PDA

View Full Version : Tuning questions..



68showngo
June 4th, 2011, 10:12 AM
I'm not sure if this is the right place to post, but kind of wanted some input before I try too much.

1. When changing the timing on the main injection, will this every get in the way of the pilot/post injection? Do I have to worry about adjusting them too when doing the main injection?

2. What's the best thing to do with the post/pilot injection? Will it hurt anything to put everything to 0 on them? Or just leave them as they are?

So far I've mostly messed with the rail pressure and main injection fuel quantity, and on my last little test I could already feel an improvement :)

GMPX
June 4th, 2011, 10:35 AM
The ECM will ensure the injection events don't overlap. The thing to think about is the pilot injection is timed off the main injection, so if you move the main injection by 10 degrees, then the pilot start also moves 10 degrees.
People tend to like to disable the post injection for fuel economy reasons, if you set the commanded rate to 0mm3 that is the best method (rather than zeroing the pulse table).
I won't get in to the debate about pilot, some like it, others don't. The engine will have more of a Diesel rattle with no pilot. The idea behind the pilot injection is it will make the main pulse burn better.

68showngo
June 4th, 2011, 10:39 AM
Ok thanks! And I figured some of that out a little better now already. I'll try disabling the pilot and see how I like it.

68showngo
June 4th, 2011, 10:48 AM
Another question.. What is the cal-flash for? I just had the idea that that might work to flash tunes instead of always the full flash. Probably not though?

ScarabEpic22
June 4th, 2011, 11:52 AM
Cal flash is for GM tunes, I havent tuned a Cummins yet but it appears you must full flash them every time. So if all you are tuning are Cummins trucks (06-07 5.9 now, no idea about the 6.7 and older 5.9s) then Cal-Flash isnt important. Might be nice to have that option grayed out when a Cummins 06-07 5.9L file is loaded.

GMPX
June 4th, 2011, 01:34 PM
Erik is correct, on the Cummins there is no choice but to do a full reflash each time (Operating System and Calibrations), with GM computers it's possible to just reflash only the calibrations which saves time, but that is simply not possible on the Cummins ECM.

68showngo
June 4th, 2011, 01:45 PM
Thanks for the replies! I've learned a lot today and have plenty to learn yet! Lol main thing is using the logging I think.. no clue on that part yet.

Sent from my DROIDX using Tapatalk

68showngo
June 4th, 2011, 03:48 PM
When changing the fuel pressures.. I noticed that under "Axis Define", a lot of the charts show 140 mm3 as the highest fuel pressure, while the "Fuel Pressure Base Table" shows 160 mm3 max stock. To up the fuel pressure do I have to modify a lot of the "Axis Define" charts too, or does it basically just go off the Fuel Pressure Base Table? Also, how do I know when I've hit the max safe fuel pressure?

I guess another question would be, do the "Axis Defined" tables always have to be modified too or how do they relate to the other tables?

2007 5.9
June 4th, 2011, 03:56 PM
Can you list the table numbers to which your refering to?? So I can look at mine to help you...

Thanks
Les

dansdieselp
June 4th, 2011, 03:57 PM
We just upped the base and air density adjust tables. You'll have to up the max parameter as well. We typically don't go higher than 180mpa.

68showngo
June 4th, 2011, 04:05 PM
D0754 would be one that looks related to D0782. But nevermind, I just now saw that the 140 is mm3 and not fuel pressure. I think the Axis Define charts mostly modify how far you can go with the tables later? Like in D0754 if you upped it from 140 mm3 to 160 mm3, you would be able to tune all the way up to 160 mm3 in D0782 instead of being limited to 140. Correct me if I'm wrong. I first discovered this in the Fuel Limiter section.

GMPX
June 4th, 2011, 04:11 PM
Yeah, but if the axis stops at 140mm3 as an example that doesn't mean the ECM doesn't know what to do beyond that, it just means you have no control beyond that point. Same with the RPM tables, if you need control at 4,500 then you should rescale the axis values that high for the tables that you need to modify. EFILive has a nice interpolation function that will blend values between two points for a nice linear line if you are rescaling an axis.
The only thing to be wary of is when you alter the axis points you need to keep in mind the values in the table stay the same. So the value at what used to be 3,500 RPM, would then become the value at 4,500 RPM.

2007 5.9
June 4th, 2011, 04:18 PM
The only thing to be wary of is when you alter the axis points you need to keep in mind the values in the table stay the same. So the value at what used to be 3,500 RPM, would then become the value at 4,500 RPM.

Yeah I learned that one the hard way....couldnt figure why my rail pressure was so high...lol

Thanks
Les

68showngo
June 4th, 2011, 05:02 PM
Ok I've played with it like 4 hours earlier today just with random different changes.. Now I went through and modified nearly everything, mostly smoothened tables and slight increases with some stuff. Like max fuel pressure to 170 or 175, 3 degrees added timing to main injection. Upped the pulse width 5% throughout on the main injection, and more.. Can't wait to test it tomorrow and hope it all works! If it goes smoothly I might start trying to learn how to use the Scan/Logging part of the tuning.

killerbee
June 5th, 2011, 01:58 AM
If it goes smoothly I might start trying to learn how to use the Scan/Logging part of the tuning.

You may come to this conclusion yourself, but the logging is the horse, and the changes are the cart. Become familiar with logging first, if you want to make predictable changes, and avoid making a mess.

68showngo
June 5th, 2011, 02:06 AM
You may come to this conclusion yourself, but the logging is the horse, and the changes are the cart. Become familiar with logging first, if you want to make predictable changes, and avoid making a mess.

Is there a tutorial somewhere on how to start with the logging?

Sent from my DROIDX using Tapatalk

killerbee
June 5th, 2011, 02:14 AM
In the help section of the software, there should be "scan tool" tutorial. The "art" of logging is something you will develop on your own, but that will get you started looking at pid's and making those baby steps toward a rewarding tune.

joecar
June 5th, 2011, 01:22 PM
...
If it goes smoothly I might start trying to learn how to use the Scan/Logging part of the tuning.+1 on what Killerbee said... learn to log first; the importance of logging cannot be stressed enough.

68showngo
June 5th, 2011, 03:07 PM
I think I know what you mean because that tune I worked on seems slower than stock.. need to figure out what it is, not that I made any major changes though. Runs good and cool too. Looking at logging right now.

68showngo
June 6th, 2011, 02:29 AM
I tried logging some stuff yesterday.. Looks like I'm not getting the amount of fuel I should be getting and dropping off too early which is exactly what it feels like. Do I use the logging to see how it's acting and then figure out where to make the changes to fix what it's not doing? I read something about auto correcting stuff somewhere and I don't know if this is even related to any of the logging and tuning on the Cummins. I figured out how to make a "map" and then log it which is how I found out about the fuel dropping off early and not getting enough. I think I need to up my pulse width?

2007 5.9
June 6th, 2011, 03:33 AM
I tried logging some stuff yesterday.. Looks like I'm not getting the amount of fuel I should be getting and dropping off too early which is exactly what it feels like. Do I use the logging to see how it's acting and then figure out where to make the changes to fix what it's not doing? I read something about auto correcting stuff somewhere and I don't know if this is even related to any of the logging and tuning on the Cummins. I figured out how to make a "map" and then log it which is how I found out about the fuel dropping off early and not getting enough. I think I need to up my pulse width?

How much mm3 are you commanding/seeing??

Is your drop in fueling happening around 2800rpms??

~Les

68showngo
June 6th, 2011, 03:38 AM
I will have to look at that again, but yes I think so. Max I think was 130 and it dropped to 115 or so by around 3k RPMs. I thought the commanded mm3 was 160, but maybe I just didn't tune something right, and I did go through nearly every table to try to get it to not de-fuel up top, but again I might have done something wrong.

2007 5.9
June 6th, 2011, 04:02 AM
I will have to look at that again, but yes I think so. Max I think was 130 and it dropped to 115 or so by around 3k RPMs. I thought the commanded mm3 was 160, but maybe I just didn't tune something right, and I did go through nearly every table to try to get it to not de-fuel up top, but again I might have done something wrong.

Correct, at 2800rpms, there is a fueling limiter that is still being looked for.

Some trucks command 140mm3 and some more...not sure why.

Log calculated load next time and report your peak number.

I've got two trucks with exact same tune, one only commands 145mm3 and the other will command 200mm3. Again both trucks have the exact same tune...

The 145mm3 truck has a peak load of 73%, while the 200mm3 truck will get to 140%.

~Les

68showngo
June 6th, 2011, 04:18 AM
Which PIDs do I select or how do I get to the calculated load?

02dodge
June 6th, 2011, 04:41 AM
Correct, at 2800rpms, there is a fueling limiter that is still being looked for.

Some trucks command 140mm3 and some more...not sure why.

Log calculated load next time and report your peak number.

I've got two trucks with exact same tune, one only commands 145mm3 and the other will command 200mm3. Again both trucks have the exact same tune...

The 145mm3 truck has a peak load of 73%, while the 200mm3 truck will get to 140%.

~Les

Hey Les Have you looked at D0791? This table is Fuel Pressure Reg., Max duty cycle, RPM Axis. I noticed while playing with a tune that this table stops at 2700rpm. I dont know if this would have anything to do with the fuel being pulled above 2700.

Patrick

2007 5.9
June 6th, 2011, 04:47 AM
Which PIDs do I select or how do I get to the calculated load?

I don't remember at the moment...I think it's in the engine status group.

~Les

2007 5.9
June 6th, 2011, 04:48 AM
Hey Les Have you looked at D0791? This table is Fuel Pressure Reg., Max duty cycle, RPM Axis. I noticed while playing with a tune that this table stops at 2700rpm. I dont know if this would have anything to do with the fuel being pulled above 2700.

Patrick

I have not, I'll look at it tonight when I get to my computer. Good looking out.

~Les

68showngo
June 6th, 2011, 04:59 AM
I upped that to 3500 RPM on this tune I tried where it dropped off at the end. I just upped the pulse width on that tune to try now and see what my fuel looks like. On my next try I will up the max duty cycle to 71, 71, 75, 79, and 83 and see what happens.

68showngo
June 6th, 2011, 05:12 AM
The numbers are mm3 of fuel from my last 3 logs. Can't wait to try and up the max duty cycle and possible monitor my rail pressure, but I gotta get back to work now...

This is stock tune, 1600-3400 RPMs 100% throttle.
121.841030 - 1600
112.567932 - 1800
108.891905 - 2000
132.082200 - 2200
132.758149 - 2400
130.535426 - 2600
137.925967 - 2800
127.064832 - 3000
100.186819 - 3200
79.094202 - 3400

This is my tune from 2000 RPMs to 3200.
120.380432 - 2000
118.993430 - 2200
114.630390 - 2400
108.229968 - 2600
101.300823 - 2800
94.328702 - 3000
86.063663 - 3200

This is my tune with 3% upped pulse width all the way through and another 15% on the top half. This obviously didn't help.. 1400-3400 RPMs
93.123489 - 1400
104.110051 - 1600
115.336275 - 1800
117.711566 - 2000
117.131694 - 2200
114.218565 - 2400
108.343699 - 2600
100.346466 - 2800
93.722258 - 3000
78.548853 - 3200
62.870810 - 3400

2007 5.9
June 6th, 2011, 05:36 AM
Good log....keep us updated with new duty cycle logs.

~Les

68showngo
June 6th, 2011, 10:51 AM
I tried logging the duty cycles.. but not sure if I'm doing it right. "Fuel Control actuator duty cycle" is what I logged and the highest number I saw on the chart was 41.1. I'm gonna go load the tune now though with the higher maximum duty cycle though and see how my fuel amounts react to that.

68showngo
June 6th, 2011, 12:12 PM
I think I'm up to Round 4 starting back from stock... I'll get this yet!

