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  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

need for aftermarket fuel injectors?

  • Thread starter Thread starter snake109
  • Start date Start date Dec 2, 2004

snake109

New Member
Dec 2, 2004
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Austin TX
Dec 2, 2004
#1
  • Dec 2, 2004
  • #1
Hey everyone, Im new to the site. I was wondering when upgrading your fuel injectors is a good idea? I dont see a supercharger any time in the future, but Im planning on x-pipes, headers, various intake bolt-ons ect... And what is the stock injector rating for the 00-04 4.6L?
 
B

billyfe390

New Member
Aug 18, 2003
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0
Dec 2, 2004
#2
  • Dec 2, 2004
  • #2
snake109 said:
Hey everyone, Im new to the site. I was wondering when upgrading your fuel injectors is a good idea? I dont see a supercharger any time in the future, but Im planning on x-pipes, headers, various intake bolt-ons ect... And what is the stock injector rating for the 00-04 4.6L?
Click to expand...

Stockers are 19lbs/hr and they will be sufficient until you start getting into P&P heads and cams. I think they are running at 90%+ duty cycle when you start reaching the 350bhp range.
 

Mr GT 02

New Member
Apr 8, 2004
548
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0
Peabody, MA
Dec 2, 2004
#3
  • Dec 2, 2004
  • #3
I also wonder if AFTERMARKET injectors are worth it, when u have bolt on mods equipped...

I was at the track one day and someone mentioned that I should get some injectors....I never asked him why I should tho....

Is there any increase of power or suttin with aftermarket injectors????? If I did get injectors ...could u get a bigger size??? 24lbs???? or is that only nessesary with blown stangs?????

WTF is up??
 

Stangsgrl

Member
Mar 13, 2004
132
1
18
Mesa, AZ
Dec 2, 2004
#4
  • Dec 2, 2004
  • #4
I was wondering the same when i turbo it down the road.... just waitin for the feedback
 

snake109

New Member
Dec 2, 2004
60
1
0
Austin TX
Dec 2, 2004
#5
  • Dec 2, 2004
  • #5
I found a formula for determining the required injector rating:
("Estimated HP" x "BSFC*") / ("# of injectors x .8) = "Injector flow rate"
* a typical BSFC is .4 to .6, .5 is a good number to start if you dont know.
I dont know if the HP is flywheel output or rear wheel output. Im guessing flywheel output, so Im estimating 280HP to be safe, after pluging the numbers I get a 21.xxx required rating. That seems a little high. So mabey its rear wheel power!? Either way it still seems high. Plus, what about the need for aftermarket fuel rails, pumps, ect.? I hear from some sources that serious damage could occur if the fuel demands arnt meet.
 

tomustang

Psychotic Member
Founding Member
Jun 8, 2000
3,434
2
78
McLean Hospital
Dec 2, 2004
#6
  • Dec 2, 2004
  • #6
SHM recommends you upgrading from the stock 19lb injecter when you pass 302 hp.
 

GT2000JAY

Founding Member
Oct 22, 2002
1,344
0
0
Northwest
Dec 2, 2004
#7
  • Dec 2, 2004
  • #7
For the majority of bolt-ons, stock 19# plugs are fine. I was up to 270 RWHP w/ my 19's and the car did not lean out on the dyno during three WOT pulls.

That being said, with a good tune you can swap injectors anytime you feel like you're pushing your luck. I swapped to 30's anticipating cams and P & P heads with no driveability issues.

There is nothing to be gained from injectors except the ability to meet the fuel demands of more horsepower.

When you're making enough power to require an injector upgrade, it's a good idea to start looking at the fuel supply to the injectors. In a typical returnless system, the stock rails are adequate. The fuel pump is another matter. The most common upgrades seem to be the Aviator pump, the Focus pump or the '03 Cobra dual pump/tank upgrade.

I'm not an expert, but I have experimented with my own set-up quite a bit.

Jay
 
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billyfe390

New Member
Aug 18, 2003
573
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0
Dec 2, 2004
#8
  • Dec 2, 2004
  • #8
GT2000JAY said:
For the majority of bolt-ons, stock 19# plugs are fine. I was up to 270 RWHP w/ my 19's and the car did not lean out on the dyno during three WOT pulls.

That being said, with a good tune you can swap injectors anytime you feel like you're pushing your luck. I swapped to 30's anticipating cams and P & P heads with no driveability issues.

There is nothing to be gained from injectors except the ability to meet the fuel demands of more horsepower.

When you're making enough power to require an injector upgrade, it's a good idea to start looking at the fuel supply to the injectors. In a typical returnless system, the stock rails are adequate. The fuel pump is another matter. The most common upgrades seem to be the Aviator pump, the Focus pump or the '03 Cobra dual pump/tank upgrade.

I'm not an expert, but I have experimented with my own set-up quite a bit.

Jay
Click to expand...

 
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