Like the title says. What is the point of these on an RX7? The many cars I've made fuel systems for (a few skylines, and a vw) none of these had a FPD. Why is it so important on an FD?

Reason I ask, is because I am doing a primary/secondary aftermarket system that has no FPR and was told to "MAKE SURE your fuel pressure regulator has a built in FPD!" This is majorly limiting the options I have for a quality FPR. I have a certain one in mind that I've used on past systems and was very happy with it, but alas... no FPD. I know the aeromotive has one, but personally I'm not a fan of their products (we won't get into that). Do I really need one? I would like more than just a YES/NO answer. Please explain the reasoning behind it... I like to understand everything I work on rather than just slapping it on because someone said so.


Discuss.

 

its not really a requirement to have an FPD, unless you have a close to stock FD really.... most get rid of it, as its a fire hazard and has a high potential to fail if its the original stock part

 

well, i guess i'll give this a shot...personally i think that its probably because of the somewhat violent nature of the rotary while its running, the pulsation damper might allow for more efficient fuel delivery under the more extreme conditions?

 

yes, I know... hence why the stock one is going.

what I'm asking is, with my custom fuel system... why must I have a FPD in the FPR?




What even doesn't make more sense, is the fact that when stock... the FPD is at the beginning of the fuel system, but if you have one in the FPR it's after the rails. What good would this do anyways? Don't you want to "dampen" the fuel BEFORE it goes through the rails?




And to the other answer... yes that is what I was thinking, but what gets me is the fact that the RB26 runs a lot "rougher'' that the rotary, but it doesn't have one?

The rotary is actually very smooth compared to most engines which is why I don't get why it needs a FPD.

 

A damper gives you more stable rail pressure. The reason it is unstable to begin with is from injectors opening and closing.

Nothing wrong with the stock damper, like every car part it has a predictable service life. They're about as reliable as any other 15 year old fuel system part.

 

It's like a shock absorber. As long as it sits somewhere between the pressure source and the pressure regulator it should work well. I'd also imagine that it should be as close to the rails as possible within the overall system.

 

I know what is does, but why is it on an RX7 and not other high powered sports cars?

 

Can anyone point out some other FPRs with a damper in them if yo uknow of some?

 

Because some engineer decided it was a good idea. There are many other cars that have them, seems like you're basing your assumption on incomplete info.

 

Oh, I'm sure other cars have them... it's just that I personally haven't come across on yet. We had a GTR make over 600whp without one, so I'm just questioning if it's really needed.

Basically it comes down to the fact that I don't really want to run an Aeromotive FPR... which is so far the only one I've found with a built in FPD.

 

They explain how to determine whether you need one or not here:

http://www.injector.com/fueldampers.php

Couldn't you add a T-fitting somewhere and put a damper like the one above on there?

I would try a search in the single turbo section. I'm sure it's been discussed there.

 

alot of fuel pump modules have the damper integrated into it. with all the bs people do to our cars it amazes me that people are trying to get rid of a useful fuel system component. it will help smooth out the injector pressure and afrs, never a bad idea. caddies had it in the tank as an inline unit. if you replaced the pump and forgot the damper the fuel rail would have an audible thumping sound.

 

ok... so possibly the cars I've worked on had it on the pump? that would explain why I didn't see one in the rail system.

If I were to run one of those other "inline" ones, should I put it before or after the rails.

 

Several of the aftermarket FPR's have dampers built in as well.

 

I've heard the Aeromotive has an integrated FPD, but regardless, I've never noticed a problem since junking the stocker

 

FWIW, Banzai has a simple FPD delete "how-to" on their site and claims that there are no ill-effects to removing it. http://www.banzai-racing.com/
But then that was the stock system.

 

It is about as necessary as the AST that some people still swear by Many have ran these cars for years without the FPD with no problem. I have known of 3 cars I have personally seen burned due to this failure and seen at least 6 customer cars over the last year have a leaking FPD. I havent seen any engines blow up due to the lack of one

However, like mentioned above, most aftermarket FPRs have them built in.

 

I understand what you mean by this... but if you're going to compare it to the AST it is only fair to mention that when people "eliminate" their AST they create what is basically a "mini/pseudo AST" at the filler neck by adding the S4 cap and nipple extension. The AST serves a purpose, but is unnecessarily complicated IMO.

I kind of understand eliminating the FPD on a stock car, since a new replacement is expensive and the risk of fire may be greater than the risk of leaning out a stock FD due to a possible pressure fluctuation.

On the other hand, I opted to just replace my own during the rebuild knowing that somewhere in Japan some guy did the math and he decided that the pulse dampener was necesssary at some operating condition.

 

My car won't have stock rails though, so is it still OK to not run one? I have an HKS FPR here that I want to use, since I've had good experiences with it, but to my knowledge it doesn't have a FPD.

This is it. If need be I can pick up an inline, it's just a lot of money for something that is not really needed (as some say).

http://www.titanmotorsports.com/hksa...hannelid=FROOG

 

How many times do you need your question answered? just take it out

 

lol, will do.