To FPD or not to FPD

Trexthe3rd · 10-12-04, 10:29 PM

I know many of you have eliminated the FPD but the debate continues as to the need of the FPD. Since I am currently in the process of doing my fuel system and I believe that the FPD is necessary for high pressure and flow applications (above 50psi going to 850,1600), I'm going to use http://www.injector.com/fueldampers.php

Just wondering if anyone else have used aftermarket FDPs and which one they used.

DaleClark · 10-12-04, 10:46 PM

Yeah, it's a tough call. I've eliminated pulsation dampeners on TurboII's in the past with a banjo bolt with no ill effects, but there's still that nagging in the back of my head that Mazda wouldn't have put it there for no reason whatsoever. That, and the 787B Lemans car actually had a pulsation dampener on the fuel rail - there's gotta be something to it!

That's cool that Marren is making an aftermarket one, though.

Dale

JaNusSolSumnus · 10-12-04, 11:04 PM

Wow, at first I thought there was no alternative, just the downward spiral of replacing the OEM one over and over again...

I didnt know anyone had eliminated it -- I thought of trying but was worried of the ill-effects.

I'll have to keep an eye on this thread for when the 'masters' get involved with some tid-bits of info.

EDIT: The Marren one looks a bit more resiliant compared to the stocker as well as costing the same.. I may invest in this little guy.

~Kris

Barban · 10-13-04, 01:56 AM

how do you know when it has gone bad?

Nameless · 10-13-04, 02:15 AM

You can smell it in your engine bay... if you have a bad sense of smell I'm sure you can also tell when your engine bay is on fire.

JONSKI · 10-13-04, 10:01 AM

I changed mine at 100k miles. Considering what I spend on fluids, maintenance and GAS, $100 is worth the piece of mind.

Mahjik · 10-13-04, 10:05 AM

Trexthe3rd,

Are you upgrading your fuel system or just over-hauling the stock system?

If you are upgrading, some FPR's like the SX unit have dampening capabilities built in.

neit_jnf · 10-13-04, 10:34 AM

whats the fpd for anyways?

DamonB · 10-13-04, 10:36 AM

Quote:

Originally Posted by neit_jnf

whats the fpd for anyways?

Fuel Pulsation Dampener

It helps maintain the fuel pressure in the rails at a constant rate while the injectors constantly open and shut. If you understand hydraulics it essentially functions as an accumulator.

I'm a firm believer in never eliminating something if I'm not absolutely and completely sure. I say leave the FPD in and replace it every 5 years or so to be safe. Many aftermarket FPR's also have this built in as mahjik said.

dubulup · 10-13-04, 10:40 AM

Eliminated it...Aeromotive

BOTTLEFED · 10-13-04, 10:59 AM

I eliminated mine with no problems. But I have since went to a SX fpr, so as far as long term use without it, I cannot say... I only had it that way for a few months.
If you are upgrading your fuel syst. then get an adjustable fpr and then you don't need your stock fpd.

neit_jnf · 10-13-04, 02:57 PM

ohhh, I should have just thought more about the name! haha it dampens the pulsations created by the pump to ensure a better flow out the injectors! hahaha it's been a long time since engineering school

Quote:

Originally Posted by DamonB

Fuel Pulsation Dampener

It helps maintain the fuel pressure in the rails at a constant rate while the injectors constantly open and shut. If you understand hydraulics it essentially functions as an accumulator.

I'm a firm believer in never eliminating something if I'm not absolutely and completely sure. I say leave the FPD in and replace it every 5 years or so to be safe. Many aftermarket FPR's also have this built in as mahjik said.

alberto_mg · 10-13-04, 04:12 PM

don't know if this thing would work with an FD, but check out this aftermarket FPD
http://www.injector.com/fueldampers.php

GoRacer · 10-13-04, 04:18 PM

I wanted to eliminate mine and change to SS lines but when I was ready to order the replacement peice, K2RD went offline. Can someone ask them to work weekends or something?

