Fuel Pressure Regulators???? how to choose

[xkuntrycowboyx]

Grady~ "Tell the pcm the truth about airflow & fuel
as opposed to
1) The cheat method after-market maf makers have devised
2) Mechanical adjustment of fuel pressure"

whats the cheat method after market maf makers use??? plz explain if u can.

 

[final5-0]

Grady, you said you knew this was helping but were trying to get ppl in here... well it actually was helping, its lettin us learn from ea. other and thanks... also thanks to everyone else... anyones thoughts, unless completely retarded help, i was thinkin about one, but im just trying to learn as much as poss. soo keep going, im seeing it from both views, and tryin to make sense of it.

here was a thought... say you have MIL elim's on ur 02's, then the comp isn't reading them anyways right? so is it in open where it would make a diff with the AFPR?
just a thought

My understanding about the MIL thing is ...... 96 and newer is where they come into play ...... they are not needed for our cars.

Its got something to do with that ORB stuff or whatever it is called .............
All I know is ...... they ain't for EEC IV

Grady

 

[final5-0]

Grady~ "Tell the pcm the truth about airflow & fuel
as opposed to
1) The cheat method after-market maf makers have devised
2) Mechanical adjustment of fuel pressure"

whats the cheat method after market maf makers use??? plz explain if u can.

Typed out all that stuff before

Nobody had anything to say about it before

but I knew it

I knew it would be only ...... just a matter of time before someone would ask about this stuff again

Here are my thoughts as well as those of others

http://forums.stangnet.com/showthread.php?t=597535

Remember ... you asked for it

This will keep you busy for a while
but
the data you need to learn about this subject is all together in one easy place and you don't have to search all around the net to find it

You newer guys have it so easy now a days compared to when I was trying to figure out all this kind of stuff

It just ain't fair

Grady

 

[1slow95]

I still don't have an AFPR, and I'm debating if I should even get one...I've heard most places say to set the pressure to 40psi before going for a dyno tune, so why bother with an AFPR if Im just gonna keep it at the stock setting? Seems like an unnecessary waste of ~$100 to me....

 

[xkuntrycowboyx]

Just read a post about LONGTUBES... and needing a AFPR in that case...

The gains will not be off the chart on a stock motor but it should net about 10HP. Shorties would be a tad less. Long tubes shine later down the road with other mods. The install is a pain but shorties aren't that easy on our cars either. You will need an adjustable fuel regulator because the O2 sensors will be down stream on the header causing the computer to add more fuel. You will need to turn the fuel pressure down a bit. Another item needed is O2 extenders ($35 at Steeda, Pro-M, Brothers Performance, etc.).

 

[Davin]

You will need an adjustable fuel regulator because the O2 sensors will be down stream on the header causing the computer to add more fuel. You will need to turn the fuel pressure down a bit.

crapola

Are you kidding me? So with all the crap people do with removing cats etc, the computer's supposed to think more fuel is needed b/c the O2 sensors are a little further down the line? What is supposed to have changed to the gas composition in that 16"? I can't think that makes a big difference and I would think if the CPU determined that fuel pressure is insufficient, it would up-regulate to increase according to the O2 sensor feedback...Tell me if I'm wrong...

 

[Zero Signal]

Yeah I don't think I agree there either.

But as far as the adaptive strategy goes, I also have logged changes to the KAMRF's over time after messing with things, like the MAF. When you go to open loop at WOT, the adaptive consistently locks onto some KAMRF values. If the computer doesn't use adaptive for WOT, then those values would be 1.000 in OL. So I still don't get what the AFPR will do unless, like Grady mentioned, you max out your adaptive. But if you get to the point where you really need to overide the adaptive, and it does happen, you really should be doing it directly through the computer.

Anyway, that's my real input for this thread

 

[final5-0]

crapola

I can't think that makes a big difference and I would think if the CPU determined that fuel pressure is insufficient, it would up-regulate to increase according to the O2 sensor feedback...Tell me if I'm wrong...

I have found no evidence that supports the pcm has the ability to determine fuel pressure.

Grady

 

[Zero Signal]

Yeah we have no fuel pressure sensors anyway, so there is literally no way for the computer to know what it is. Hell, there isn't even a vacuum sensor, so it couldn't even equate or reference it via vac/fuel pressure function or anything.