Ls1 346ci SS

[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.

pugs

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

kewlbrz

[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

ChrisB

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

Jax White TA

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">

kewlbrz

[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?