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Got your Horse Power.. Fuel Injector Formula

  • Thread starter Thread starter GTR_Stang03
  • Start date Start date Apr 14, 2006

GTR_Stang03

New Member
Jul 29, 2003
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Apr 14, 2006
#1
  • Apr 14, 2006
  • #1
Fuel injector size Formula:

Eng HP x BSFC
______________ = Inj. lb/hour

No. of Inj. x 0.8


BSFC=0.4-0.6 (0.55 is used)


Have a nice day!
 

DropTopPony

Noob Slayer
Founding Member
Aug 13, 2002
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south jersey
Apr 14, 2006
#2
  • Apr 14, 2006
  • #2
ummm thanks
 

Gearbanger 101

Straight Outta Locash
20+ Year Stangneter
Aug 10, 2002
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Ontario, Canada
Apr 14, 2006
#3
  • Apr 14, 2006
  • #3
That's a nice simple formula, but you're about 7hrs too late with this thread.
http://forums.stangnet.com/showpost.php?p=6076684&postcount=12

....and a brake specific is going to depend on whether you're running a power adder or not. You'll want closer to 0.45-0.50 for a N/A set up because 0.55-0.60 is more for a supercharged engine......even 0.65 for a turbocharged one according to the formula.
 

GTR_Stang03

New Member
Jul 29, 2003
53
0
0
Apr 14, 2006
#4
  • Apr 14, 2006
  • #4
The brake spacific is close enough to give these guys and gals a precise estimate of the fuel injectors needed.
.04 to .06 is used for stock to SC engines anyway.
 

98stangv8

Active Member
Oct 3, 2003
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0
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fayetteville, nc
Apr 14, 2006
#5
  • Apr 14, 2006
  • #5
GTR_Stang03 said:
Fuel injector size Formula:

Eng HP x BSFC
______________ = Inj. lb/hour

No. of Inj. x 0.8


BSFC=0.4-0.6 (0.55 is used)


Have a nice day!
Click to expand...

using this formula...I should be using about 25 lb fuel injectors...I have 362 hp x .45 ///8 x .8

I am running 19's now, and haven't had any problems and my a/f ratio is perfect. Am I running too high on the duty cycle?

Thanks!
 

Gearbanger 101

Straight Outta Locash
20+ Year Stangneter
Aug 10, 2002
9,457
1,377
234
Ontario, Canada
Apr 14, 2006
#6
  • Apr 14, 2006
  • #6
98stangv8 said:
using this formula...I should be using about 25 lb fuel injectors...I have 362 hp x .45 ///8 x .8

I am running 19's now, and haven't had any problems and my a/f ratio is perfect. Am I running too high on the duty cycle?

Thanks!
Click to expand...
It's possible to run the injector past the 80% duty cycle level (which you are most certainly doing), but not very efficient. You'd be better off economy wise and for safety sake in case of failure to upgrade and tune for a bigger injector. I'd recommed a set of 30's personally. Just as easy to tune and will keep them well under 80%
 

GTR_Stang03

New Member
Jul 29, 2003
53
0
0
Apr 14, 2006
#7
  • Apr 14, 2006
  • #7
Actually you should be running 30#. to be closer.

You could be...
 
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