`06 LBZ improvement, MPG and power [Archive]

pete m

01-17-2010, 10:11

I just sold off my `05 LLY truck that had an Edge EZ controller installed, was absolutely awesome with power, on level 1 it added 1 MPG, on 2 it added 2 MPG, and had too much actual power for what I needed, I never tried level 3. I added this only to increase mileage and help with a little bottom end power with daily driving. It got 18+ on the highway, and was a dually.
So I now have a 2500 LBZ truck, i use this for daily driving and also to tow a 10,000 lb. race car trailer, i am not interested in making the truck a race truck, i have a 1000hp dragster I race, just looking for more MPG and a little more bottom end power when daily driving, as this truck still lacks eventhough its a much bigger engine on paper compared to what I just sold, truck currently gets 13 to 15 in city driving, on a 500 mile trip on the highway driving 60 to 65 it got as high as 17 on the DIC, hand cal. to just under 18.
I have looked around and can not seem to find a "plug-in" unit like the EZ that I had that fits this truck, so I am asking for advice on what is available in a small boost in power and is the best bang for your buck in a performance enhancer. The one thing I did NOT like about the Edge unit I had was when you were towing, if you put your foot into the throttle close to 1/2 way down while accelerating, it would suddenly take off like you hit the NOS button with power, would start pouring out tons of black smoke and seemed to have too much power, I am looking for something much more smoother in the power band and not cause any damage to the engine or trans.
What do you know about different units, how have they worked for you, and whats the cost?, appreciate any help.

Mark Rinker

01-17-2010, 11:53

Welcome aboard!

I love the 2006 Duramax package. Think of it as a 'factory chipped' LLY Duramax. With that in mind, realize that in stock trim, you are running closer to the ragged edge of what the stock Allison torque converter can hang onto.

The stock variable-vane turbo is nearly bullet-proof mechanically, but is also the first componant to overheat when fuel rates are increased over stock. In hot, extended, and/or mountainous towing conditions, a heat soak begins that can cause the entire cooling system to reach its 'tipping point', thermally.

Have fun - with your knowledge of what it takes to make 1000hp and keep parts happy - you'll have no problem appreciating what happens when you push stock drivetrain componants under varying loads, power levels, etc. My opinion is that Edge tunes are 'smokey' and made for street racing, or light towing. Kennedy diesel makes a good ECM based tune for daily drivers, that delivers the mileage while making 'big block' feeling power.

My overall heavy towing (GCWV >18K#) observation, with 100K+ total towing miles on two 2006 trucks is to run it bone stock (and with your foot to the floor if you want) - or chip it slightly, and then be conservative with your right foot, who else you let drive the truck, and keep an eye on the trans temp and water temp gauges.

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=33987

Have fun!

pete m

01-17-2010, 18:26

Mark, thanks for all the input. I was hoping this would have a little more kick daily driving, I have not towed with it yet.
I was reading where this engine/trans. is a little different from the LLY, the torque converter was supposed to be "beefed up" from the `05, to handle the extra power and the engine is 50HP and 60 lbs. torque more than what I had right?, but this feels about the same as my `05 did when it was stock, when I added the Edge, even on level 1 it ran like a raped ape", level 2 was too much as I said, I am a little dissapointed in the way this LBZ runs and the mileage.
I hear what you are saying about having too much added power stressing the stock parts to their limit. My truck is bone stock, was purchased from the original owner, I know it never did any heavy towing, as there was no brake controller hooked up, and the factory harness for it was still in the glove box, but, GM did just replace the turbo under warranty this year. It went in for a poor performance service call, and thats what they replaced along with re-flashing the glow plug system, so without any heavy towing, not sure why they had to replace the turbo.

As a side note, i was under the hood on the truck today, and saw that the air filter plugged up indicator popped out, so I looked at the air filter and it was filthy, so I bought a K&N for it, $75 later I installed it and reset the indicator, not sure till I drive it tomorrow if that will make any difference, I figured if it was really bad it would have thrown some sort of code or message on the DIC, which it did not.

Where can i get some info on a Kennedy tune as you mentioned, is this a programmer type like the Diablo or Edge?

Do you have any family in the WNY area?, I used to work with a father and 2 sons named Rinker, Dale, Mark and Mitch.

Mark Rinker

01-17-2010, 20:11

www.kennedydiesel.com (http://www.kennedydiesel.com)

I think the power you have with the LBZ should be similar to the LLY with a 'level 1' tune...however the power is more linear, and found deeper into the pedal.

The Kennedy tune has the most 'seat of the pants' kick and the extra timing makes the Duramax SOUND different than any other tune on the market. It might be a bit much for heavy, constant towing - but that can be regulated with your right foot.

Have fun...no relatives known in NY, although most of the family tree hails from settlers in VA's Shenandoah Valley.

