Tips & Tricks: Things you've learned while exploring EFI Live on the Cummins

[DoghouseDiesel]

Folks,

Had an idea that may help folks as they learn to use this on the Cummins, as most of us have never had the flexibility offered by EFI.

These are some of the things I've learned so far that may help the next person that is exploring options and writing their own tunes.

1 - Save your OEM tune before you do ANYTHING else. Make copies, make several copies on different media. If you ever screw up, you'll have it to fall back on.

2 - LOG, LOG, LOG! Before making any changes, log what the truck is currently doing. This may take a week, this may take a month, but DO IT! It's like having gauges in the truck....you need to know what's going on first.

3 - When you decide you are ready to start making changes, MAKE ONE AT A TIME! It's too much of a PITA to figure out what's going on when you make multiple changes at one time. Modify, save, load, LOG! Repeat.

4 - The VERY FIRST things you want to modify are the parameters, NOT the maps and graphs. If you plan on running 4200 RPM's, modify all your parameters to reflect. If you plan to run 26K psi, modify the parameters to reflect. This will help you further down the road so that your tables line up with your intended changes. Save this file with NO OTHER modifications; this will let you use it as a base for other tunes without going back in an modifying the parameters again.

5 - Get to know the values. Understand what relation MPa is to PSI and how many microseconds of duration you really have available at a given RPM.

6 - BE CONSERVATIVE! It's like baseball....a home run is awesome, but base hits add up. Swinging for the fence often puts you on the bench.

7 - Put a sticky note right under you computer screen. On this sticky note, put the monetary value of your engine and transmission. This will help you keep things in perspective when you think, "Maybe just a little more."

Please feel free to add any tips, tricks and / or advice for the next guy.

:cheers:

[GMPX]

Great thread idea, thanks. It sounds like you are having a lot of fun tuning.

[DoghouseDiesel]

Great thread idea, thanks. It sounds like you are having a lot of fun tuning.

It is SO nice to finally be able to see what's going on.

We've asked for it for years. Obviously not just from EFI, but from the other manufacturers as well and no one would say, "Hey, this is how much timing we're adding" or "We cap the rail pressure at XXX".

It's all basic stuff that anyone tuning NEEDS; it's not a secret.

When you're dealing with $30k+ motors, both your own and customers, no one wants to guess. That's not a good way to "tune".

Now it's time to see what we can really squeeze out of it.

[DoghouseDiesel]

Okay, I posted this in it's own thread, but here's how to set up your own 2-step for launches at the track.

This allows you to set a specific RPM that makes the boost you want to launch with. You just have to figure out what that RPM is.

All you have to do is apply the brake, mat the accelerator pedal, RPM's will stop at the designated point (so long as your converter doesn't stall at a lower RPM) and you should hit your target boost pressure.

As soon as you release the brake, the engine goes wide open, just like coming off a trans brake.

Here is the setting you need to adjust.....

http://i288.photobucket.com/albums/ll189/Cumminalong/Dohouse%20Diesel%20Pics/EFI%20Live%20Screen%20Shots/2-StepLimiter.jpg

[Straight 6]

Thanks again for another great post i love step #7 lol your helping me (as well as many others im assuming) a lot and look forward to any more info you can share with us

[DoghouseDiesel]

Here's another for ya....

The question was brought up about turning off the post injection event.

What most people are seeing is a loss in HP when you do this.

Here's why....

Above 2800 RPM's the ECM reduces the total number of degrees past TDC that the main injection event can last. You go from 22* past TDC down to 14* at 4200 RPM's.

This is table C7001, Injection Shutoff vs RPM. It's under the Main Injection tab.

Bring these up and you can kill the post injection event and stretch the main injection event.

http://i288.photobucket.com/albums/ll189/Cumminalong/Dohouse%20Diesel%20Pics/EFI%20Live%20Screen%20Shots/MaxInjectionDuration.jpg

[monkeybrain]

Rich, nice work man!

[chizwizdiz]

Nice work on the post injection info!

[vortecfcar]

Here's another for ya....

The question was brought up about turning off the post injection event.

What most people are seeing is a loss in HP when you do this.

Here's why....

Above 2800 RPM's the ECM reduces the total number of degrees past TDC that the main injection event can last. You go from 22* past TDC down to 14* at 4200 RPM's.

This is table C7001, Injection Shutoff vs RPM. It's under the Main Injection tab.

Bring these up and you can kill the post injection event and stretch the main injection event.