Trexthe3rd · 10-13-04, 04:19 PM

Quote:

Originally Posted by alberto_mg

don't know if this thing would work with an FD, but check out this aftermarket FPD
http://www.injector.com/fueldampers.php

Nice job buddy, check the first post in the thread ^^^^.

Trexthe3rd · 10-13-04, 04:31 PM

Quote:

Originally Posted by Mahjik

Trexthe3rd,

Are you upgrading your fuel system or just over-hauling the stock system?

If you are upgrading, some FPR's like the SX unit have dampening capabilities built in.

I am upgrading the entire fuel system and using the Aeromotive FPR (the one pictured in dubulup's post). The only thing I'm concerned with is this, the FPR has to be situated on the return side of the fuel system to work(after the fuel rails), while for the FPD to work it has to be before the fuel reaches the injectors. So how would the FPR compensate for the pulsation (after market or other wise) if it is installed where it has to be?
Technically I can not see how the FPR can act like a FPD. I know there are aftermarket fuel rails with FPD built in (for Hondas etc.), didn't find one for the FD. But the operating principle is the same, the damping is done prior to reaching the injectors in conjunction to the FPR after the injectors.
Personally I'd rather be safe than having to regret not putting in a 150 dollar part.
By the way, the FPD I found is easily rebuildable so no more worries.

Zyon13B · 10-13-04, 04:46 PM

Quote:

Originally Posted by dubulup

Eliminated it...Aeromotive

So your saying the Aeromotive has FPD capabilities built in. That would be cool because I have that FPR. And I will remove the FPD then.

alberto_mg · 10-13-04, 10:11 PM

Quote:

Originally Posted by Trexthe3rd

Nice job buddy, check the first post in the thread ^^^^.

DOH! I was on there for a different reason and remembered this thread.

RotaSpinna69 · 10-13-04, 10:32 PM

I'd like to learn more about this for the future...lets keep this going

Trexthe3rd · 10-14-04, 03:44 PM

I'm curious to hear from someone else who has studied fluid systems. I took a semester of tranport theory and based on the ss flow equations, I just don't see how ANY FPR can act as a FPD being downstream of the fuel rails.
In low pressure and low flow system (such as stock) it wouldn't be a major concern, but with almost 5000cc of fuel at 50-60 psi of pressure, pulsation can be deadly under wot conditions.

Trexthe3rd · 10-16-04, 09:50 PM

Just got the new FPD in, will be going through the fuel system upgrade (already installed the new Nippon Denso fuel pump). Will keep a picture log of the process for anyone interested. The picture shows the approximate location of the FPD to the primary rail.

Trexthe3rd · 10-16-04, 11:09 PM

Here's what the new setup should look like when finished.

JaNusSolSumnus · 10-17-04, 10:03 PM

What parts would I need tro order just to use the Marren FPD in place of my stock unit?

I worry of nothing more than I do an engine fire so any alternative that is safe over the stock unit but wont effect my fuel delivery system is a + in my book. I'm gonna redo my vac lines next weekend so I planned to either order the stock replacement and hope for luck or to get the Marren unit.

Thanks,
~Kris

Trexthe3rd · 10-17-04, 10:55 PM

The Marren FPD has a 3/8 NPT input. What you'll need to make it work with the stock system is somewhat involved. To start with, you will need to tap the primary fuel rail with 1/4 NPT tap. From there you will need a 1/4 NPT to 6AN elbow and a 6AN tee. You will also need a 3/8 NPT to 6AN adaptor to the FPD. The last thing is a 6AN barbed hose end to mate with the stock fuel lines.

JaNusSolSumnus · 10-17-04, 11:11 PM

Ahh Jesus--- I may as well just get the stock FPD and sleep well until I can afford to upgrade my entire fuel system.

I'd consider a new FPD from Mazda safe for say another 60k right?

Thanks for the quick answer, I'd love to see how your setup turns out when complete.

~Kris