Cody that's some excellent work.
Going on your findings, I think that I am going to keep my black CPS. Lower cylinder pressures.

 

OK Kwik, you've got my attention, please elaborate.

 

I think we need to figure out what the expected advance would be.

 

Like I said, I am sure that the injection advance is not enough to harm anything, but then again, I don't haul tons of weight. Wait!! I've got PMR's. Oh well, I'm looking for an excuse to tear the engine down anyways and go ape-stuff with it.

Elaborating some more:

I think that the reason we're seeing mixed results with this sensor is about the same reason that manufacturers' specific ignition timing (on old-school gas engines) isn't worth a crap and the only way to really get an engine running good is to advance the timing until detonation occurs then back off....AFTER the timing curve has been maximized.

Unfortunately all of you know that it's not that simple with a diesel, but we've all got different states of tune, different elevations (which makes a HUGE difference), and different ways we drive. I have since sold my Superchips 1705 and have been running with just the 'blue' CMP sensor. I still get the "injector rattle" that I never got with the 'stock' CMP sensor, but not as quiet now......hmm.

Which brings me to this point: With something as GENERIC as the 1705 tuner that is supposed to work on all 7.3L PSD engines and is not tuned specifically to one engine, the programmed injector timing to go with the increased fuel is probably nowhere as aggressive as it could be to make maximum efficiency. Maybe that's why I (and others) had noticed such drastic changes in economy. Who's to say?

Pop,

That's a great idea, but it will have to wait until next time I go to my friend's house. I can't download pictures to the site from my work computer. I will definitely work on getting some examples up here.

I'll be back with some more follow-up soon.

Cody

 

Excellent info. Thanks cody.

 

Cleatus21r Thats some good info. Were you able to compare the waveform from the CPS to the firing of the #1 injector to see if it changed any. That would be the best way to tell. Frim what you wrote it sounds like when the pulse turned off it was a good stright drop oon both CPS's. I have the crossover, it made it quiter at high way speeds, and the blue CPS made it even quiter. I do not know about mileage yet.

 

And/Or unless you are already dumping in lots of timing with an older chip, like many of us already are. I understand the newer chips don't rely on "just" timing like some of the old chips and programmers do... I have the dreaded PMR disease myself, and cylinder pressure is always right there on my mind when figuring out a "safe" new power adder.

Thanks for posting your findings. I think this is just about the first "REAL" data anybody has come up with to date on our new lilttle blue friend.

 

Since the 'blue' CMP sensor turns off "before" the 'stock' one does, the injectors WILL fire sooner. The CMP is ONLY AN INPUT to the ECM which determines when it tells the IDM to fire an injector.

If you're wondering about ACTUAL injector timing, no, I can't do that. I only have 2 inputs to my scope and I don't have the ability to actually monitor all 3 of the parameters at once (injector signal from IDM/crankshaft location/CMP status) that would allow me to "see" actual timing changes. However, from the data I have collected thus far, there IS a slight timing advance taking place.

Cody

 

Does anybody know if it is possible to use the #1 injector pulse to fire a good old fashioned timing light or how to hook one up to work? I have the Blue, a stock and a timing light. I'd be more than willing to mark the damper, and compare the difference between the two. I just don't know how to make the light work.

 

We all know that the compression ratio is fixed and that the standard Otto cycle engine generates more pressure in the combustion chamber at the point of ignition to push the piston back down and generate usable power.
My education is very limited on this next subject but I know enough to try and explain but I may get some of the terms wrong
There is fixed compression and there is dynamic compression. Dynamic compression is adjustable via cam timing, overlap, engine speed, turbo boost, ignition/injection timing, etc. We all know that for an engine to make the best power the combustion event must begin at some point before the crankshaft reaches top dead center. The earlier in the cycle the combustion begins the more pressure must be overcome by the piston traveling up and then back down again. Start the combustion too early and the cylinder pressures go way up.
I think it's in this thread where someone posted the dyno numbers. Higher HP but lower torque numbers with the blue and lower HP but higher torque with the black. A little more advance timing will do that, you have to raise the rpm to be able to utilize the earlier injection event. The flame front travels at a certain speed. I think it's dependant on how compressed the air fuel ratio is, but not sure on that point. Detonation on a gas engine comes to mind.
Think about the whole combustion event in 1 degree increments. The earlier timing and subsequent larger flame front before the piston has reached TDC.

 

Thanks for that explaination Kwik. I am assuming from your previous post that you feel that the advanced timing as expertly explained by Cody (even though above my comprehension level) is more than what you would feel comfortable with and could be detrimental to the longevity of the engine even though you have forged rods! With that said along with my terminal PMRitis, I need to gather more information.

Soooo...I am soliciting and very interested in people's opinions that are in the know about this stuff as yourself, as to whether or not to pull the blue and revert back to black.

 

If you are running light on the weight, IMO the blue is better. I use my truck to tow a 14k trailer and the GVW ends up being 24k. IMO it's better to use the black one in that case.

 

Actually Kwik, the "Blue" yields less HP and more torque.

blue cps 389hp and 738tq

Ford cps 397hp and 712tq.


These number have been confirmed at other sites (+/- of course).

 

whos pulling hp and torque numbers like that, wow!

 

Here are some numbers

780 RPM engine, each slot pulse is 6.58 ms, and cam timing advance is 0.439 ms per deg, and engine timing would be 0.219 ms/deg. If you know the time shift in the waveform, you can calculate the deg of adv.

3000 RPM, slot pulse = 1.67 ms, engine timing is 0.056 ms/deg. Anyone know the processor speed in our PCM?