Doghouse,

Have you verified that changing this table allows a longer pulsewidth? My tests back to back on this table show no difference in main pulse allowance or overall main injection fuel delivery. Also, changing only the values in this table gave me a no-start condition. I'm curious to hear your results if they differ from mine.

Thanks,
Nick

[Dmaxink]

Here's another for ya....

The question was brought up about turning off the post injection event.

What most people are seeing is a loss in HP when you do this.

Here's why....

Above 2800 RPM's the ECM reduces the total number of degrees past TDC that the main injection event can last. You go from 22* past TDC down to 14* at 4200 RPM's.

This is table C7001, Injection Shutoff vs RPM. It's under the Main Injection tab.

Bring these up and you can kill the post injection event and stretch the main injection event.


-------------------------------------

http://i288.photobucket.com/albums/ll189/Cumminalong/Dohouse%20Diesel%20Pics/EFI%20Live%20Screen%20Shots/MaxInjectionDuration.jpg

Make sure this is verified, because i brought all mine up and caused the truck once it surpassed 30mm3 to buck and not go. Now it has been ok to bring the bottom back up to 22 and not have anything cause the truck to act crazy, but from my logging experience it did not change the limited injection event... maybe i should try another OS but currently it made no difference.
Great writeup... i will see if i can't add a little to help the newbies also

[DoghouseDiesel]

Mine starts up and runs fine with everything brought up to 22*.

BUT, I have not run the truck up at those RPM's since putting it on.

If you're running it with the 3rd event still going, did you reduce the delay between the main and post events? With the added timing that 600 microsecond delay is going to be too much.

As soon as I have some time to strap it back down on the dyno, I'll log the upper RPM's and see what it's doing.

[Dmaxink]

3rd event has been shut off completely

[DoghouseDiesel]

I'll mess with extending the main duration when I strap it back down.

I try not to mess with timing and duration too much unless I have the truck on the rollers. Just a lot more controlled environment to work on things.

A little too much timing on the dyno is easier to see than with just the logs.

[8100 Power]

Seems your having a lot of fun with it Rich...

[DoghouseDiesel]

Getting it figured out.

Got the rail pressure setup the way I want it.

Getting the timing dialed in now.

Starting to get an idea of where I'm going with the duration. That's been a lot of math and head scratching.

Still a lot of things to dial in, but it's getting there.

[2007 5.9]

I've learned that 90% of low end smoke is entirely tied to timing....too much low end timing=smokey mess.

Also learning that 2 different trucks with similar mods....dont respond the same to the same tune....

~Les

[AFTERMATH DIESEL]

Until you are familiar with what you are doing do not change more than one thing at a time. This has been my number one question from customers that have asked me to help find an issue and most of the time my answer ig go back and start over.

Just because you change something doesnt mean it worked. If you dont log it you will never know.

[Dmaxink]

Les, too much low end timing caused the smoke? That is starting the injection event x* BTDC, more timing will typically mean less smoke, likewise less timing more smoke.... maybe you mean the main injection? Just making sure myself, nor anyone else gets confused...

Thanks,
Kory

[2007 5.9]

Les, too much low end timing caused the smoke? That is starting the injection event x* BTDC, more timing will typically mean less smoke, likewise less timing more smoke.... maybe you mean the main injection? Just making sure myself, nor anyone else gets confused...

Thanks,
Kory

If I have too much low end main timing...smoke show,and hazes at cruise. Lower the main timing some and now can have a responsive low end, with ZERO smoke on accel and cruise...however EGT's suffer.

I have run anywhere between 17-30* of main timing at 30-40mm3 at 2000 rpm's...17* nets me 750-800* of EGT's and a super clean tailpipe...while 30* nets me 600* of EGT's but a super hazy tailpipe. So I have found that so far there has to be a trade off...for now. I am certian that with time I can fine tune it in to get the maximum timing in with best EGT's and still be clean...just takes time.

Being that I live is SMOG loving California...lower smoke levels are a must, especially with the local highway patrol...LOOKING for smoking diesels to automatically send to smog station.

~Les

[DoghouseDiesel]

What I've found with it, as far as the timing goes, is if I keep the timing in the 22* - 25* range at highway cruisng RPM's the smoke is controllable.

I have it sitting at 18* at idle, but bring it up to the low 20's fairly quickly. I kind of leveled the map a bit in the cruising range to limit the smoke and the touchiness and then ramp it back up once it gets above 2200 RPM's

Same thing with the rail pressure. I bring that in fairly quick down low and limit the duration.

