U D C

Hey AH64ID what are you using to measure where you are at for engine load? Our are you just guessimating in using throttle position and RPM?
Thanks for your input..
 
Jehri said:
I know how you feel, mine has also gone MIA, went from Fox Island WA to Kent WA on the 13th & never left, now its gone. Didn't know UDC worked on a stage coach.
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UDC is not lost yet, It has been found in LA, Wow, 5 days to get from WA-CA, at this rate, I think it will be NEXT week before I see it. I don't understand why it would go to CA from WA (1200 miles) when I live north (160 miles):doh:
 
Thanks AH64ID. I have an Ultragauge as well and I was hoping that it would work. So can I assume I should just load sw7 then alter the duration table first to clean some smoke. Then start tweaking a little at a time between Timing and rail pressure?
 
Hey AH64ID One last thing before I start toying around. In the beginning did you mess with tq setting or did you leave it? I'm think I might want to set that early in the process and then no mess with it that much.. Any thoughts?

Thx
 
cj42 said:
Thanks AH64ID. I have an Ultragauge as well and I was hoping that it would work. So can I assume I should just load sw7 then alter the duration table first to clean some smoke. Then start tweaking a little at a time between Timing and rail pressure?
Click to expand...

I started with timing, and got it to where I liked it, and then worked duration.

But start with small changes.

cj42 said:
Hey AH64ID One last thing before I start toying around. In the beginning did you mess with tq setting or did you leave it? I'm think I might want to set that early in the process and then no mess with it that much.. Any thoughts?

Thx
Click to expand...

I left it close to stock for the first tuning, then once the tune was how I liked it I worked the torque management.

It's called torque management, but think of it as low rpm fuel rate. So it still references the tables you built, but can allow for more fuel than stock. I have my low tq setting lower than stock, and then gradually allow more than stock by about 15%. I found this to be very smooth on the throttle, and if I need the added power it's still there.
 
Came home today and now have a USB key to start learning this software..

Thanks Bob!

Now I just need my turbo to come back so it can go back in the truck.
At least this will give me a little time to try and get a File together to load.
 
Okay, so this is going to be a quick lesson on checking your peak timing. The purpose in this is to make sure you don't have too much timing for your fuel. It's possible to have a low timing number, say 16° but not have enough fuel for that to be optimal. A 50:50 split (BTDC/ATDC) seems to work good for heavier fueling. A little more if you are really trying to squeeze every hp out, maybe 51-52 BTDC or a little less if you don't want quite as much piston heat, 45-48. Those are rough numbers I have played with, but motor mods will have effects as well.

With the way the stock maps are laid out it's pretty easy to check 100% load timing, a lot more difficult to check lower loads. But with some common sense you can do a lot just knowing what peak timing should be.

So lets look at a stock 04.5-07 tune. For this lesson we will leave duration and pressure stock, just messing with timing.

This is a stock duration map with additional labels. What's important to note is that rpms is really load and load is pressure. 100% load is the only one that isn't appox, it's really 100% load. The rest are for reference to an OBDII reader and not necessarily to match the load on the side of the timing/pressure table (which is why anything but 100% is harder to calculate).

When the ECM goes to calculate the desired pulse width (injector open time) it looks at 2 tables. Pressure and duration, with pressure being first. Lets calculate the desired peak timing at 4 rpms, 2000, 2400, 3000, 3200.

So we first reference the pressure table. At 2000 rpms and 100% load the pressure is 20,885 psi. We then go to the duration table (one below with labels). You will notice that 20,885 is not listed on the left column, so now we have to do some math. There is a 23,206 row and a 20,305 row, with 2,901 psi between them. 20,885 is 550 psi above 20,305 and 550/2901 is 19%.

The next thing we look at is duration at 100% load. At 20,305 the duration is 2156us and at 23,206 it's 2005us, with a 151us difference. You will notice that as pressure increases the duration decreases for a given load, this is because the pressure forces the desired fuel out faster.

So we now take our 19% difference from the pressure and multiply it by 151 for 29us difference. We subtract that 29us from 2156us. This gives us a pulse width of 2127us.

