Three LBZ tow tune comparison

[Mark Rinker]

I am putting the final details in place for a long trip starting in early March, that will take me from Minnesota to Sarnia, Ontario with boat#1, Chicago to Camarillo, California with boat#2, Dana Point California to Coulton's Point, Maryland with boat#3, possible deadhead or boat from Maryland to Florida Keys, and final return from the Keys with boat#4 back to Minnesota...total miles will be roughly 9200, possibly more depending on the east coast segment to Florida.

The trip will take place over about 5-6 weeks, and will include stopovers in Phoenix, a week of downtime mid-trip at home, and a stopover in the Florida Keys. 1) Loaded, 2) empty with trailer (deadhead), and 3) empty truck (without trailer) miles will be logged and examined. The 2006 K3500 SRW will be used, towing a custom built triple axle transport trailer with 21K# axle capacity. The boats range in size and weight from a 30'-37' LOA, the lightest at roughly 12K# and the heaviest weighing in at about 16K#.

I plan to test three different aftermarket products while underway, trying my best to make meaningful comparisons of their features and functionality. I'll spreadsheet the fuel consumption and take notes on the driveability, shift characterisitics, trans temps, water temps, boost and EGTs observed while underway. My goal is to be as scientific as possible, while realizing that the 'real world' is far from a lab or a dyno test with carefully controlled variables...but hey we tow in the real world, not in a lab, right???


The 'tunes' I plan to take along for the ride:

• Edge Evolution (25002)
• Diablosport Predator (U7186)
• Kennedy Custom ECM - +40hp version

Thermocouple will be installed and Edge used to monitor boost and EGTs. All products are being upgraded to the latest versions available this month, before the test begins. My focus will be on the basic tow/economy settings on all products.

More details, soon!

[DickWells]

Sounds great, Mark. I have an Edge W/Juice Monitor, so I'll be real interested in that one. But, I'm putting my money on the J.K. tune for the best OA performance. Got any kind of pool going, yet? Don't ask me why I'm going with that one. Just a gut feeling. Maybe based on the fact that my first Edge in my GMC didn't do very well, and I've had one shut-down, with bad shifting with the new (replacement) one. Pulled over, hooked up the old Hypertek and recorded the codes and then cleared them. Towed from Ohio all the way to Brownsville without another hitch. Keeping crossed fingers!
Will be watching your road test with bated breath, and thanks for doing this for us.
Dick Wells

[Mark Rinker]

Looking forward to the tests. Its fun to have something to do (besides listen to XM, CDs, the radio, books on tape, etc.) while driving that many miles, as well.

Also, the distance traveled is long enough (sample size) to have meaningful numbers - as ~1000 gallons of fuel will be burned in the process.

[Mark Rinker]

I have been playing with the Predator tunes on both trucks, and installed the Kennedy ECM in the SRW today.

Towed a gooseneck flatbed load of sheet steel weighing ~11K, GCVW north of 26K yesterday with the Predator tow tune installed on the dually. It was too short of a trip to bother with mileage results, but the tune was smooth and held 5th gear well on some fairly steep grades before needing 4th to maintain 65mph.

The key to towing mileage is a tune that will let you tow a reasonable load, at a reasonable speed, without uneccessary downshifting and overrevving into 4th gear. That is where good towing mileage (10-12mpg) comes from, in my experience. I want to be able to tow at 60-65mph, based on load and conditions.

There is definately more HP to the Kennedy tune than the 40hp Predator tow tune, and with an empty truck - it feels like it wants to run! A quick trip through the gears using the paddle shifter is an amazingly effortless romp to 80mph with John's 'tow/economy' tune. John says its the same one on his LBZ. Will be fun to throw ~16K# behind it and see how the Allison reacts to all the new HP and torque.

Kennedy's tune is VIN matched to my SRW, so I'll have to wait for Monday with boat#1 headed from Minneapolis to Sarnia, Ontario - an 800 mile run, to get any real world towing results. My plan is to leave it installed and measure the truck with unloaded trailer mileage from Sarnia to Chicago (350 miles) and the first leg of boat#2 from Chicago to LA.

From there, I'll swap out the Kennedy ECM for stock, and test the Predator and Edge tunes under similar loaded miles. There is 2200 loaded miles from Chicago to LA, so plenty of sample size to have a meaningful result when comparing mileage.

Should be fun...keeping my fingers crossed that the Edge unit shows up tomorrow as tech support promised today...without it can still do mileage and driveability tests, but no EGT/Boost observations.

[Mark Rinker]

Edge unit showed up on time. Installing the pyrometer probe today. Had some fun yesterday playing with the 1/4 mile function built into the Edge Evolution, with Kennedy's economy/tow tune custom ECM in place.

