump is quiet as well. Easily feeds the 470hp engine.
The PWM is wholly unnecessary, its a "cost saving" idea at the OEMs. Even the corvette style one, you could change your fuel filter and the tolerance could jack with your fueling (bad parts out there).
You don't want to PWM just any fuel pump either.
So, In tank pump and return style is what I would recommend anytime.
Trying to understand this, so a low tech return system worked on your low HP ride with no noticeable issues, then you out think an entire industry in your spare time and gratuitously post your conclusions based on this one experience alone potentially misleading countless readers? Interesting extrapolation based on one result. Keep up the good work.
Wow, thanks for your really really nice reply. Of course, its not like the people who make the fuel pumps also agree with me or anything:
https://www.aeromotiveinc.com/tech-help/faqs/faq-340-stealth-fuel-pumps/(read line item #6). While they do say you can use a returnless system with a PWM, it's with some caution and doesn't work well with just any pump. Of course I may not have spoken properly and said returnless at the right time.
Funny thing is I work in the auto industry, and I also know what their motivations are. If they can get by with less plumbing, they will. Because the connections cause more assembly problems (cross thread, strip, leaks, more connections to be made during assembly, etc) than plugging in some modules. They are also making the car for one application, not the wildly varying applications that would be used on people's mild to wild modified cars.
The theory of a return system is a lot less complicated, fuel flows from the pump, into the rails, over the injectors, and then the regulator, controlled by a simple spring returns the unused fuel to the tank. Please tell me how this is a bad thing? Provided the pump can keep up with the fuel demands, you don't ever run out of fuel. No worry about hydraulic delay, and the pressure is controlled nearer to the injectors.
The corvette filter just uses a sized orifice to return fuel to the tank instead of a spring...and a small one at that. So if the size is off (low quality part), the pressure can change.
I'd be extremely shocked for anyone to have fuel heating problems with a return system and an in-tank pump. The OEMs also made systems exactly like this for years. Low-tech isn't always bad. I'm not misleading anyone. The higher the HP a modified car is, the more likely you are to see a return system regardless of what it came with. But hey, do what you want, I'd rather see someone run some extra line then spend a lot of money on something they may not be able to troubleshoot easily. The extra line and having a regulator in the engine bay is really the only downside of a return system.
