gen 7 duty cycle seems off?

[norbs]

My log is showing 97% duty cycle with 83 lb ijnectors at 5500 rpm at 20 psi boost? Can this be possible? I am not making no where the hp calculated by the injector size.

 

[quickt]

Its a calculation based on based injector size, Base fuel pressure, engine RPM, VE, AFR. Make sure you have base fuel pressure in the config right. If that is lower than your base setting it will screw things up. If all else fails I would be looking at your fuel delivery.

We were runing out of fuel at 140mph with the 83s

 

[disco stu]

Wow, really? I was in the 140s on 75's and had not hit 90% yet.

 

[TurboBuRick]

My log is showing 97% duty cycle with 83 lb injectors at 5500 rpm at 20 psi boost? Can this be possible? I am not making no where the hp calculated by the injector size.

When my injector duty cycle climbed into the 90's I went right for the fuel pump. I'm running 83's with alky 23-24psi. After I changed the fuel pump it went back down to the 60's
High duty cycle points directly to some type of fuel delivery problem. Pump, filter or regulator?

Rick

 

[norbs]

Fuel delivery "should be ok" Its a external magna fuel pump with -8 lines and -10 pickup. I will check the flow at 75 psi through the rail. I seemed to have the parameters set right. Thanks

 

[TurboBuRick]

Fuel delivery "should be ok" Its a external magna fuel pump with -8 lines and -10 pickup. I will check the flow at 75 psi through the rail. I seemed to have the parameters set right. Thanks

No problem, sounds like a killer fuel system and Im not real familiar with the gen 7 but I figured I would pass on my experiences with high duty cycle.
Just one question Is that gen 7 sequential fuel injection?

 

[norbs]

Yes the gen 7 is sequential, and provides +/- 50% individual cylinder fuel correction, but no individual timing correction. Lonnie I thought duty cycle would be based on pw and rpm. I was thinking injector size on the set up screen should not make a difference. A certain pw on any injector at a certain rpm will net a certain duty cyle. I could see the lb/hr calculation being affected though. I have not flowed the fuel system but will soon, unless my magnafuel pump is no good.

 

[HighPSI]

Duty cycle has nothing to do with anything but the percentage of time the injector is open. Check your fuel delivery.

 

[quickt]

Yes the gen 7 is sequential, and provides +/- 50% individual cylinder fuel correction, but no individual timing correction. Lonnie I thought duty cycle would be based on pw and rpm. I was thinking injector size on the set up screen should not make a difference. A certain pw on any injector at a certain rpm will net a certain duty cyle. I could see the lb/hr calculation being affected though. I have not flowed the fuel system but will soon, unless my magnafuel pump is no good.

Cal is correct. The duty cycle is basicly the time the injector is open at a given RPM. The injector size in the calc table makes no difference. I was for what ever reason was explaining the fuel calculation to see if you were using the fuel supplied. why?? I have no idea as that was not the question. Sorry
I would look at delivery.