Try the siemens 60# injectors on Ebay if you really want big!
They can support upwards of 650 HP at only 45psi!
Since you are new to choosing this stuff, here are some things that can help:
With your fuel pressure regulator you can adjust that up to 60 psi for a significant increase on any injector you use and still have a safe pressure (as long as you retain stock idle settings or can tune for the new idle pressure).
Our stock contour regulators run at 55psi WOT and that helps extend the range of our injectors more than people realize too since ford/bosch/delphi injectors are rated at 45psi. Apparently siemens are rated at 45.5psi, all approximately the same.
Figure the 42# injectors flow 42 lb/hr measured at 45psi.
compute new flow rate at higher pressure of 55psi:
square root (55psi/45psi) * 42lb/hr = 46.4lb/hr(substitute values so that new pressure is always over the old pressure)
Calculate horsepower available (very rough calculations) at these flow rates:
Most people assume a brake specific fuel consumption (BSFC) for turbo engines of .65 but it seems at moderate boost levels this is not the case for the duratec. I think it would be closer to the .50-.55 range that N/A vehicles are rated at. But I'll continue an example with .50 BSFC and the reevaluated 42# injectors from above:
HP=(flow rate *0.80)/BSFC
HP=(46.4*0.8)/.55
HP=67.5 per injector
67.5x6 injectors = 405 HP
These are crank values.
Now, using BSFC of 0.50:
HP= 46.4*0.8/.50
HP= 74.24
x6 = 445 HP
Now I made ~326 wHP on 36# injectors? How did that happen at stock 55psi pressure?
36# inj. ~= 39.8# injectors at 55psi.
326 with 18% loss is about 397 HP; or 66.3 HP per injector
(39.8*0.8)/66.3 = BSFC
BSFC = 0.48
Ok, all done. Now that I have 42# injectors I'm going to assume a BSFC of about .50 and the above calculation shows I should get myself up to around 450 crank or 370 wheels. Of course that is just rough and goes by the old days assumptions of 11.5:1 air fuel ratio when I run closer to 12.3:1
Whew, that was long right? Had enough yet?
