Why use an Adjustable Fuel Regulator?

vristang

15 Year Member

Mar 31, 2005

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#1

• Apr 3, 2006

• #1

I had a thought and figured I would get some input from others.

Is there any need to use and adjustable fuel pressure regulator when tuning with a tweecer?
If you are supoosed to return fuel press to the stock level, why not use the stock regulator?

thanks for the input
jason

 

final5-0

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Apr 6, 2003

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#2

• Apr 3, 2006

• #2

vristang said:

I had a thought and figured I would get some input from others.

Is there any need to use and adjustable fuel pressure regulator when tuning with a tweecer?
If you are supoosed to return fuel press to the stock level, why not use the stock regulator?

thanks for the input
jason

Click to expand...

I do use the stocker

I have never owned an afpr myself

Guess I never will

Grady

 

nmcgrawj

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#3

• Apr 5, 2006

• #3

Well cant higher pressures make the injectors act "bigger" than what they really are at a given pulsewidth?

 

Don 95Vert

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#4

• Apr 5, 2006

• #4

What he said...

 

Black95GTS

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#5

• Apr 5, 2006

• #5

nmcgrawj said:

Well cant higher pressures make the injectors act "bigger" than what they really are at a given pulsewidth?

Click to expand...

Yes, but you are over-driving them. Instead of running them harder then designed, a lot of peeps would rather get a bigger injector and run stock fuel pressure.

There is a right way and a wrong way to do things... a lot of guys do HCI and use 24's with an AFPR, while IMO they should be getting 30s and hammering out a tune. But then I am an admitted TwEECer junky and would rather tinker with the eec then slap a mechanical band aid in there.

Adam

 

nmcgrawj

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#6

• Apr 5, 2006

• #6

Well yea i hear ya. Regardless of if u or i would rather tune with our pms or tweecer, that is what they are made for right?

 

final5-0

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#7

• Apr 5, 2006

• #7

nmcgrawj said:

Well cant higher pressures make the injectors act "bigger" than what they really are at a given pulsewidth?

Click to expand...

You are absolutely correct Nate

Allow me to ramble on for a while if you please and I promise ...... it will make a point about several methods of tuning ...... I hope

Lets consider three examples

1) Ford tunes our Stangs with the pcm ...... nuff said

2) Us hot rodders think we are tuning when we do stuff like:

a) Adjust the throttle body blade stop screw
b) Twist the dizzy
c) + or - fuel pressure
d) Use maf/inj's that are caled to each other

3) EEC Tuner/Tweecer peeps try and tune as Ford did but attempt to use values that more accurately represent what has changed due to the new hot rod parts that have been installed.

#1 has to be the most accurate ... would you not agree

#2 gets the job done ... has its limits & not much flexability

#3 can be effective ... WHY to change values must be known

When tuning with #3, you are striving for accuracy with things like a, b, & d from above.

Say you got everything all set and your tune is great

If you do any one or more of the below

Up the fuel pressure
Turn the tb screw
Twist the dizzy
Delete emissions equip
Install matching caled maf/inj's

The pcm now can't understand what happened

Any mechanical changes are counter productive to your previous tuning efforts

It is worth noting here the same kind of deal goes on when you make these kinds of mechanical adjustments on a stock Stang. The pcm can only deal with so much of that kind of stuff before it freaks and drivability goes out the window

I'm done now

Grady

 

final5-0

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#8

• Apr 5, 2006

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Don 95Vert said:

What he said...

Click to expand...

Good to see you over here

Don is a much better splainer than me

besides

He has forgot more than I know

Grady

 

Don 95Vert

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#9

• Apr 5, 2006

• #9

Thanks Grady. IMHO, raising FP is a temporary band-aid until you can get bigger injectors. If you are running out of injector just a little, one thing to keep in mind is that Ford rates their injectors at 39.5 FP, while the rest of the industry rates them at 43.5 FP. So if you are running 50# SD injectors at Ford Spec, they are NOT delivering 50# - so often in these cases raising FP to the mfg's specs can solve a problem where you are barely running out of injector.

 

cobramanphil

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Apr 5, 2006

#10

• Apr 5, 2006

• #10

I'd say get the afpr only if you know your stock one is shot or leaking pressure. Just make sure the aftermarket one has lots of BLING and is set at the stock fuel pressure

 

Z

zZsKyZz

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#11

• Apr 7, 2006

• #11

Hehe...

Twist the dizzy...

Hehe..

 

Don 95Vert

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Apr 7, 2006

#12

• Apr 7, 2006

• #12

Sometimes with a high pressure 255 FP, the stock FP cannot control fuel satisfactorily - in those cases an aftermarket FPR of good quality, may help. I'd always use an aftermarket FPR with a 255 HP FP.

 

WhiteDevil

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Apr 14, 2006

#13

• Apr 14, 2006

• #13

I used to use my AFPR to bump the pressure when i was using 19#ers. Now i just have it set to 39psi and i leave it there.

 

HPLouis

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Apr 18, 2006

#14

• Apr 18, 2006

• #14

I had to use an AFPR to bump down my FP after I added the inline and intank 255lph pumps. Plus, it gives me an additional port to stick an electric FP gauge on.

 

vristang

15 Year Member

Mar 31, 2005

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Apr 19, 2006

#15

• Apr 19, 2006

• #15

I never came back to say thanks for all the input.
Thank you.

So, if using a 255lph it may be necessary to use an aftermarket fpr, due to control issues.
I can understand that.

Guess I'll keep my afpr in place for the time being. I have enough things to worry about, just learning the tweecer.
No need to complicate things with concern about fuel control.

:Word:

jason

 

5.0_GT_kid

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Apr 20, 2006

#16

• Apr 20, 2006

• #16

I need to get a Tweecer so I can come in here and play with the big boys!