Contour Enthusiasts Group Archives Forums General Dyno and Drag Dyno of 3.0L Duratec Twin Turbo

That regulator is unused, not sure why it's not just left off.

Here's the actual Bosch one:





And the stock fuel pump (foam covered) & filter (blue):



Noble uses a speed density system, no MAF at all.

42lb injectors = 440 cc/min.

Anyone upgrade their injectors? What did you get?

I have used 36# in my turbo 3L and they provided sufficient fuel for the 326 wHP dyno's. I think I could have gotten 350 out of them easily enough. I have 42# injectors for my engine so that I can take it up into the 400 HP range should it decide to hold together at those levels and if the turbo and piping is capable of it.

What to get beyond 42#? Anyone happen to know?

50#. I could never just plug in the values and get it right. I always had to tune the maf for it too.

Changed the fuel pump and filter:



http://www.fluidcontrol.net/pages/pumps.html

Changed to aftermarket Sard Sport adjustable fuel pressure regulator, with liquid filled pressure gauge, so we can keep an eye on it during the dyno tuning:



No more lean condition. W00t.

Going in for dyno next week, and hopefully turn the boost up.

No MAF here. Lots of fuel injector choices, but I'm really not used to domestic stuff. Trying to find bigger ones that fit without problems. If you can't tell, I'm a totally newbie with this kind of engine.

Installed:



Alas, waiting list for nearby dynos is 2 weeks.

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?

Now with these ratings are the injectors at 100% duty cycle or within a safe range.

Sorry,

80%
That is what the 0.80 means in the formula.
You can pick 85% as safe, or even 90% but that is about it.

Also I want to correct the earlier statement about the injectors being rated at 45psi. Some are and some aren't.
Ford used to rate them at 39psi. Some are also 44.5psi. Pick an average value since they are all pretty close.