So know we know how long the injector is going to be open for we can figure out when to start the injection event. A crankshaft has 360° of rotation, and by using rpm's we can calculate how long it takes to go 1° at any given rpm. Lets start with 2000 rpms. 2000 rpms is 33.33 rotations per second, multiplied by 360° gives us 12,000 deg/sec. A microseconds (us) is 1,000,000th of a second, so 1,000,000 divided by 12,000 gives us 83us per 1° of rotation.

Next you take the total injector open time, 2127us, and divide it by 83. That gives us 25.6° of total injector open time.

Let's say we want a 50:50 split of BTDC/ATDC. Multiply 25.6 by 0.5 and you get 12.8°. Thus we would set our timing at 100% load, 2000 rpms at 12.8°.

"Now lets look at 2400 rpms on the stock tables. Commanded pressure is 22,336. Since 22,336 falls between row's on the duration chart we have to do the math again. 22,336-20,305= 2031. 2031/2901=70% . At 20,305 the duration is 2156us and at 23,206 it's 2005us, with a 151us difference. .70*151= 105us. 2156-105=2051us.

At 2,400 rpms it takes 69us per 1° of rotation. 2051/69=29.7° of injector open time. Same thing 29.7*0.5=14.9° of timing. "



Now lets look at 3,000 rpms. Commanded pressure is 23,207 (same as 23,206), which happens to be one of the columns on the chart so no math is needed. 23,206 and 100% load is 2005us. At 3,000 rpms it takes 56us for 1° of rotation. 2005/56=35.8°. 35.8°*.5= 17.9°.

Now lets look at 3,200 rpms. Commanded pressure is 23,207, which happens to be one of the columns on the chart so no math is needed. 23,206 and 100% load is 2005us. At 3,200 rpms it takes 52us for 1° of rotation. 2005/52=38.5°. 38.5°*.5= 19.3°.

Pay close attention to the 3,000 and 3,200.. the pulse width is the same, but the injector open time is just under 3° longer at 3,200 due to the increased speed of the crankshaft.

So now you are able to calculate what your peak timing should be based on pressure/duration tables and a given rpm. When the load is less than 100% you need to have less timing than 100% load, or you will be injecting all the fuel much sooner and that can lead to increased piston heat and cylinder pressure.

Duration-1.jpg
 
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Man, cut-and-paste and import / export with Excel functions should be added in the next UDC version.

This searching for numbers and writing them down to transfer into Excel routine is cutting into my driving time!

Via searching the EFI web page I found a spreadsheet version for the Cummins EFI Live timing calculator and have been modifying it the past day for use with UDC.
 
Stock timing calc...

stockcalc.png



My personal Smarty TNT/R built by Marco 4 years ago at our shop on the dyno...

smartycalc.png



My personal drag tune built by me with EFI....


pullcalc.png



And finally my personal street tune that is smoke free and gets upper teens with a single 66mm...

streetcalc.png



Purpose of this is to show that a calculator will only get you so far...while its a great "tool"...like an engineer who designs a house from plans...until you see it in real life...it may or may not work.


While I completely respect the hard word done on posting your personal calculator...I just dont want people to think that its the ONLY way to tune...I am just trying to show that its just a TOOL and not a end all.
 
2007 5.9 said:
While I completely respect the hard word done on posting your personal calculator...I just dont want people to think that its the ONLY way to tune...I am just trying to show that its just a TOOL and not a end all.
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Excellent point!

I meant to throw a blurb in there about that, but forgot. It's a great starting point, but not always the 100% answer.
 
Got my base tune written late last night after about 5 hours (3.5 on timing). I basically took the best tune I ever ran with SSR and converted it as close as possible to UDC and then tweaked it in several areas based around what I needed the truck to do. Mostly in spool up areas and tuning some low end smoke out (I have really crappy air where I live and daily drive the truck). I've still got a couple hundred miles of clutch break in time before I can test out the upper end of the tune but so far, for not breaking 2400 rpms or more than 25psi boost, it is SOOOOOO much smoother and feels a lot stronger from down low all the way up to shift points.

