So I am trying to compile some data for purposes of determining maximum power with a specific fuel system. If you have the following details it would be helpfull in the compilation.


Injector Brand/Model =
Max Duty Cycle =
RPM Max Duty Cycle was Acheived =
Fuel Line Size or OEM =
Fuel you are using =
Base Fuel Pressure or OEM =
Boost Pressure =
Fuel Pump Model =
Fuel Pump Voltage =
Max HP =
RPM it was Achieved =

Once I have the data I would like to update the Chart published by Tony Palo with newer pumps (See My E85 link in my sig for full back ground)




Here is some pleiminary data I have collected on the Walbro 400LPH and the Aeromotive 340LPH pumps. For my build I would like to use ID1000's and the peliminary data points to using app 4,750cc/min required to support a 550WHP Turbo S2K on E85. Meaning that either pump at increase voltage and ID1000's should support this power level without getting too close to 100% duty cycle.

 

FYI, to all I talked with an engineer at Aeromotive and verified that the pumps won't implode at higher voltage. Their response was "No, but it will reduce the service life" then they informed me that they have tested at higher voltages. Since they use a centrifugal impeller increasing the speed (Voltage) increased flow more liniearly than a Walbro 255. That being said at 17.5V and 70PSI at the pump they are capible of 1.7GPM or app 6400cc/min or in our case 1600cc/min at the injector!

Now the down side, as with the Walbro they vent at 90PSI so this means at 20PSI boost pressure and factory lines the max rail pressure is going to be 50PSI. Second at this pressure and flow rate the pump would require 22AMPS to supply it!

 

Injector Brand/Model =ID1000
Max Duty Cycle =pretty sure it was right at 93-94
RPM Max Duty Cycle was Acheived =9100
Fuel Line Size or OEM =-8AN feed, -6AN return
Fuel you are using =C16
Base Fuel Pressure or OEM =85
Boost Pressure =30-31
Fuel Pump Model =Twin bosch 044 in tank
Fuel Pump Voltage = not real sure
Max HP =743( car kept spinning so it was actually higher just dont know by how much)
RPM it was Achieved =shut it out at 9100 since it spun so hard

 

Also we used a weldon red(2190 regulator i think is what it is) sorry its been a while since i messed with the car. The pressure was too much for the aeromotive A-1000 reg

 

Thank You, that is a good start, you were really pushing the limits of the 1000's!! That is 110PSI at the injector or right around 1650cc/min if you interpolate the charts! I estimate that you have a BSFC of app 0.786 at 9100RPM, which actually follows guestimates of a boosted S2000 of 0.75 BSFC if peak HP is made at redline. Which supports my pump gas data of the ID1000's with a base pressure of 43.5 producing right at 600WHP on high octane.

Now with E85 I am closer to a BSFC of 1.00 which is pretty close to 35% more fuel required. This would mean that 1604cc/min injectors at 90% duty cycle to handle 550WHP on E85 or as Jeff Evans has proved 100PSI at the rail on ID1000's.

Remember foke's BSFC changes throughout the RPM range varies with the VE of the system. So I have chosen to look at redline as this will be the fastest rate the injectors will have to pulse.

BSFC = ((cc/min / 10.5) * Duty Cycle * # Of Injectors) / HP
Brake Specific Fuel Consumption

 

^ that seems accurate, on Q16 at 20lbs I made 610hp with a re-wired Walbro & ID1000s.

 

Just ran another example and it was a 530WHP car on ID1000's using 45 PSI base pressure and it had a peak duty cycle of 70% using pump gas. This calculates to 0.66 BSFC @ 9000RPM.

Same car at 470WHP and less efficient setup did 0.67 BSFC on pump and 0.65 on race gas.

A Greddy car 0.60 at 10PSI and 260WHP.

One thing I noticed is that these are all using Wheel Horse Power, not brake so you can take all the estimates and divide by 1.15 for a more accurate number.

Corrected Examples for Flywheel HP
E85 Example = 1.0/1.15 = 0.85
Race Gas High Boost = 0.75/1.15 = 0.65
Medium Boost on Pump = 0.66/1.15 = 0.57
Greddy Low Boost = 0.60/1.15 = 0.52

So as it stands I am going to estimate that on pump that the BSFC is app 0.60 (0.70 at the wheels) for most of the midrange builds and E85 is closer to 0.85 (0.98 for wheel HP). As we get more I will update further.

 

Injector Brand/Model = ID2000 (2200cc)
Max Duty Cycle = 56.4%
RPM Max Duty Cycle was Achieved = 9000
Fuel Line Size or OEM = 8AN
Fuel you are using = E85
Base Fuel Pressure or OEM = OEM base pressure/ 43.5psi
Boost Pressure = 22psi
Fuel Pump Model = Dual Walbro 255lph pumps
Fuel Pump Voltage = Normal running voltage with 8 gauge wire on relays.
Max HP = 625whp SAE
RPM it was Achieved =9080

If your formula is right, I have a 75.6 BSFC. My mind is blown.

 

I get 0.92 using WHP or 0.80 flywheel, using a flow rate of 2680cc/min at 65 PSI so a bit closer to 135% of the pump gas BSFC's from the other cars I looked at.

 

there are so many variables to account for, the math will never add up to be consistent when trying to compare all these different cars.

but fyi, on a 2.0 motor that's fairly tired over 100k miles. we were still able to crack 500 whp on a single walbro 255 hp (it was obviously maxed), stock lines and regulator with ID2000's on e85.