Which do you think would be more sufficient...not by guessing...by formula or a known/proven steup. I am going to use a 32lb/hr or 36lb/hr accel bosch style injector..I allready have the 32 lb injectors...but will upgrade if I think it is necessary. worried about going static....calculations say 36.25...but not sure if these are reliable calculations or if I even have the right formula. lety me know your input......Thanks

my set up: 409 motown, callies magnum forged crank, oliver stroker forged rods, JE pistons, AFR 210 heads with major porting(guy at AFR is hand porting them, sinking valves, custom valves, chamber mods..etc will have better lift numbers than the comp package 220's..low and high), mini ram, 58 throttle body, solid roller .245/.245 cam 110 lobe sep, 280 advirtised, headers, 11.25:1 compression, 2800 pro torque converter, Toms BOE 4:11 rear dana 44, 4L80E auto trans., steel half shafts, 1350 u-joints everywhere.

Hoping for around 600HP flywheel????

Let me know your educated opinions..........no quessing please...haha

 

Either way it sounds like its going to be a monster! :reddevil I think you will make 600 horsepower or at least real close. Maybe even surprise yourself with a little more depending on the porting. Good job man. I am in the same boat as you right now with injectors. Why dont you give TPIS or Lingenfelter a call I am sure they would know in a heartbeat. Later

 

It's a close call. I don't have much head room left in my 36lb injectors. If you already have 32's, I would start off with them, if they are running out of duty cycle and it is still looking for more fuel worry about it then. The 32's will probably be close enough to try out, but if you reach your goal of 600hp, you might even want to consider 42's.

By formula alone even it is hard to call. It will be impacted alot by BSFC. BSFC is often just taken as .45 for NA engines and .5 for s/c'ed, but those are very general. In reality internal friction goes up exponentially with RPM, so in a high reving setup you loose alot more power to friction causing BSFC to rise closer to that of a super charged setup.

(hp * BSFC)/(#injectors*dutyCycle) = injector size

using BSFC of .45 and duty cycle of 85%
(600*.45)/(8*.85) = 39.7 lb/hr

using BSFC of .50 and duty cycle of 85%
(600*.50)/(8*.85) = 44.1 lb/hr

Either way it says you need more than 36 lb/hr. However, most of us rarely run at standard temp and pressure, so don't make full dyno power. But more importantly, we turn up the fuel pressure to flow more than the 36lb/hr that the injector flows at the rated 43lbs.

ie. [italic] rep square root[/italic]
(oldPressure/newPressure)^.5 * injectorRatedSize = actual injector flow
ex. 36lb injectors rated at 43psi pressure now run at 60psi.
(60psi/43psi)^.5 * 36 = 42.5lb/hr

So now your 36lb/hr injectors flow as much as a 42 @ 43psi and enough to create 600hp with a BSFC of ~.48 and still maintain a duty cycle of 85%. Push that duty cycle to 90% and.... Well I think you get the point.

Hows that for not a guess.
:crazy: