Ohhhhhhhhh...I didn't know we were making up numbers!!!! In that case I wanna play this game too!!

96lb injectors at 13%IDC at 4psi base fuel pressure also won't support 1200hp!!

and

28lb injectors at 100% IDC at 100psi base fuel pressure also won't support 1200hp! Damn I'm good...and damn it I can do this all day!!


Why??? Did you even read the article?? They are trying to blow the motor up! Why the hell would they care about running the injectors at 75-80% IDC and the fuel pressure at 58psi? This set-up wasn't intended to be reliable, it was meant to grenade. You do understand that don't you?

While your dad's out racing, my dad's busy porking your mom. Go Daddy Go!!

 

FYI, and those who tune can back me up... but IDC are based on the available cycle time that the intake valve is opened. Manufactures aim injectors to hit a target of 80% of the valve open time and call this the IDC, or the amount of time that an injector needs to hit a target AFR at WOT. Injectors are therefore sized to hit this target as bigger or smaller injectors become difficult to maintain/operate/and maintain day-to-day reliability. When an injector surpasses 100% IDC, that simply means that said injector requires more time to dump fuel than the available time that the intake valve is opened. In this case fuel puddles on the top of the intake valve until the next cycle occurs. Two things then happened. Fuel is now just being flooded into the combustion chamber, and the atomizing affect of fuel injection is now negated. I.E. similar to gravity feeding a motor.

So in conclusion, YES its possible to run 100%+ IDC do to the fact that it not the capability of the injector that is being rated.

 

I don't use injectors anymore. I just put my thumb over the end of a garden hose and spray into the engine. Flows way more.

 

so i was correct in what i said earlier, if you open the injector before the valve, you can get more than 100% idc.

 

Not really dependent on that. It is based on pulse width (how long the injector is powered in millisecond) and cycle time (RPMs converted to milliseconds*2 since 2 revolutions is one cycle).

I agree that an injector cannot be opened for more than 100% of the time, by definition, but that is not what IDC is measuring, it is measuring the fueling needs related to the injector flow (so it can be greater than 100%, indicating you need a bigger set of injectors).

Formula is IDC = (IPW * rpm) / 1200, sooooo if your injector pulse width is 20ms and you're turning 7,000 RPM, you're at 116.7% IDC... holy crap, it's more than 100%!!!

 

Thank you Spoolin! That's exactly what I wanted to mention! I mean, I'm positive that whoever did this test, DID NOT think that this motor would make 1200 HP, which is why they only had 75 pounders. So let's say they were running 58psi and they hit the limit of the injectors (100-125% idc) but they hadn't blown the motor yet... If you were in this situation, what would you do? Go buy some 4 to 5 hundred dollar injectors because these didn't flow enough with stock rail pressure? Or, because its just on an engine dyno and all you wanna do is blow it up, would you just turn the ****/bolt/screw, whatever it may be, and increase the FP and, if you know what I mean, instantly greatly increase the injector size?

 

while they do claim they were trying to blow it up, they also stated that they wanted to see how much hp would cause component failure. they did what they needed to do so that you could be absolutely certain it was the components that failed, not some other factor.

in this case, the limiting factor was the ignition, had that not failed, how much farther could they have gotten with stock bottom end?

 

Dude, just stfu and go back to your own little Ford world where mythical things cant happen, LSX FTMFW!!!!!!!!!!

 

 

Did anybody even calculate what size injectors and base pressure needed (theoretically)?
.6 BSFC at 63 PSI base pressure theoretically will support 1203hp at 100% duty cycle with 75 lb/hr injectors.....remember this motor doesn't have any accessories either. And that's not taking into account that most injectors are rated at 43.5 PSI..


RC Fuel Injection