95 gt fuel press reg and injector question

1bad95 · Sep 18, 2009

With the mods listed in my sig, would it benefit me at all if i was to put in a 190 or 255lph pump and an adjustable fuel pressure reg? someone told me that with just the bolt ons currently on that i have the stock pump and injectors about maxed and that i would put in a bigger pump and an adjustable regulater to hold over until i needed injectors. im gettin a fp gauge and the autometer fitting for the rail now and was thinking about this also. I also plan on doing a upper and lower intake at least this winter too.

thanks fellas

i also posted this in the 5.0 section, but wanted to see if it would get more response here

2slo95fiveoh · Sep 18, 2009

you don't have anything in your sig....

1bad95 · Sep 19, 2009

Darn they were there, idk where they went. got it fixed again

BLACKPLAGE · Sep 19, 2009

the 19# will support up to 500hp @ 100% but not very well and probably wont get them to do that without a tune. however what you have there is well within the operating range of the 19's, if you are planning on future mods then upgrade to a 24#. as far as the pumps go the stocker is about 80 ish lph and will be fine for now unless you just want to spend the money for the bigger pump. the adj regulator is definitely beneficial. even in stock form the 5.0 will make more power with a little more timing and fuel. get a gauge and monitor the fuel pressure when you make changes.

Paul · Sep 19, 2009

BLACKPLAGE said:
the 19# will support up to 500hp @ 100% but not very well

No they won't. Not even close.

You don't really have any significant power mods. You'll be fine with your stock pump and injectors for now, and stock regulator too for that matter. In fact, I have adjustable regulators on all my cars - wanna know what pressure I set the cars at??? Stock. Once you get heads/cam/intake - then you can get some bigger injectors.

Paul.

MikeF · Sep 21, 2009

yes a adjustable reg will help you get better flow out of your stock inj.the 19lbs inj. is rated at 39psi if you increase pressure you will increase flow.thats how it works on my 42inj.thats how they tuned these cars for years.fuel pressure and timing.jmo

BLACKPLAGE · Sep 26, 2009

Paul said:
BLACKPLAGE said:

the 19# will support up to 500hp @ 100% but not very well

Click to expand...

No they won't. Not even close.

Well evedently you havent read the ford hi perf fuel injection book

You don't really have any significant power mods. You'll be fine with your stock pump and injectors for now, and stock regulator too for that matter. In fact, I have adjustable regulators on all my cars - wanna know what pressure I set the cars at??? Stock. Once you get heads/cam/intake - then you can get some bigger injectors.

Paul.

Paul · Sep 26, 2009

You read it in a book, so it must be true. Do a google search on Brake Specific Fuel Curve and you can find some good information on fuel injector sizing for a given horsepower.

LAFENATU · Sep 27, 2009

BLACKPLAGE said:
the 19# will support up to 500hp @ 100% but not very well and probably wont get them to do that without a tune.

wat?

N/A Numbers..

14 Lb/Hr 228 28.56 Gray
19 Lb/Hr 310 38.76 Orange
24 Lb/Hr 391 48.96 Lt Blue
30 Lb/Hr 490 61.19 Red
36 Lb/Hr 587 73.44 Dk Blue
42 Lb/Hr 685 85.68 Lt Green
60 Lb/Hr 800 100

NXcoupe · Sep 27, 2009

LAFENATU said:
BLACKPLAGE said:

the 19# will support up to 500hp @ 100% but not very well and probably wont get them to do that without a tune.

Click to expand...

wat?

N/A Numbers..

14 Lb/Hr 228 28.56 Gray
19 Lb/Hr 310 38.76 Orange
24 Lb/Hr 391 48.96 Lt Blue
30 Lb/Hr 490 61.19 Red
36 Lb/Hr 587 73.44 Dk Blue
42 Lb/Hr 685 85.68 Lt Green
60 Lb/Hr 800 100

The second number is hp correct? Is the third number the hp/injector? Or what?

BLACKPLAGE · Sep 27, 2009

Paul said:
You read it in a book, so it must be true. Do a google search on Brake Specific Fuel Curve and you can find some good information on fuel injector sizing for a given horsepower.

no reason for sarcasism, all i said was you havent read the FORD HI-PO FUEL INJECTION BOOK just because you dont believe it doesnt mean its not true. that number came from ford so evedently they dont know what they are talking about with THEIR stuff.

might as well lock this one too. something tell me its gonna get ugly in here.

Paul · Sep 27, 2009

Dude, it's not sarcasm. If 19 pound injectors support 500 horsepower, why did Ford put 24s on Cobras when they only make 240 hp? Why do 390 hp '03 Cobras use 42s? And Lightnings? And GT500s. None of them use 19s either.

I'm telling you that it is, unequivocally, flat out 100% wrong. Period. This is not internet mythology. This is simple and widely accepted facts, supports by science.

The calculation is (oversimplified) is desired horsepower x brake specific fuel curve divided by the number of injectors at .80 duty cycle = injector size in lbs/hr.

If you feel so strongly about it, back it up with more than "I read it in a book." and give us the science behind it.

Paul.

Steven · Sep 27, 2009

I'm with Paul on this one. Rule of thumb is usually just your general HCI car is cutting it close to the duty cycle of the 19lb injectors. I would not run an injector at 100%, thats just bad information.

toyman · Sep 27, 2009

Sorry, but 500 hp isn't supported by the math.

HP= (Nc x injector x dc)/ bsfc where:

HP = Horse Power
Nc = Number of cylinders
dc = Duty Cycle ( Injectors are engineered to operate at 80% dc but can be pushed to 100% for brief periods) Note that at 100% dc the injectors are always open.
bsfc = Brake specific fuel consumption (fuel efficency of the engine)This factor is about .50 lbs fuel per hour/horsepower for most high performance engines.

So, the math is.

HP = (8 x 19 x 1)/.5 = 304. Even if we can squeeze a a bit more fuel and use a bsfc of .46 the hp increases to only 330.

The 19 lb injectors at the engineered dc of 80% will comfortably support 243.2 HP.

BLACKPLAGE · Sep 28, 2009

BLACKPLAGE said:
the 19# will support up to 500hp @ 100% but not very well and probably wont get them to do that without a tune. however what you have there is well within the operating range of the 19's,

OBVIOUSLY yall dont read ENGLISH here it is again

Paul · Sep 28, 2009

Does quoting wrong information somehow change how wrong it is?

The first half of your sentence is wrong. The second half is right.

NXcoupe · Sep 30, 2009

Excuse me for interupting this argument, but can someone please address my question above all this?^ Those fuel injection books aren't written by Ford, they are written by an author that didn't get his facts straight evidently.