68showngo
June 6th, 2011, 01:30 PM
Best tune so far.. Upped the main injection pulse width, the whole table by 20%. Disabled post injection. Added 6 degrees to all Main Injection timing tables and smoothened them out. Smoothened Rail Pressure Table. Disabled wastegate. 35 PSI of poost and max EGTs I saw were 1300 but was scared to go fast cuz I got death wobble again earlier today. I would estimate to be about a 60 hp tune.

I also tried taking out pilot injection after 2400 RPMs, but I must have done something wrong because it right aways idled at 1000 RPMs and then when it started going down it was getting pretty rough so I just shut it off. Might not even mess with it.

2007 5.9
June 6th, 2011, 01:42 PM
How did you remove pilot?? Quantity or pulse??

Or timing??

~Les

68showngo
June 6th, 2011, 01:47 PM
Quantity, just like I was told to on the post injection which has worked just fine. Is the pilot different? Is there more that has to be modified? I totally thought I didn't change anything before 2400 which is why it seems weird why it was idling the way it was.

Dmaxink
June 6th, 2011, 02:01 PM
On thing to consider also, I like leaving the pulse stock under 30mm3 and 80mpa... For starters at least

68showngo
June 6th, 2011, 02:05 PM
Yeah maybe that would help with the way it idles I'm guessing..

Dmaxink
June 6th, 2011, 02:11 PM
Yeah, try increasing your fuel from 70mm3 and 120mpa on up and just Smoothen down a few times to say 40mm3. This will keep your idle correct

2007 5.9
June 6th, 2011, 02:28 PM
here is a screen shot of my pilot...works well for me.

~Les11077

68showngo
June 6th, 2011, 02:31 PM
Thanks, I might try that.. just not even sure what it helps besides that I feel like trying stuff...

Did you change anything on the Main injection for it to run good?

2007 5.9
June 6th, 2011, 02:37 PM
I changed nothing from my DD tune to make this pilot table work.

~Les

68showngo
June 6th, 2011, 02:44 PM
Did you use same table on the rest or leave the air density adjust tables the same? I would think you would use same table on them all?

2007 5.9
June 6th, 2011, 02:53 PM
Did you use same table on the rest or leave the air density adjust tables the same? I would think you would use same table on them all?

Yes I used that table to adjust the air density tables accordingly

~Les

68showngo
June 6th, 2011, 03:27 PM
Ok how about the coolant and intake temp adjust?

I finally got my mm3 of fuel up a bit higher.. tuned it to do 160 mm3 but got it right near 140 mm3 so I'm getting happier. That's with stock rail pressure which it seems to be staying pretty close at too. I think the biggest thing I messed up on this tune was something with the limiters.. I think it's the boost limiter. Turbo spools really slow, but once it lights it goes pretty good!

I think tomorrow I might start messing with the rail pressure and see if that'll help anything out. Not sure how high I can go on the timing or I might up that some more yet too. I definitely want to reduce some of the stuff up to maybe a 1000 RPMs, feels almost a little rough when changing from Park, Reverse, Neutral, and Drive. I tried reducing the pulse width a little down low, but I think I selected too small of a section for after smoothening them.. I'll do a bigger section tomorrow (like was posted) and see if that changes anything.

Any tips on logging are also appreciated, what to log and stuff..

1400-3200 RPMs in 3rd..

96.897644 - 1400
100.271736 - 1600
107.789853 - 1800
117.119564 - 2000
134.666151 - 2200
132.311476 - 2400
136.201038 - 2600
139.225540 - 2800
129.557107 - 3000
110.578414 - 3200

2007 5.9
June 6th, 2011, 03:42 PM
I left the adjuster tables alone

~Les

68showngo
June 6th, 2011, 03:52 PM
Ok awesome! I'll be trying that tomorrow on one of the tunes I haven't too much to yet.. Idk if this has been posted anywhere or not yet, but I'm waiting on some fuel mileage testing with removing post or both post and pilot injections. Maybe I'll just have to do some testing on my own.