LBZ: Tow Tune

[petestoy]

I have uploaded a tow tune to the tune library that i have been working on for a while and would like some help perfecting. The truck runs good but, a bit more smoke than I would like, so I started adding boost to try and reduce the smoke. I will be towing a 29 foot travel trailer through the rockies in July so would like to have it perfected by then. So if someone could let me know if I am headed in the right direction it would be appreciated.

Here are my questions:
1. when towing with this tune up a big hill heavy(around 10K) she billows black smoke. I have increase both pressure and pulse width so obviously need more air, problem is the truck does not downshift out of 6th so I am at about 1625rpm and comanding 180MPa an 2013microseconds. How much boost can I make at this rpm?

2. what is low altidude, med and high?

3. I don't have a pyro guage so I am not sure what egts are. What is the guideline for fuel limit for exceeding egts?

Thats it for now any help would be apprecaited.

http://www.duramaxdiesels.com/forum/showthread.php?t=32350

 

[JoshH]

You should be able to safely run between 15 and 20 lbs of boost at that RPM.

Low/Med/High altitude is defined in table B0202.

At the pulse width you're running, I would imagine your EGTs are probably running pretty warm going up hill with a big load.

I made a few changes to your tune which is attached to this post.

 

[petestoy]

Thanks Josh, i guess i should have been more clear in my questions, Low is sea level, medium is? 5000ft? high 10000ft?

 

[JoshH]

It is based on barometric pressure. If you look at table B0202 you should see how is uses the multipliers in that table to scale between the different altitude tables for different barometric pressures. If you want to know the actual altitudes for the barometric pressure, you can probably find a chart that converts different barometric pressures to different altitudes, but keep in mind that barometric pressure changes slightly with the weather.

 

[petestoy]

Back from Trip

Finally got back from our trip out west and just wanted to update everybody regarding this tune. First of all tune ran great when empty, loaded it smoked a fair bit at low altitude, and increased from there! I kept adding boost to try and minimize the smoke and was relatively successful, but it still needs boost in the mid and high altitude boost settings. Unfortunately we left those altitudes before I could get it under control. The other thing I noticed was the engine temp climbed to 230 on some big long uphill pulls (8% grade starting at about 5200 feet and ending at around 7600 feet). Granted I tipped the scales at almost 19000lbs. Hopefully the boost helps or else I will have to pullout some fuel. On a good note I averaged around 12 to 14mpg for the trip (10262Km) and now I understand the altitude multipliers much better.
Thanks for the help guys!

I have attached the modded tune if some one wants to add some input.