Unless I'm driving like a prick, it's pretty controllable.

http://i288.photobucket.com/albums/ll189/Cumminalong/Dohouse%20Diesel%20Pics/EFI%20Live%20Screen%20Shots/Timing.jpg

[Dmaxink]

Nice follow up Les, just goes to show every truck is different. Ours loves 28*. At 30* we got timing rattle and low throttle response (flame was put out)...mileage did well from 28* and bumped fuel pressure in the cruising range.

[68showngo]

Here's another for ya....

The question was brought up about turning off the post injection event.

What most people are seeing is a loss in HP when you do this.

Here's why....

Above 2800 RPM's the ECM reduces the total number of degrees past TDC that the main injection event can last. You go from 22* past TDC down to 14* at 4200 RPM's.

This is table C7001, Injection Shutoff vs RPM. It's under the Main Injection tab.

Bring these up and you can kill the post injection event and stretch the main injection event.

http://i288.photobucket.com/albums/ll189/Cumminalong/Dohouse%20Diesel%20Pics/EFI%20Live%20Screen%20Shots/MaxInjectionDuration.jpg

I was thinking about this exact table the other day, just hadn't gotten around to trying it yet. Hopefully I can try it tomorrow. Kind of got out of the testing new things for a while, but I'm getting a little more excited about it again. Has the fuel drop off after 2800 RPMs been figured out yet? Also, what rail pressure do you run on stock trucks?

[DoghouseDiesel]

On a stock truck, you want to limit the rail presssure to NO MORE than 165.5 MPa; that's 23,997 psi.

The rail pressure relief valve opens at approx 24,400 psi.

[68showngo]

Nevermind what I said in the above post.. looks like the tune I got already had the last 2 up to 22 and 25. I'm still dropping off a little fuel at 2800. Can't wait to get that fixed.

[CIDRAUGHN]

Has anyone had time to see if bringing up the injection shut off vs. rpm table to 22.0 degrees has made a difference?

[2007 5.9]

Has anyone had time to see if bringing up the injection shut off vs. rpm table to 22.0 degrees has made a difference?

Has made no difference on the 4 trucks I've worked on.

~Les

[DoghouseDiesel]

Les,

Did any of them have decent size cams in them?

Be interesting to see, as the stock cam is pathetic above 2800.

I'm gonna strap mine and a customers back down next Saturday. His is a mild 181/210 cam, mines a 188/220....we'll see if it helps at all with the bigger cams.

[2007 5.9]

Les,

Did any of them have decent size cams in them?

Be interesting to see, as the stock cam is pathetic above 2800.

I'm gonna strap mine and a customers back down next Saturday. His is a mild 181/210 cam, mines a 188/220....we'll see if it helps at all with the bigger cams.

3 of the 4 have 181/210 cams....

~Les

[cumminsDK]

the one i tried it on ran a lot better afterwards, but i changed a lot of other stuff too, inlcuding the boost sensor rescaling which unlike most i changed the voltage axis table to be a straight diagonal line as well. also changed axis tables on all relevant parameters to be linear up to 4600RPM. I'll try changing the injection shutoff table only back to say 10 degrees throughout and see what happens

[LReiff]

Has anyone had time to see if bringing up the injection shut off vs. rpm table to 22.0 degrees has made a difference?

Moving it up past 22 degrees has been detrimental. LOL

[MQ105]

Moving it up past 22 degrees has been detrimental. LOL

How so?

[LReiff]

How so?
Instead of 20 and 14 in the last two cells I made it 25 and 27 respectively. The motor made popping noises and acted alot like the timing was retarded. This only happened once the engine hit the respective rpm.

[MQ105]

Instead of 20 and 14 in the last two cells I made it 25 and 27 respectively. The motor made popping noises and acted alot like the timing was retarded. This only happened once the engine hit the respective rpm.

Was this with a lot of duration?

[AH64ID]

How do the air density adjust tables work into the mix?

[chance cobb]

cool thing i found today while playing around is when you are logging your truck and you click back to the tune tool you can see what the truck is doing in live time on the slected map it just highlights the the map that the cem is using or what ever .

[Scarface]

why on a completely stock file it is a lot higher for that table 42 down too 34 degrees on a bone stock file

[EverydayDiesel]

This is a great thread, keep it going!

[SASDakota]

From 4 almost 5 years ago... lol