fuel return

phunk

As far as I know, we might have been the first aftermarket company to integrate dampers to complete aftermarket fuel systems and directly into aftermarket rails. We have been doing it for over 10 years. When we started, the only thing on the market we had seen was a Marren damper, universal application part.

It wasn't without reason. We were having unidentified issues for some years without understanding why. Eventually we got it sorted out. Yes the fuel pressure pulsation is basically a pressure resonance of the fuel injectors closing. The pulsations can cause audible noise and have big side effects on the fuel injection system at resonant frequencies, occurring at particular windows of engine speed.

Soft rubber fuel lines have dampening qualities. We always used hardpipe and PTFE, which is why were had problems earlier on while everyone else was still using rubber core stainless braided hoses. I am sure some fuel injectors exacerbate the issue as well, if they have a more aggressive or harsh closing of their valve. Larger injectors probably contribute as well.

Does any decent fuel system have to have them? It certainly wont hurt to lower the amplitude of the pulsations with a damper or 2 or 3. If your car has a lot of soft fuel line, it may already have adequate inherent dampening. At this point, where fuel rails are being CNC machined per application lots of the time, its difficult to justify eliminating them. You might just bottom them out at high boost with big fuel pressure, but that wasnt really when pulsations were causing grief. Its more of a problem at steady engine speeds where you find and hold resonant frequencies that wreak havoc and cause drivability issues. In the years that we struggled with pulsation issues, we never saw a problem under meaningful power, it was always just an issue when cruising at steady engine speeds.

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