Find out, because all evidence proves they didnt make the HP advertised. Just ask the them, or redirect them here.

 

And who said they had to run their injectors at 80% IDC? We have a handful of members rocking IDC's of 115-120% on FI. Not advisable but the engine doesn't spontaneously combust either.

 

You do know what 115-120% idc means right? 100% duty cycle is the injector open the whole time 100%, can you guess what 115-120% is? Nothing more than 100%. YOU CANT GO ABOVE 100%, its always just a guess based on whats "needed or wanted". Im sorry i dont post much, but this stood out to me, there packing 10lbs of potatoes and saying they got 20lbs. Maybe a typo, but they mentioned the 75lb injectors more than once, im the last person to read magazines because of this and the biased opinions/facts ALWAYS found in all magazines.

 

Yes, I understand IDC; it's a calculation of injector pulse width vs engine RPM (actually pulse width in ms over cycle time in ms, not a guess, as you call it). My point was that just because the injector is open for the entire cycle (100%) at a certain RPM doesn't mean they can't spin the engine faster and create more HP (thus greater than 100% IDC).

 

i would bet, that since its an engine dyno, their fuel pressure is probably whatever they feel like setting it to. maybe 120psi+

if your trying to tune an engine for use in a vehicle, they would set the fuel pressure to the pressure you could reasonably run through the fuel pump you're going to use. for all out power on the dyno, they just crank it up to whatever they need to get the most out of the injectors.

 

That is true of the older fuel systems. Newer ones are bit different though. They leave the injector on outside its normal window of operation to prevent a lean condition. Mine doesn't begin to swing lean until like 125% IDC.

 

Rarely does it REALLY go above 100%, in terms of TRUE fuel flowing, after 100% its more of a "guess". The computer is really just commanding that much flow from the injectors but it cant supply, so after its just guessing how much it wants, but cant keep up. 120% duty cycle flows the same as 100% duty cycle.

 

 

Someone from the magazine should pop in here soon...

 

can't you open the injector before the intake valve opens? thereby creating more than 100% duty cycle?

correct me if i'm wrong, but i assume the idc is at 100% when it opens and closes at the same time as the intake valve. if you open it before the valve opens, you can get extra fuel into the cylinder, making the idc more than 100%

unless you're referring to the 100% idc meaning the injector hangs open continuously...