fuel return

THE BULL · 12-13-2022, 09:08 AM

This answer might be a bit more technical than you can understand.

Depending on your goals will determine if so.

The main issue with return less systems is the size of the hose and folks attempts at solving fuel pressure issues.

The issue is not fuel pressure but fuel flow and the now lack of there of.

With the introducction of surge tanks we see that even return less systems dont lean out any more.

Without a pressurized chamber the oem feed line just dries out as it demands more flow however due to the size + lenght of this hose fuel pressure just bleeds off the regulator. Upon demand the regulator closes however since theres really barely any volume then a lean condition presents itself.

I did a recent test in my fuel injector cleaner machine. Upgrading the pump from a 150 lph to a 240lph and while I did see some pressure increase when I try to flow high flowing injectors the pressure drops tremendously.

Now If I add a plastic chamber in the middle of the pressurized line I dont get as low of a drop. If I could squeeze a bigger chamber there would be little to no pressure drop in that setup.

This transitions into real life scenarios.

Return style works in keeping fuel flowing through the system by having a regulator outside of the tank and keeping the rail with as much of a direct flow from pump to rail as possible. The problem with return style is that it too can be affected by flow.

What you see is folks blowing ridiculous money on dual/triple pumps because that's what everyone does and have been doing for years. Surge tanks only started trending because the looks of the system were finally understood by the regular population.

A simple surge tank can keep you at a single pump for some time. A dual pump with a surge tank will over kill most VHRs. (900-1000whp has been a safe limit for a while)

You usually see these types of issues with air as well.
Turbo single cylinders suffer from this flow as well, the turbo is just simply not able to create boost on command without enough exhaust flow. By adding a pressure chamber on the cold side you see a much smoother flow and no loss of pressures when you dont want them.

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12-13-2022, 09:08 AM	#5 (permalink)
THE BULL Base Member Join Date: Apr 2021 Location: Florida Posts: 216 Drives: G37S Rep Power: 26850	This answer might be a bit more technical than you can understand. Depending on your goals will determine if so. The main issue with return less systems is the size of the hose and folks attempts at solving fuel pressure issues. The issue is not fuel pressure but fuel flow and the now lack of there of. With the introducction of surge tanks we see that even return less systems dont lean out any more. Without a pressurized chamber the oem feed line just dries out as it demands more flow however due to the size + lenght of this hose fuel pressure just bleeds off the regulator. Upon demand the regulator closes however since theres really barely any volume then a lean condition presents itself. I did a recent test in my fuel injector cleaner machine. Upgrading the pump from a 150 lph to a 240lph and while I did see some pressure increase when I try to flow high flowing injectors the pressure drops tremendously. Now If I add a plastic chamber in the middle of the pressurized line I dont get as low of a drop. If I could squeeze a bigger chamber there would be little to no pressure drop in that setup. This transitions into real life scenarios. Return style works in keeping fuel flowing through the system by having a regulator outside of the tank and keeping the rail with as much of a direct flow from pump to rail as possible. The problem with return style is that it too can be affected by flow. What you see is folks blowing ridiculous money on dual/triple pumps because that's what everyone does and have been doing for years. Surge tanks only started trending because the looks of the system were finally understood by the regular population. A simple surge tank can keep you at a single pump for some time. A dual pump with a surge tank will over kill most VHRs. (900-1000whp has been a safe limit for a while) You usually see these types of issues with air as well. Turbo single cylinders suffer from this flow as well, the turbo is just simply not able to create boost on command without enough exhaust flow. By adding a pressure chamber on the cold side you see a much smoother flow and no loss of pressures when you dont want them.