15.2 seconds at 88mph was the best I could muster, with lots of sand still on the country road 'test track' a few miles from my house out in the country... My reaction times suck...

[Mark Rinker]

First leg of the tests will have to be thrown out, as it appears that I got a bad tank of fuel, and the mileage numbers aren't reliable.

So far, running Kennedy's tow/economy tune. With ~14k# boat and trailer, I am seeing

1. 1800 rpms at 65mph cruise - mostly 5th gear, occasionally finds 6th on level pulls. Tow/Haul on.
2. 10# boost nominal, with peaks of 12-14 on hills, max 24
3. 1000-1100 degree egt nominal, peaks of 1200 on hills

Shift characteristiscs are smooth. Pedal response is better than first LBZ tune tested, the bigger power comes much deeper in the throttle so its easier to stay out of it, especially on bumpy roads that create artificial inputs.

[Mark Rinker]

Spent yesterday swapping between Edge and Predator tunes while crossing Nebraska on I-80 in 50-60 degree weather, light winds. Great day for testing - all tests are at 65mph. Estimated GCVW of 23K#.

First reactions:

• The Edge Evolution 'Economy' and 'Tow' tunes run significantly higher EGTs than expected - around 1200F-1250F nominal with our load. Under full acceleration (merging) some black smoke and peak EGTS of over 1400F. Neither tune produces enough torque to get 6th gear, even on flat open Nebraska I-80. Initial mileage results are in low 8mpg range with our load.
• The Predator tunes show lower EGTS of 1000F-1100F towing our load, quiet smooth operation. Full acceleration test yield 1300F EGT, tunes hold 6th on flat surfaces, a little 'shifty' in the hills, where it should hold 5th easily. 65hp performance/economy tune appears to be a better 'tow' tune, than their 'tow' tune...
• Kennedy tune produced a two-tank, 600 mile test of 9.2mpg at 65mph and so far shows the lowest nominal/peak EGTs of all three.

In Fort Morgan, CO this morning. Will see lots of mountainous heavy towing today...

[dieseldummy]

Spent yesterday swapping between Edge and Predator tunes while crossing Nebraska on I-80 in 50-60 degree weather, light winds. Great day for testing - all tests are at 65mph. Estimated GCVW of 23K#.

First reactions:

• The Edge Evolution 'Economy' and 'Tow' tunes run significantly higher EGTs than expected - around 1200F-1250F nominal with our load. Under full acceleration (merging) some black smoke and peak EGTS of over 1400F. Neither tune produces enough torque to get 6th gear, even on flat open Nebraska I-80. Initial mileage results are in low 8mpg range with our load.
• The Predator tunes show lower EGTS of 1000F-1100F towing our load, quiet smooth operation. Full acceleration test yield 1300F EGT, tunes hold 6th on flat surfaces, a little 'shifty' in the hills, where it should hold 5th easily. 65hp performance/economy tune appears to be a better 'tow' tune, than their 'tow' tune...
• Kennedy tune produced a two-tank, 600 mile test of 9.2mpg at 65mph and so far shows the lowest nominal/peak EGTs of all three.

In Fort Morgan, CO this morning. Will see lots of mountainous heavy towing today...

You were in my backyard today! It's not often that I hear anyone on the forums mention Ft. Morgan... Hope you enjoyed the nice non windy day.

[Mark Rinker]

It was really nice weather for towing and testing these tunes...you live in a nice part of the country!

I ended Saturday rolling along western Nebraska and northeastern Colorado with the Predator set on the 65hp performance/economy tune, and soon found myself on I-70W in Denver, about to head into the mountains. Not suprisingly, the first grade resulted in scorching 1500F+ EGTs, and transmission/water temps instantly were headed to the red zones. I pulled into the turnoff for Buffalo Bills gravesite, let the truck idle to cool down, and then switched back to the Predator tow tune...which performed much better on the next set of hills.

It left me wondering - what if some flatlander (like me) ran around empty for months on the 65hp tune, threw the camper on for the Colorado trip in July, and left the tuner in the garage? You'd be headed home to get it, or waiting in a hotel for Federal Express Next Day Air if you were planning to go to Vail pass. The truck would have been absolutely by the side of the road, broken and steaming in less than 10 miles with this setting, and this seemingly 'moderate' tune when on the flats. I have never seen a truck heat up so fast. Chernobyl comes to mind...

Anyway...both the Predator and Edge tow settings performed acceptably in the mountains. Its easy with a heavy foot to see 1400F egts, but equally easy to avoid them with moderation.

Set the alarms on the Edge (great feature) for 1400egt, 220 water temp, 200 transmission temp and accepted the ground speed that would keep the bells from going off. Its difficult/impossible to do a fair test with the variances in altitude, slope, etc so I just kept switching tunes all the way up the hill - including stock - and you might find this surprising, but here is my reaction...

