clintonvillian
Famous Member
Guy's, I am getting ready to order some parts and I am muddling my way through this. A fault of mine is I like to understand the numbers (engineer brain). So see if I am looking at this correctly.
All along I have wanted this build to be in the 400 HP, 400 torque range. However I want the ability to grow if I so desire. Using various calculators I am coming up a bit short on my injectors at 60 lb/hr getting to the 500 hp range.
I have been looking at these injectors:
https://zzperformance.com/products/siemens-deka-60-injectors-6
Static Flow Rate @ 43.5 PSI ( 300kPa ) w/Gas: 60 lb/hr
Static Flow Rate @ 87.0 PSI ( 600kPa ) w/Gas: 85.7 lb/hr
In regards to the pump, the walbro GSL392 is rated at 255LPH @ 50 PSI (max). That means at 500HP and 10 psi, the Base pressure would have to be 40 PSI, to keep from exceeding the max pressure rating. This would limit the 60LB/hr injector to 57.5 LB/hr with this pump. At .75 BSFC this limits the HP to 368.
So it seems I need to go to bigger injectors, or a higher rated pump to push the 60lb injectors harder? Am I correct? Or do I need to back off of the BSFC and recalculate?
Next question is in regards to Sequential injection and O2 location. I was under the assumption that in order to tune for sequential I needed an O2 sensor in exhaust port (6 in total). However talking to a local with a dyno, he says I do not. He said best bet would be to collect both collectors into a y pipe and install my O2 sensor there for a dyno run to tune. Is this correct? Can we setup sequential injection this way?
All along I have wanted this build to be in the 400 HP, 400 torque range. However I want the ability to grow if I so desire. Using various calculators I am coming up a bit short on my injectors at 60 lb/hr getting to the 500 hp range.
I have been looking at these injectors:
https://zzperformance.com/products/siemens-deka-60-injectors-6
Static Flow Rate @ 43.5 PSI ( 300kPa ) w/Gas: 60 lb/hr
Static Flow Rate @ 87.0 PSI ( 600kPa ) w/Gas: 85.7 lb/hr
- Looking at 500 HP and a .75 BSFC, that leaves me at 62.5 lbs/hour at 100%. At 80% that is 78 lbs/hr. Am I being too conservative with .75 BSFC for a supercharged engine?
- Next question is about the injectors themselves. It appears if I increase fuel pressure the injectors output increases. Does that affect the duty cycle?
- Based on 500 HP, 43.5 psi Base Fuel pressure, and 10psi boost, the calculator says I need 210LPH @ 53.5 psi. Does this mean the regulator should be set to 53.5 psi, or does this mean the pump needs to be capable of 53.5 psi, and regulator is set to 43.5 psi?
- Do I need 80 lb/hr injectors? Or would you let that fall into that 80-100 percent range since you will only be using the full rating at the higher HP and a conservative BSFC?
In regards to the pump, the walbro GSL392 is rated at 255LPH @ 50 PSI (max). That means at 500HP and 10 psi, the Base pressure would have to be 40 PSI, to keep from exceeding the max pressure rating. This would limit the 60LB/hr injector to 57.5 LB/hr with this pump. At .75 BSFC this limits the HP to 368.
So it seems I need to go to bigger injectors, or a higher rated pump to push the 60lb injectors harder? Am I correct? Or do I need to back off of the BSFC and recalculate?
Next question is in regards to Sequential injection and O2 location. I was under the assumption that in order to tune for sequential I needed an O2 sensor in exhaust port (6 in total). However talking to a local with a dyno, he says I do not. He said best bet would be to collect both collectors into a y pipe and install my O2 sensor there for a dyno run to tune. Is this correct? Can we setup sequential injection this way?