Fuel System Damper, why not? Options

[yarin]

I couldn't find that much info on here.... Pelican lists a damper in the FI system.

http://www.pelicanparts.com/914/Parts/Fuel...system1_big.htm

Which years and which systems include this? Why leave it out?

I'm building a MS system, do i need a damper in the system? Thanks

[lapuwali]

QUOTE (wwhalenc @ Feb 6 2006, 04:04 PM)

So it's just helping maintain a stable pressure behind the injectors...so there's not a pressure drop for a long duration/high volume injector squirt? I guess that'd be somewhat consistent with TimT's statement

Honestly, I think it's there only to prevent the odd resonant noise the system makes. Most EFI systems get away w/o a damper and are otherwise very similar to D-Jet in operation, esp. wrt possible pulsations in the fuel system caused by the injectors operating. Remember that D-Jet was the very first production EFI system available, so they were still learning how to make it all work. The 914 version of the D-Jet doesn't have the damper. The two L-Jet systems I've worked on didn't have one, either.

The damper was also up by the fuel pump in the nose of the car, not back by the fuel rails, and with all of the rubber lines involved in the Type 3 injection system, I'd say they would provide as much damping as you'd need for reducing any pulses in the fuel lines caused by the injectors.

Note, btw, that the noise goes away by the time the injectors are running. It's only there while the injectors are NOT running and the pump is operating. It's just as likely it's some characteristic of the pump.

MAYBE if you're running EFI with lots and lots of hard line running fuel, you'd see some benefit from such a damper. On a 914 with a stock or near stock system, it's clearly not needed.