Bone stock is the safest - albeit not the most exciting - but the safest setting for towing heavy in the mountains outside Denver.

Why? Because its as if the trucks were tuned and tested on this grueling set of grades, because you can stick your foot to the floor, set your cruise control, turn up the radio, and never get the truck very far into the 200 degree ranges on transmission or water temps - and ground speed is completely acceptable.

(But - since we are into powering up 6% grades with 15K in tow at 60mph with Eddie Van Halen's 'Eruption' blasting and the cruise control on...)

Kennedy's tune was far and away the winner - in fact I did exactly what was described above, and if the curves weren't so sharp, and so many damn semis to pass with their flashers on in the right hand lane, you could do the whole set of hills, running right with traffic even though you outweight them by 6x-8x...!!! You do need to exercise some caution with the right foot to keep temps down, but no Chernobyl experiences and EGTs are very moderate considering the ground speeds maintained while climbing some serious grades - and were again lower than the other two tunes, often by 50-100 degrees nominal, at the same speeds and grade climbs.

The Edge and Predator tow settings in mountainous driving were almost indistinguishable and would work fine for the more typical 5K-8K camper and recreational loads. You'll find yourself in 4th gear alot where the Kennedy tune would be still chugging along happily in 5th. However, the ground speeds are completely acceptable as are EGTs. Temps were definately higher than you'd experience under stock settings - but nothing off the charts, or crippling to the truck.

More soon...in Utah on last leg to Cali.

[DickWells]

Mark: Do you have separate gauges for EGT and Trans Temp, or do you use the Edge Monitor, or something? You're heavier than I am by a couple of tons, but I have never seen anything above 1300 F while towing uphill past semis at 70-75, and I'm able to stay pretty much in 5th lock-up. Could my Edge Monitor be less accurate than real gauges? Do you trust the stock dash trans temp gauge?
Good work you're doing, and thanks.
Dick Wells

[Mark Rinker]

Mark: Do you have separate gauges for EGT and Trans Temp, or do you use the Edge Monitor, or something? You're heavier than I am by a couple of tons, but I have never seen anything above 1300 F while towing uphill past semis at 70-75, and I'm able to stay pretty much in 5th lock-up. Could my Edge Monitor be less accurate than real gauges? Do you trust the stock dash trans temp gauge?
Good work you're doing, and thanks.
Dick Wells

- Using Edge Evolution for EGT, Boost, Trans Temp, Timing, Fuel rates, etc...

- The information I have seen seems credible. Like EGT probe placement, it could be reading higher or lower than actual, but its consistant for comparison between different tunes, nonetheless.

Don't you get black smoke on acceleration with the Edge tow tune? The EGTs aren't really that bad, even similar when compared to stock settings, but I don't see any reason a perfectly good Duramax should smoke...

A 'couple of tons' is alot, when you consider my gross was 24,750# with boat#2. Like 15% less total weight...

[DickWells]

Yeh, a 4000 lb difference is a lot, for sure. Bound to take a lot more fuel and air to lift it all up a hill.
I don't get any black smoke in level two. Level 3 will give me some, and 4 or 5, well, it's deffinately there. Haven't even tried level 5 with this newer Edge! Allways tow on lev 2.
My engine is an LB7, too. Could be there's a difference there, since the stock engine in the later unit has more grunt, right from the factory?
Thanks for the info. Hope your trip continues to be a good one for you.
Dick

[moss6]

Mark,
Just read your report, excellent; and information that I have not seen elsewhere on a subject/project that I have spent much time on. Your results are very much like what I have found with only a few differences. I have only had the Edge w/attitude and the Kennedy tow tune and not at the same time so my comparisons can't be as close as yours, but much the same conclusions. With the Edge I did not have a separate EGT so results where just what the Attitude showed; but I could see very little difference in EGT's whether set at stock, stage 1 or stage 2....all high and I really think that the Edge somehow corrupted the stock ECM; in fact I'm pretty sure of it because every time I reflashed the ECM to fresh the truck would run much better and then gradually digress again.
As you found I think the Kennedy tune is probably in the neighborhood of 100 degrees cooler. I really wish I had had an EGT guage on the truck stock so I could see how that compared to with the Kennedy tune.
Something I found interesting was how closely related the intake air and EGT's were (going up and coming down had such an obvious correlation). I never did find out where the temperature sensor was located, to me it must be after turbo because of the highs I saw, I believe as high as 190 degrees?? I also recall getting some feed back from a chap, killer something, that swore that temps at the filter box could be as high as 250 degrees....drugs I think. Anyway what are you seeing for intake air temps with the different tunes?
I have found that the best way to keep the EGT's down to an acceptable level and keep the speed up is to let the engine rev. I find under high load if you try to keep RPM's near the torque peak the EGT's will try to get out of hand very quickly and don't come down quick when you lessen the load with a downshift. Whereas if you anticipate and keep the RPM's up before too much rise in the EGT's you can keep them pretty much under control even with very severe grades. For me Raton Pass going South or La Veta pass going West are good examples. Do you find this to be true?
Again great report, I really enjoyed.
Thanks,
Randy

[Mark Rinker]

My engine is an LB7, too. Could be there's a difference there, since the stock engine in the later unit has more grunt, right from the factory?

