LS1 Edit - Fuel Curve/Map Questions
On The Tree
Joined: Nov 2001
Posts: 108
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Re: LS1 Edit - Fuel Curve/Map Questions [quote]Originally posted by Pro Stock John:
<strong>Magnus: I had heard something like three years ago that +/- 7% Ltrims were considered okay by GM.
[ January 25, 2002: Message edited by: Pro Stock John ]</strong><hr></blockquote>
From what I heard it was actually like +/-10% john. I was told by a tech who tuned vettes at chevy for 20 years.
have you seen this formula foe injector flow?
Injector flow rate@(lb/hr)=
Engine h.p. x bsfc divided by number of injectors x .8
bsfc is Brake specific fuel consumption which is determined by engine dynamometer measurements. If I remember right bsfc ranges from .4 to .6 Using .5 is a good estimate.
now the .8 is taking into consideration an injector pulsed time of 80% duty cycle at WOT.
So if you for example take a small block 350 at 400hp. if you plug in the numbers into the formula you come out to 31 lb injectors.
I hope I made a little sense and am not making an *** out of myself.
<strong>Magnus: I had heard something like three years ago that +/- 7% Ltrims were considered okay by GM.
[ January 25, 2002: Message edited by: Pro Stock John ]</strong><hr></blockquote>
From what I heard it was actually like +/-10% john. I was told by a tech who tuned vettes at chevy for 20 years.
have you seen this formula foe injector flow?
Injector flow rate@(lb/hr)=
Engine h.p. x bsfc divided by number of injectors x .8
bsfc is Brake specific fuel consumption which is determined by engine dynamometer measurements. If I remember right bsfc ranges from .4 to .6 Using .5 is a good estimate.
now the .8 is taking into consideration an injector pulsed time of 80% duty cycle at WOT.
So if you for example take a small block 350 at 400hp. if you plug in the numbers into the formula you come out to 31 lb injectors.
I hope I made a little sense and am not making an *** out of myself.
Staging Lane
Joined: Nov 2001
Posts: 75
Likes: 0
From: Illinois
Re: LS1 Edit - Fuel Curve/Map Questions I read on a website that bsfc ranges from .40-.65
I think NA motors were in the range of .40-.50
Blowers were in the range of .50-.60
Turbos were in the range of .55-.65
I think NA motors were in the range of .40-.50
Blowers were in the range of .50-.60
Turbos were in the range of .55-.65
On The Tree
Joined: Nov 2001
Posts: 191
Likes: 1
From: Dallas, TX
Re: LS1 Edit - Fuel Curve/Map Questions [quote]Originally posted by pugsLT1:
<strong>I read on a website that bsfc ranges from .40-.65
I think NA motors were in the range of .40-.50
Blowers were in the range of .50-.60
Turbos were in the range of .55-.65</strong><hr></blockquote>
Actually the more efficient a motor becomes the lower the BSFC number becomes. So with a highly efficient motor like with a turbo setup, BSFC would be much less than .50
<strong>I read on a website that bsfc ranges from .40-.65
I think NA motors were in the range of .40-.50
Blowers were in the range of .50-.60
Turbos were in the range of .55-.65</strong><hr></blockquote>
Actually the more efficient a motor becomes the lower the BSFC number becomes. So with a highly efficient motor like with a turbo setup, BSFC would be much less than .50
TECH Addict
Joined: Nov 2001
Posts: 2,207
Likes: 0
From: College Station, Tx
Re: LS1 Edit - Fuel Curve/Map Questions I would be suprised to see a streetable turbo under 0.50 BSFC though. The lower the BSFC the more effecient, but any kind of FI setup is going to be a good bit higher in BSFC than a comparable NA setup. Just the nature of the beast.
Chris
Chris
Launching!
Joined: Dec 2001
Posts: 263
Likes: 0
From: Jacksonville, FL
Re: LS1 Edit - Fuel Curve/Map Questions OK, if I take my 473 RWHP nitrous pull on the dyno into account whereas my nitrous is a dry shot (using injectors for fuel enrichment) and you calculate 15% drivetrain to reach a ~550 crank HP number:
(550x0.5) / (8x0.8) = 42.9
My injectors are only the stock '98 injectors of 28 lbs. Am I in the danger zone? How can my O2's still be running rich at 930mv on my nitrous pull?
<img src="images/icons/confused.gif" border="0">
(550x0.5) / (8x0.8) = 42.9
My injectors are only the stock '98 injectors of 28 lbs. Am I in the danger zone? How can my O2's still be running rich at 930mv on my nitrous pull?
<img src="images/icons/confused.gif" border="0">
On The Tree
Joined: Nov 2001
Posts: 191
Likes: 1
From: Dallas, TX
Re: LS1 Edit - Fuel Curve/Map Questions [quote]Originally posted by Jax White TA:
<strong>
My injectors are only the stock '98 injectors of 28 lbs. Am I in the danger zone? How can my O2's still be running rich at 930mv on my nitrous pull?
<img src="images/icons/confused.gif" border="0"> </strong><hr></blockquote>
Have you increased fuel pressure from 60psi?
<strong>
My injectors are only the stock '98 injectors of 28 lbs. Am I in the danger zone? How can my O2's still be running rich at 930mv on my nitrous pull?
<img src="images/icons/confused.gif" border="0"> </strong><hr></blockquote>
Have you increased fuel pressure from 60psi?