JohnC

01-17-2010, 20:16

Early 2006 were called LLY but were mechanically the same as the later LBZ. the '06 LLY power was the same as the '05 LLY. Could this be what you actually have?

Mechanically it is an LBZ and should not be plagued with the LLY cooling issues of the earlier years.

The stock [Donaldson] air filter is very good. The K&N lets in enough grit to scare me...

DieselDavy

01-18-2010, 07:03

Pete,
The first thing I would do it so remove that K&N and replace it with an OEM type unit.
Then after getting some baseline numbers (running a few tanks of fuel through it) I'd call John at Kennedy Diesel and have him hook you up!
Good luck and have fun!
Dave

pete m

01-18-2010, 16:14

The truck is definitely an LBZ, has a "D" in the vin., not #2 like my LLY had.

The air filter I took out was also a K&N, this is just the cone insert inside the stock housing, not the complete system. Truck does seem to have a little more bottom end with the new filter.

Looking for a very mild system to add if anything for more MPG and bottom end power when city driving, unless I just have to start putting my foot into it more, was never used to driving like that, this is my 3rd. Duramax after owning 1 powerstroke, and I never had any of them on the floor. I got spoiled owning (2) 8.1 liter big blocks before the Duramax trucks, the power they had was wild, so was the lack of fuel economy, so when I started driving more I was forced to get rid of them, got 7 towing and 9 to 10 not, was spending $120 a week in gas to get to work.

From what I have read, the Superchips is about the mildest system available, only adding about 40 HP in the tow mode, any thoughts????.

Mark Rinker

01-18-2010, 18:38

>>> From what I have read, the Superchips is about the mildest system available, only adding about 40 HP in the tow mode, any thoughts? >>>

Based on what you've said? Drive it with a heavier foot for 30 days, before you spend any money on tuners. Seriously.

pete m

01-18-2010, 19:00

How can a "heavier foot" help fuel mileage?

I guess I should wait 3 months till the snow melts and we start racing again, and then I can hook up the trailer and see how well it tows and then make a decision.

My main concern was trying to get to the 18+ mpg range, what about the Kennedy "boost stick", or is that also something I don't want when towing?

Mark Rinker

01-18-2010, 19:35

Waiting would get you back into non-winterized fuel as well - and improve mileage.

Its hard to find more mileage while adding fuel, unless there is something basically wrong with the factory timing, fuel rates, and boost levels. The factory '06 tune is pretty good...they basically gave us a 'Level 1' tune from the factory.

Not familiar with boost stick. Never tested it - the custom Kennedy tune had more boost dialed in programmatically. I think you might find what you are looking for with Kennedy's LBZ economy/tow tune, from what I am reading. Better power down low, good unloaded fuel economy, possibly even more than factory.

In any case, you should always have the ability to return to factory tuning by carrying the tuner, stock ECM, etc. in case you encounter a situation where more fuel rate, timing, and boost is NOT to your engine's benefit.

Mark Rinker

01-18-2010, 19:50

>>>and then I can hook up the trailer and see how well it tows and then make a decision. <<<

Remember, more load behind the truck = more fuel rate = more EGTs = more boost = MORE POWER.

Loaded, stock tests are certainly in order! The stock LBZ took me over 60K towing miles last year, coast to coast, north to south, with average GCVW weights of ~20-22K#...most of the boats I haul are 12-14K# with 3K# trailer, so I am careful about pushing the turbo too hard, especially in the summer heat and anywhere mountainous.

If you expect a flatland mix of daily driving and towing at max of ~18K# GCVW, JK's tune, or similar 40-60hp tow tunes will fill the bill.

pete m

01-18-2010, 20:10

I believe the truck weight is about 5600, crew cab 2500 long bed 4X4, trailer is just under 10K loaded, so it would definitely be under 18K, I am looking to do a mix of both types of driving, mostly flat land, and I drive with a VERY light foot, as i said, I don't know where the floor board is under the gas pedal, and really don't want to. I was mostly afraid of the LLY with Edge because it really took off at 1/2 throttle, started blowing a LOT of black smoke and really started pulling hard, with 10K behind it, I was afraid i would damage the engine or trans eventhough it was supposed to be only adding 50HP and 100 lbs. Torque.

I did read about one of the tuners that was supposed to be very mild and smooth in power, unlike the Edge.

What is the cost of the Kennedy economy tune you mentioned?.

Mark Rinker

01-18-2010, 21:18

Call JK @ www.kennedydiesel.com (http://www.kennedydiesel.com) for prices. I think you'll see same or better mileage during unloaded driving, with LOTS more power, and a noticably rumbly, aggressive feeling/sounding torque curve. Definately the most fun to drive of all the LBZ tunes I have tested.

