I am tuning a friends 04 dirtymax. I have followed the tutorial for the timing calculator, although I think I am doing 50% when most seem to recommend 20%, but I don't know how to change for 20 instead of 50. What other changes should I make? Also how do I change the speedo for taller tires? In my gas trucks I just plug in the tire hieght and thats it. That option doesn't seem to appear for this truck. Thanks, Chase.
1stchangesdirtymax.hpt
So after reading a lot more I have actually began to understand a lot of this much better. The 50% is regarding timing and the 20% is regarding boost/fuel.
I have added the 50% timing if I have done it right. I am thinking I want to do a 10/10 tune to start and see how things go. I am going to remove TM as well. Please let me know what else I can improve.
After additional reading I have added 10% more boost if I am not missing anything. I will attatch the most recent version.
Thanks, Chase.
what changes do I need to make to the Pulse width tables?
Okay I have removed the speed limiter, done the timing calculator at 50%, added 10% boost, and now I am trying to figure out what to do about the Pulse width to add 10% more fuel. I understand how to add the fuel, but not which parts of the table where I need to add. Also I am not sure how to correct the speedo for the 35's on the truck. Thanks, Chase.
Bump still looking for some help on this one...
Check out this thread...just ignore the stuff that doesn't apply to your truck.
Roger Ramjet
The LB7 turbo boost needs to be adjusted manually, Kennedy Diesel has adjustable boost valves.
Does your friend have a pyro guage?
To adjust for different tire size you have to take some measurements and do some math.
First we need to get a measurement of the circumference of the tire.
I like to do it while on the truck. get the tire at the correct pressure and at operating temperature, then on flat level pavement mark the pavement next to the centerline of the tire and continue the mark up onto the side wall of the tire.
Roll the tire one full revolution, make a new mark from the tire where you place first mark and continue it down onto the pavement.
Now measure the distance from the first mark on pavement to the second mark on the pavement, this is your tire roll-out.
Now some math.
One mile is equal to 63,360 inches, divide 63,360 by your tire roll-out. This is how many revolutions the tire makes in one mile.
Now start VCM Editor, open the file you wish to modify, the go Speedo/General you should see the speedometer settings. the boxes to modify(see attachment), are the VSS Tire Revs per Dist-Trans is where you put your first calculation.
Now for next calculations, take your tire revs per value and multiply it by final drive ratio. then multiply this by the Rev-Trans value (40 in most cases), put that value in the VSS Pulses per Mile box. Round the value if needed.
This should be very close you can double check with GPS.
Last edited by apex2112; 04-29-2013 at 07:26 PM.
I looked at the tune you have attached and I don't see any modification to the fuel tables?
The best way to learn is to download some other LB7 tunes from the repository and compare them to your stock tune. See what other people are changing and by how much. LB7 needs a boost controller, as it doesn't have a variable geometry turbo.
2006 LBZ Duramax
5" Magnaflow turbo-back
EGR blocked
HP Tuned by yours truly
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