Dick

That explains it. The LB7 turbo will simply spin up enough boost to burn off the additional fuel. Nothing like the LB7.

The LBZs variable vane turbo has to 'programmatically' respond to the extra fuel rate. I think the black smoke episodes I see with the Edge are simply turbo lag, as the turbo adjusts vane position and trys to get enough air flowing for the new fuel rate.

[Mark Rinker]

Mark,
Anyway what are you seeing for intake air temps with the different tunes?
I have found that the best way to keep the EGT's down to an acceptable level and keep the speed up is to let the engine rev...Do you find this to be true?
Again great report, I really enjoyed.
Thanks,
Randy

• I haven't been watching intake temps, but will start tomorrow and get back to you.
• Agreed. 'Lugging' on grade climbs speeds heat soak - usually starting with water temps climbing. Maybe water pump/fan aren't keeping up at lower RPM?
• Also fan clutch takes way to long to get busy...220F would be great...typically 235 is when I first start getting it to kick in, and by then the tranny 'cooler' is really a tranny 'heater', soaking it up from the high water temps...
• No problem. Its more fun than listening to the same CDs over and over

[Mark Rinker]

Hello from Tucumcari, NM...12 days and 5000 miles into the thrash...sorry for not checking in more frequently, but the last couple of nights I am asleep within 15 minutes of setting down the bags for the night.

Boat#3 from Cali to Maryland is lighter, my gross has dropped from 25,750# to a paltry 22,200# and the behavior of all the tunes shows it. I'll have more mileage numbers to compare as I head out of mountainous driving and have plenty of miles left to compare the three tunes under more reasonable loads.
I have been amusing myself with passing all Ford and Dodge haulers and RV'ers...and waving to all Duramax owners...

(Added later that night...) The Predator tow tune turned in a very respectable two tank, 650 mile sample average of 10.9mpg at 65mph with this 'lighter' boat, across relatively flat New Mexico and Texas panhandle, in moderate 60 degree temps. Cool air really helps the mileage.

[moss6]

Mark,
I'll be interested in seeing your intake temps, they have always surprised me and I would really appreciate someone with knowledge chimming in on where the senor was located.
It appears our loads are many times very similar, our fifth in the neighborhood of 14,000, but I suspect that my wind load is much greater than yours with the pulling the sail effect imposed by the trailer.
Re the Dick Wells comment on the black smoke, in my truck with the Kennedy tune I see a good deal of smoke under hard acceleration unloaded, but I can't say that I have seen much smoke under heavy load pulling the trailer up grades. I try not to accelerate too agressively from a stop when towing for fear that the Allison might not be quite up to the task in stock configuration, so I can't really comment on smoke in that senerio.
As for water, trans, and engine oil high temps; I have taken them out of the equation with the extra cooling mods I made. Now if John could come up with some miracle EGT tune......
Thanks again for your fine report,
Randy

[Mark Rinker]

IAT with Predator appears to be slightly higher than Kennedy tune - as are the EGTs. Nothing major - EGTs are maybe 50-75 degrees higher with the lighter boat. The spread was greater with the heavier boat.

I observed over the last two days IATs in 75-95 degree range, consistantly 20-25 degrees higher than whatever outdoor air temp that I have been driving through. Its hard to make a good comparison unless you are in static outdoor temps, or switching tunes every few hours, which I have not.

For meaningful mileage comparison purposes, I have been doing ~600 mile jaunts before switching tunes. In that distance, weather and temps change cross country. Hope this helps - not exactly scientific.

[Kennedy]

IAT is measured in the air box by the MAF sensor. There is a sedcondary IAT sensor in the intake manifold also, but I haven't seen much info on this one.

Mark is running a somewhat scaled back tune so his EGT's and smoke are much less although like Randy said, the smoke is typically just when you "whack it" in a turbo lag condition.

[moss6]

Mark,
I'd be interested in seeing what your IAT is when the EGT's are high during a long hard pull, should you get a chance. I stated that I had seen 190??, thinking back it may not have been that high but sure it was well above 160 degrees. It's in one of my reports, I think on this site.

John,
Curious there being two sensors, but the only way that it would make sense to see the numbers I have seen. I wonder if there is any ECM interaction at that one other than being a monitor. The edge must read the one at the intake.
Think I'll take my scanner with me next time and see what it reads when things get severe.

Randy