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Tuning and Programming the 6.5

Matt Bachand

Matt Bachand

Depends on the 6.5
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Was brought up recently that this deserves its own thread, and I agree.

I will be 'tuning' my 6.5 this summer and was going towards the heath towing tune since my truck is heavy and always will be.

I believe this one is the +40hp tune vs the +80tune.

I'd like to talk about the difference tunes, and the software / programming of each. For my knowledge and for that of others.

I also plan on putting 235/85's on, instead of my 225/75 gearing me down roughly 7%, resulting in tamer 4.10's and better highway RPM (lower).

Is that something he would incorporate into the tune to correct shift rates and TCC Lockup?
 
You will need to have the speed buffer reflashed for the different size tires. Your speedometer and ecm will read the wrong speed.Or summit racing sells a speed correcter box that is adjustable for aprox.$235.
The shift points and firmness can be changed in a reflashed ecm. I'm not shure if bill's does that or not.
 
Bill's flash most definitely changes the shift properties. The shift points are changed to take advantage of the 6.5 power band and firmness is dramatically improved without being too firm. The best analogy I can give is it seems to pull like an electric motor; just a steady and consistent pull from idle.
 
Looks like you could get a VSS buffer from a 3.73 geared truck and it would work correctly since your effective final ratio will be right about that using the taller tires.
 
buddy said:
Looks like you could get a VSS buffer from a 3.73 geared truck and it would work correctly since your effective final ratio will be right about that using the taller tires.
Click to expand...


The buffer is the same for all gears Converts the analog signal,to digital that drives the speedo. The difference is the drive gear in the trans, that is easily replaced.
 
Slim Shady said:
The buffer is the same for all gears Converts the analog signal,to digital that drives the speedo. The difference is the drive gear in the trans, that is easily replaced.
Click to expand...

Thats the way my old 700R4 worked with a gear in the tranny, but the manual for these electronic trannys says the buffer module is matched to final drive ratio, and specifically says if changing the drive ratio the buffer module must be updated.
 
There's a thread on one of the other forums about how to change the VSS jumpers. The VSS is just a circuit board with a bunch of jumpers set for a particular gear, wheel, and tire combination. You can even pull off all the jumpers and replace them with two sets of 8 dip switches so you can change the jumpers easier if you swap tires a lot. Can't find any pictures or links off hand right now.
 
http://www.tbichips.com/drac/

All of the 6.5's used the VSSB/DRAC on up to 00 or 01 whereas gassers did away with it in 96 and let the PCM do it from there on. There not hard to change if you can solder, and the 2 dip switches are fairly cheap. this site also gives you the chart for configuring the jumpers. All of the 4L80E's either have the 40 tooth tone ring in them, or the transfer case has the 40 tooth tone ring.
 
THEFERMANATOR said:
http://www.tbichips.com/drac/

All of the 6.5's used the VSSB/DRAC on up to 00 or 01 whereas gassers did away with it in 96 and let the PCM do it from there on. There not hard to change if you can solder, and the 2 dip switches are fairly cheap. this site also gives you the chart for configuring the jumpers. All of the 4L80E's either have the 40 tooth tone ring in them, or the transfer case has the 40 tooth tone ring.
Click to expand...

Great info. I'll dig into that deeper once I have my new skins on. Which I dont look forward too... Gotta love DRW, argh, only thing worse then shelling out 4 new skins, is having to buy 6 of em :)
 
since I'm not changing tire sizes anymore, I just removed and resoldered jumpers on the board, using that chart I got within 1 mph of on the money, and it cost me nothing.:D-another example of forums saving me thousands so far.
 
My 94 truck has what they call the DRAC, not sure if it was stock, it was built in late 93. I guess the DRAC and VSSB are interchangeable though.
 
buddy said:
My 94 truck has what they call the DRAC, not sure if it was stock, it was built in late 93. I guess the DRAC and VSSB are interchangeable though.
Click to expand...

One and the same basically. The VSSB has 2 sets of jumpers whereas the DRAC has one set. The second set is in the exact opposite of the first ones to help cancel out RF noise.
 
OK, back to the tuning...

Here's the deal - there are three dealers to talk to about chips/reflashes - there actually are more than three, but these are the only ones worth mentioning:

Kennedy Diesel
Heath Diesel
Wester's Garage

If you're in Canada - so is Wester's.

You'll absolutely be happy with any of these guys.

On edit: My advice is to search around on this site and look at previous discussions, PM people, and talk to all three vendors and make up your mind based on that. I have a personal preference, but any of these guys will be able to give you a good product. Unless you try all three tunes, back-to-back under the same conditions, you'd never know the difference. Even then, you'd really have to take some exact measurements. I did have the opportunity to do that with 2 of the vendors - very minimal difference - almost not worth mentioning.
 
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Turbine Doc said:
when comparing tunes 80 vs 40 hp need to know where they are measuring the HP at, flywheel or rear wheel, it makes a difference
Click to expand...

Indeed. I just used the HP ratings for reference as to which program I was referring too. I don't expext an instant 80 or even 40 HP. What I'm most interested in, is optimizing fuel/power and shift points.
 
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