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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
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do i need an aju fpr

  • Thread starter Thread starter murphmaster5
  • Start date Start date Dec 25, 2005
M

murphmaster5

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Oct 2, 2005
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Dec 25, 2005
#1
  • Dec 25, 2005
  • #1
just wondering im in the works and want to know if i need an aju fpr,
306
typhoon upper and lower
255 fuel pump with 24lb injectors
E cam
gt40 alum
and if i dont need what kind should i get is there some that come with pre set psi, I realy dont know much about this thanks
 

RacEoHolic330

I like to dress like a pretty girl
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Mar 4, 2003
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Allentown, PA
Dec 25, 2005
#2
  • Dec 25, 2005
  • #2
it's nice to have one but you need a gauge as well to know what your fp is set at. I'd reccomend a Kirban ajfp gauge. Pretty much the best stock-style gauge made
 
M

murphmaster5

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Oct 2, 2005
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#3
  • Dec 25, 2005
  • #3
around what psi should i be looking at with my set up, Oh yea and the heads will be out of the box no porting same with intake
 

srothfuss

Last night I stabbed the same guy 7 times in a row
Oct 17, 2004
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Dec 25, 2005
#4
  • Dec 25, 2005
  • #4
The stock unit keeps the pressure around 38 - 39 PSI. If you get an adjustable one, set it at that....

Which leads me to my thought: Why replace a part on the engine with one that will do the same thing? I mean, if the OEM unit keeps the pressure where it needs to be, than what good is an aftermarket one that does the same thing?
 

RacEoHolic330

I like to dress like a pretty girl
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Mar 4, 2003
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Dec 25, 2005
#5
  • Dec 25, 2005
  • #5
srothfuss said:
The stock unit keeps the pressure around 38 - 39 PSI. If you get an adjustable one, set it at that....

Which leads me to my thought: Why replace a part on the engine with one that will do the same thing? I mean, if the OEM unit keeps the pressure where it needs to be, than what good is an aftermarket one that does the same thing?
Click to expand...


This is a topic that has been debated over and over. Some say they aren't necessary at all, but others say they are needed. I like having an ajfp regulator because it has helped me with getting my car to idle right.

It has to do with pulsewidth and atomization of fuel and a bunch of other stuff that is waay over my head. From what I read, it's more of a tuning band-aid to make smaller injectors seem bigger, but that really means that you need bigger injectors which will bring that fuel pressure back to stock. There are some pretty crazy threads on the corral about this topic.
 

srothfuss

Last night I stabbed the same guy 7 times in a row
Oct 17, 2004
1,796
3
0
Woodward Ave.
Dec 25, 2005
#6
  • Dec 25, 2005
  • #6
I see.... Maybe for boosted applications? Or High Horsepower needs.

I never venture outside of Stangnet so I really don't know.
 

Michael Yount

Mustang Master
Apr 10, 2002
9,039
6
79
Charlotte, NC
Dec 25, 2005
#7
  • Dec 25, 2005
  • #7
First - are you speed density or mass air?

If mass air - get a gauge first. If your stock fpr is holding pressure right around 38-39 psig at warm idle with the vacuum line off the regulator and plugged -- then no, you don't need an adjustable unit. If it's not -- get an adjustable and set it at the stock pressure as described above.

If you're speed density, you may find that you can do some tuning with fuel pressure -- but I don't think SD is gonna like your cam choice in any event. Also - messing with fuel pressure is about the only way to try and make the 24's work unless someone who knows what they're doing is gonna burn a chip for you. So if you're SD - the E cam and the 24# injectors present some real challenges...
 
L

luckythirteen13

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Jul 19, 2005
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Dec 25, 2005
#8
  • Dec 25, 2005
  • #8
its better to tune the car with pulse width then with fuel pressure. although if you are sc'd and dont have an fmu, ive heard its best to set fp to 50psi and then tune with pulse width
 

Bad92GT

The 5 Minute Plan Man
Jun 10, 2004
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Dec 25, 2005
#9
  • Dec 25, 2005
  • #9
i figure a new part can always help unless its so off key its just not right.. but i just put mine on today.. getting ready for the lower intake. But i figure it being new will help flow and its new and clean.. new gaskets and everything. Also having the ABILITY to adjust it is whats the point.. you may need it someday and if you dont have it.. you have to wait till you get one
 
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