I've got some things to adjust here and there but so far, very happy with the base tune and the results. Thanks Bob and Marco.
 
Just got it running again this afternoon, first time in three months so didn't want to beat on it.

I put on a stock 6.7 cp3 today to get it running while I am waiting on the rest of the parts to do dual cp3's.



Ill lean into it a bit on the way home and let you know.

Engine Load, correct?
 
I completely understand!

Yes engine load %. I can only get mine to read to 71%. It still follows the map though.
 
AH64ID said:
When the ECM goes to calculate the desired pulse width (injector open time) it looks at 2 tables. Pressure and duration, with pressure being first. Lets calculate the desired peak timing at 4 rpms, 2000, 2400, 3000, 3200.

So we first reference the pressure table. At 2000 rpms and 100% load the pressure is 20,885 psi. We then go to the duration table (one below with labels). You will notice that 20,885 is not listed on the left column, so now we have to do some math. There is a 23,206 row and a 20,305 row, with 2,901 psi between them. 20,885 is 550 psi above 20,305 and 550/2901 is 19%.

The next thing we look at is duration at 100% load. At 20,305 the duration is 2156us and at 23,206 it's 2005us, with a 151us difference. You will notice that as pressure increases the duration decreases for a given load, this is because the pressure forces the desired fuel out faster.

So we now take our 19% difference from the pressure and multiply it by 151 for 29us difference. We subtract that 29us from 2156us. This gives us a pulse width of 2127us.

So know we know how long the injector is going to be open for we can figure out when to start the injection event. A crankshaft has 360° of rotation, and by using rpm's we can calculate how long it takes to go 1° at any given rpm. Lets start with 2000 rpms. 2000 rpms is 33.33 rotations per second, multiplied by 360° gives us 12,000 deg/sec. A microseconds (us) is 1,000,000th of a second, so 1,000,000 divided by 12,000 gives us 83us per 1° of rotation.

Next you take the total injector open time, 2127us, and divide it by 83. That gives us 25.6° of total injector open time.

Let's say we want a 50:50 split of BTDC/ATDC. Multiply 25.6 by 0.5 and you get 12.8°. Thus we would set our timing at 100% load, 2000 rpms at 12.8°.

Now lets look at 2400 rpms on the stock tables. Commanded pressure is 22,336. Since 22,336 falls between row's on the duration chart we have to do the math again. 22,336-20,305= 2031. 2031/2901=97% (I'm getting 70%). At 20,305 the duration is 2156us and at 23,206 it's 2005us, with a 151us difference. .97*151= 147us. 2156-147=2009us.

At 2,400 rpms it takes 69us per 1° of rotation. 2009/69=29.1° of injector open time. Same thing 29.1*0.5=14.6° of timing.

Duration-1.jpg
Click to expand...

First off, I cant thank you enough for all the great information. I've been trying to soak it all up, but I'm coming out with different math for the 2400rpm range. This is what I'm getting.

At 2400rpms and 100% load, pressure is 22,336.

22,336 falls between 20,305, and 23,206 on the duration chart

22,336-20,305= 2031. 2031/2901=.70 (2901 being the difference between 20,305 and 23206)

At 20,305 the duration is 2156us and at 23,206 it's 2005us, with a 151us difference. .70*151=106us. 2156-106us=2050us.

At 2,400 rpms it takes 69us per 1° of rotation. 2050/69=29.7

29.7*0.5=14.85degrees or 14.9 degrees.

Is that correct? It's not much of a difference, I'm just trying to wrap my head around all this:Cheer:

Thanks
Jason
 
Jason,

2031/2091=0.9713055954088953 using my calculator?

I am at a similar step to you grabbed a couple of XLS sheets I found on the net.. reading and making my own xls to work from.. based on all the Great info..

AH64ID,
I have purchased an Ultraguage to use as a tool on truck and my TDI..
What guages on the Dodge have you selected on UG to benefit UDC tuning?
 
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