I have read a lot of threads and there are some that say that you do and some that say you don't need a pulsation damper. I'm custom making new fuel rails and lines and wondered if I absolutely needed to have a pulsation damper?

Thanks to all that help.

J

 

There are two schools of thought.

Pro PD= Fluid dynamics engineering says that they are required. You can have rail harmonics that can lead to a overly lean or overly rich situation at specific RPMs. Going lean at the wrong time could blow your motor. In addition without a PD, the soft lines and injectors take a much worse beating and may be subject to pre-mature failure.

Con PD = Some owners say they have been running thier cars without one with no problems that they are aware of. Often they claim the lack of a possibility of a leak outweighs the possibilty of problems outlined above.

So you will personally need to decide which one you want to go with. Without a engineering degree inf fluid dynamics and countless dyno time and access to modern test equipment, it is impossible to say which is right.

I personally believe that they are required on all fuel injected systems.

 

Ok, thanks Icemark. Does anyone have pics of an aftermarket PD built into their custom fuel set up?

J

 

The fuel pulsation dampener was/is a major cause of car fires in the '86-'88 rx-7. So the '89 and later rx-7 got a much more reliable fuel pulsation dampener. From what I read you can cram one into an '86-'88 but it's tight. My local mechanic replaced my leaking FPD for $350 (probably not with a more reliable one).

At http://www.mazdatrix.com/c-pulsation.htm you can get a more replacement for $150.

 

I ran my old modified Turbo II without a PD for 2 years with no ill effects. Current owner still runs it that way and has seen no problems with it. I originally replaced a leaky PD on that Turbo II with a NEW one from Mazdatrix. The new one started leaking after 8 months! NO JOKE! It was banjo bolt time after that..... I wasen't about to spend another $135 on a "NEW" pulsation dampener.

 

I remove my PD's as a first priority well 2nd priority. (oil cooler lines get changed 1st)

I have never had any noticable issues without it and like Icemark said to some of us whatever ill effect it may have sure outways losing your cat in a fire.

 

Take a look at this topic from the Archives: https://www.rx7club.com/forum/showthread.php?t=395021

 

My car burned... And I took it off. Now that I got a new swap (13b-re) I'm gonna get an aftermarket one.

 

Your car burned after you took it off? Your FC was destined to light up like a match.

 

Hmm, fire or no fire! I would go with no fire! Mazda put it there for a reason. I replaced mine about 2 week's ago with no bad effects. Piece of mind= priceless.

 

RETed, my question now is for you. The parallel set up posted on your site, it does not show a PD, and I understand that it may not be needed, but for peace of mind, I would like to have one. Where in your parallel set up would the aftermarket PD go? Or in your opinion (Only RETed's) is it needed?

J

 

i know someone told me how to reroute the pd to somewhere safer than the top of the engine(mike harrington from nc i think) but that sounds like a good idea. if you can reroute your oil filter in the bay, shouldnt be too hard for the pd

 

I was under the impression that the parallel mod removes the need for the PD entirely.

 

as I recall teds dual set up, uses two FPR. FPR will also work as PDs.

 

my take is ditch the thing unless you have a fat wallet.

 

Removing the PD IMO and most seasoned tuners is ignorance especially with the valued information on the net from manufacturers. if it was not for a reason don’t you think it would not be on the car?

Teds setup with that brand FPR has a built in PD but not very good one IMO. Has been known to fail.

I run a PD on each rail with a FPR. Only way for me. As you go to larger injectors you get more resence in the rail causing lean spikes. This is caused from the injector solenoid firing rapidly. Think of this as slaping your hand against the watter in the tub.