Tune advice and opinions on LB7

[matthew4201]

Hi,

I have been reading and looking at tunes, learning what I can about tuning diesels. I started off with the Mcrat 20/20 then modified it from looking at some other tunes. I attached my stock and modded tune. I would like opinions/advice if I have gone at it wrong or any red flags.

One of the things I haven't been able to find much info on is timing. I read that you want more timing to allow as much fuel BTDC without going too far and spiking cylinder pressure. Hopefully I'm on the right track by copying some other tunes.

I don't have a boost or egt gauge right now, but they will be added shortly. I do have a straight pipe 4" exhaust, but otherwise stock. I am shooting for something I can tow a moderate trailer with, and as much MPG as I can manage.

Thanks in advance for taking a look,
Matt

[mecanicman]

Hi Matt,
In looking at your tune, you have added fuel all the way accross the board including idle. You have also done something funky with your injection timing. If I had to guess, I would say it runs rough at an idle, shakes the truck a bit? It is best to leave the idle portions alone, as well as lower rpm areas. You have also not added any extra air(boost) to work with your extra fuel. I have attached a LB7 tune that I have done. It makes good power, and on the last 1200km road trip got 24 mpg(im in Canada, so thats imperial gallons) Timing on this one was calculated using a 50/50 timing calculator, which seems to work quite well(message me if you want a copy of calculator, works in excel).
The fueling in this tune is progressive, 10, 20, and 30% increases from left to right. Boost is increased in the same fashion except the lb7 is hard coded to 255, so that is where it maxes out. If you have a ppe boost valve or similar you must take that into account. This tune revs slightly higher to 3400 rpm in the first 4 gears. Transmission shifting is aggressive, I do not suggest a straight copy of it, do it slowly and tailor to your likes. Use at your own risk, and while it does make a great tow tune, it has enough power to take out the trans if you try to use it 5th gear!

[matthew4201]

Thx for looking at things. I'm at work so I will have to wait until I get home to look at your tune. Right now I haven't noticed mine idling funny, but I know that my friends truck(LLY) does. The timing I just copied from another tune. I see what you are saying about the idle parts of the tables. On the boost, I didn't know the LB7 controlled boost. I thought the wastegate just opened at a certain pressure? What does the desired boost do on the LB7?

I will do some more looking and reply again when I get home. Any other thought?

[matthew4201]

Hmm, I just tried to look at your tune and it said the index was outside the bounds of the array?

[mecanicman]

Means I am running a newer version of hpt then you. You will have to email support and ask for the latest beta to be able to open it.

[matthew4201]

Ok i finally got the newest version and looked at your tune. One question I have is it would seem the higher advance in the bottom right would be limited by the max timing table no? I got my specs plugged in and saw what you were saying about my timing being all over the place. I read one thread that said 55/45 was better for economy and 45/55 was better for power. Would 60% btdc or more have a fair increase in mpg? I know it would increase cylinder pressure, I just dont know how much is too much.

Also Im not seeing the increased boost or transmission settings you were referring to?

[mecanicman]

Yes, you are right about the max timing table. I have changed that in a newer version, posted the wrong one. I will find the newest version and post it for you. My bad.

[mecanicman]

Here is the file I ment to post, sorry about that. I believe you should find all of the items I described in here.

[matthew4201]

Ok I finally got a chance to sit down and play with that calculator. Awesome tool. I changed the timing around as well as the PW, backed them both down to stock at idle. I uped the max torque and desired boost as well.

I would like to try out some of your transmission settings, but I think I will see how this goes on the engine first. Have you messed with the defueling on shifts at all? On some shifts it seems to take forever before it finally goes. Im wondering if shortening the shift times like you did would help that?

Thanks for all the help so far!
Matt

I added the tune if you care to look it over

[mecanicman]

Yes, I have played with the defueling. All of the mods made under Engine, Torque Management, General and/or Engine Torque relate to the defueling. I enjoy the trans settings, makes it drive/shift much more like a gasoline engine. Works well when truck is used as commuter, fun for driving around town. Would not recomend towing with the trans tune, the potential is there to do some damage.