Timing between Pilot and Main event

[Moparmatty]

I take this to mean that Pilot Timing base table (and all other density tables) are referencing Degrees Before Main Event, then? I was under the assumption that it was a TDC reference, myself, so this could cause even further curiosity and concern about my aforementioned question in regard to seeing 82+ degrees of pilot timing, since that would mean Pilot timing in reference to actual TDC would then be 82 + whatever main timing is (which I presume to be in reference to TDC).

Thanks again for your time and willingness to share.

When your pilot is showing 82* what is your main timing at the same point?

[B00STJUNKY]

When your pilot is showing 82* what is your main timing at the same point?

This is occurring at around 2000+ RPM on up and starts to taper down again around 2800 RPM, although still in the mid 60's. Main timing in this RPM range ranges from 9.5* to 20*, and Pilot pulsewidth ranges from 300 uS to 240 uS in the same RPM range.

[2007 5.9]

Pilot is referenced from SOI of main and not TDC.

[Moparmatty]

On the subject of Pilot timing, Les, does 82* pilot timing under heavy load (140+ mm3) seem excessive to you? This is occurring at around 2000+ RPM on up and starts to taper down again around 2800 RPM, although still in the mid 60's. Main timing in this RPM range ranges from 9.5* to 20*, and Pilot pulsewidth ranges from 300 uS to 240 uS in the same RPM range. Seems like there would be quite the long delay between Pulse and Main injection with such aggressive Pilot timing.

So if your pilot is showing 82* and your main is showing 20*, pilot injection is starting 102* BTDC.

[Bamofo]

Pilot is referenced from SOI of main and not TDC.

thats interesting. and why i didnt post up the calculator before i was done. Thanks that helps a lot actually. but now makes me mad i wasted my time doing all that freakin excel crap.

Ill pull out Pilot everything and clean it up. If you want to test it ill send it to you.

[B00STJUNKY]

So if your pilot is showing 82* and your main is showing 20*, pilot injection is starting 102* BTDC.

Yeah, I get that (now that I know Pilot timing references main SOI).

My question was, doesn't that seem excessive, and is there any potential danger/harm from spraying so far in advance (ie spraying outside of the bowl), or is the fact that pilot is such a small shot of fuel, it doesn't matter and isn't worth worrying about?

[Bamofo]

So if your pilot is showing 82* and your main is showing 20*, pilot injection is starting 102* BTDC.

so logging is also based of SOI and not TDC?

Just wondering...

[Moparmatty]

so logging is also based of SOI and not TDC?

Just wondering...

Yes

[Moparmatty]

Yeah, I get that (now that I know Pilot timing references main SOI).

My question was, doesn't that seem excessive, and is there any potential danger/harm from spraying so far in advance (ie spraying outside of the bowl), or is the fact that pilot is such a small shot of fuel, it doesn't matter and isn't worth worrying about?

Is it actually spraying at that point. What is your pilot mm3 at that point?

[B00STJUNKY]

Is it actually spraying at that point. What is your pilot mm3 at that point?

Approximately 13 mm3, or 270 uS through 50% over nozzles.

[Bamofo]

Yes

cool ill update the main thread and update the question. Question still stands what you guys are doing with your pilot timing.

[Kill]

After seeing all the numbers referenced here, there is a big difference the pilot events in an 03-04 truck compared to a 04.5+

[2007 5.9]

thats interesting. and why i didnt post up the calculator before i was done. Thanks that helps a lot actually. but now makes me mad i wasted my time doing all that freakin excel crap.

Ill pull out Pilot everything and clean it up. If you want to test it ill send it to you.

This is why I was looking like a jerk...I wanted to understand what you were doing and why....so you didnt make something you didnt need nor give out false calculators that were invalid.

[2007 5.9]

Approximately 13 mm3, or 270 uS through 50% over nozzles.

Sounds like you have not touched any of the Pilot Timing Adder tables...yes 82* is FAR too much...and you need to reign that in before you do damage.

You need to adjust and log so that your commanded pilot timing in the table is what you get in the log...or else your just guessing....

[2007 5.9]

After seeing all the numbers referenced here, there is a big difference the pilot events in an 03-04 truck compared to a 04.5+

You see that difference because of the different bowl and cone angle design between the two engines.

[B00STJUNKY]

Sounds like you have not touched any of the Pilot Timing Adder tables...yes 82* is FAR too much...and you need to reign that in before you do damage.

You need to adjust and log so that your commanded pilot timing in the table is what you get in the log...or else your just guessing....

Thanks, Les. I'll work on getting that reeled in. I appreciate it.

[Kill]

You see that difference because of the different bowl and cone angle design between the two engines.

Yes, I understand that, just didn't think it would be so drastic. Kind of funny that they run less overall main timing, and almost double the pilot timing. Or maybe that's why they run so much pilot timing.

[2007 5.9]

They run so much pilot for the noise control and NOx reduction...make all the power with the pilot and you can keep main timing low and keep the EPA happy with NOx.

This becomes more obvious with the 6.7's...they run 24* max Pilot and 19* max main....almost identical to the 03-04...again piston design and with the 6.7...you have EGR handle the NOx reduction..so you can run the main timing back up and use it for power instead of the Pilot crutch.

[B00STJUNKY]

Just to update, I ran a test just now to see what logged pilot timing would do with a static table. I set all 5 pilot timing tables to 20* static (meaning base, hi, med-hi, med-lo, and lo density tables), and zero'd out the ECTxIAT adder table, while leaving the coefficient table at a static value of 1.0 in every cell.

The results were that logged pilot timing reflected degrees BTDC, rather than degrees BMI (before main injection).

So, for example, if while driving at low load and main SOI timing was at -2.0* BTDC (aka 2.0* ATDC), then pilot timing would show 18* in the scanner. If the main SOI timing were at 3* BTDC, then pilot timing would show 23*BTDC.

So, as you guys mentioned, it's clear that the tables are definitely referenced as degrees BMI event.

However, it looks like there may be some conflicting info that logged pilot timing is in reference to Start of Main Injection Event timing. That seems not to be the case. It may be that in EFI Live it references degrees BMI, bit in HP Tuners scanner, Pilot timing seems to be referenced in degrees against TDC.

[B00STJUNKY]

Another update.

It seems that having set the "Adder" table to zero caused actual pilot pulse to go to zero. Scanner showed that 3 mm3 was being commanded with 20* timing BMI as was set in the table. But pulse logged zero flat the whole time.

As another test, I loaded a tune that had the pilot "Adder" table set static to 1 across the board, which resulted in the same thing. Zero pulse, 3 mm3, pilot timing following the base table.

So, it seems as though the '05 calibration could also suffer from the same mislabelling that we are suspecting in the 03-04 calibrations.

I'm currently loading a tune that has the "adder" table set to 5. If it follows that these values are max limiters rather than adders, and a value of 5 actually means 50 (as it seems to be suggested in another currently active thread), I should see my full commanded pilot timing and pulse should return.

I'll report back with my findings shortly.