The Predator LBZ tow tune is moderate and well mannered, the tuner gives ability to read/clear codes. Don't expect to see any mileage increases, loaded or unloaded. I run the Edge Evolution on my dash for gauges, monitoring up to 4 vehicle parameters at once, through the OBD-II port. (Find one used for cheap on Ebay and you have a mess of data for a few hundred bucks, installed in about an hour, mostly drilling and installing the EGT probe.)

Right now, JK's custom tune ECM is under the back seat, waiting for the next empty, unloaded trip somewhere or the next county fair truck pull. The Predator is on the back seat, ready to read codes. The stock ECM has been in place more often than not, for the last 40K or so.

Thats where I have ended up, with what I do.

madmatt

01-20-2010, 05:06

EdHale

01-20-2010, 17:08

I had mine weighed with full fuel (original 26 gallon tank) and absolutely nothing in it and it weighed exactly 7,000 lbs. I can add 156 lbs more to that now with the new Titan 52 gallon tank.

pete m

01-20-2010, 19:19

Well even if it does weigh 7000, it will still be under 18,000 total. I had a CC 4X4 Duramax dually that had 9200 lbs. stamped on the title , before that I had 2500 Duramax, CC, short bed 4X4 and that title said 5500, this is the same truck as that except for a long bed so i figured another 100 lbs, don't have the title yet so i don't know for sure.

What about some more input on a mild tuner for this, watching a Bully Dog power pup on eBay, says it has a mild 45HP tow tune, what about this one?.

Is it safer to change out the ECM instead of adding a tuner, truck still has 9000 miles on the engine warranty, don't really want to use it, but don't want a rejection if i have to take it in, on a 2006 does a tuner leave any traces of install?.

Appreciate the advice, thanks!.

DieselDavy

01-21-2010, 07:28

Pete,
I think the reason you are getting people telling you to go with the ECM swap is that your ECM won't contain any traces of mods that might have been installed, thus voiding your warranty. It's hard to been John's (Kennedy) tune. I think he custom tunes as well based on you individual needs.
Have fun!
Dave

Kennedy

01-27-2010, 09:04

I would suggest starting with the ECM programming and progress from there. With the LBZ I would leave the intake stock. A 4" full exhaust is always a benefit and will only help, but is not necessary. I make no promises on MPG, BUT I repeatedly receive reports of best ever MPG and topping 20+ is quite common IF you behave.

My LBZ is my least modified truck (ECM and that is it) yet I find the powertrain package to be my favorite to drive. I just wish it was a 3500SRW like my 05 so I could keep it...

havenopower

01-30-2010, 16:09

Kennedy, what would it cost for a mpg helper tune for me LBZ i only get 12 mpg. I have a efi live tuner and guy from socal diesel gave me like a 50hp tune. i see no difference from stock to now on any thing.. And on my 04 i run the edge on 2 and ppe's accelerator on 8, lots of smoke, do you think it is necessary to do something with that ecm on this one.

Kennedy

02-01-2010, 14:24

pete m

02-05-2010, 19:36

OK guys, here's a question. I didn't take Mark's advice about waiting to buy a tuner. I was not happy with the way the truck ran, this is my 3rd Duramax after owning a 7.3 Ford. This has the least miles on it of any, and has never towed anything heavy, brake control pig tail not yet installed. This truck has about the same power as my LLY had when it was stock, after I installed the Edge EZ on the LLY it ran like a raped ape, on level 1 it was wild, on level 2 I was afraid it would hurt something, never tried level 3. I thought this LBZ would have more power and better fuel mileage stock over the LLY, it did not. I was even thinking of selling the truck, was just at a dealer, had a complete turbo replacement done under warranty for a poor performance claim. There is nothing wrong with it now, just seems to lack the power that the LLY had.
I bought (2) units, a Superchips Flashpaq, and Bullydog Powerpup. I checked them both for any available updates online, installed the Superchips unit on the lowest Tow power level, WOW!. Was very impressed with the total increase in driveability with a LOT more power thru-out the entire rpm range, not just when your foots in it.
Here's my question, the truck sounds totally different, is louder at idle, has a LOT more crackle, has immediate throttle response, this is supposed to be only 44 HP and 80 lbs. torque, is this too much for this engine ?, this has quite a bit more power than my LLY had even on level 2, I really enjoy driving it, but don't want to damage the engine, especially when i start towing the race car trailer in a few months. This really waked this motor up, just hope its not too much, I put my LLY into "limp" mode once, don't want to do it to this one, so why is it louder ?, timing?
I will try the Powerpup after a few tanks of fuel,and then decide which one I will keep, so far this one has a ton of power, and according to the DIC, is getting a lot better fuel mileage, about 2+ just in city, have not run it on the thruway, but when I got up to 55 for about a 4 mile stretch, it got over 19, well, what do you think ?????????????.

EdHale

02-06-2010, 04:10

Mine always gets 19+ on the highway and has plenty of power for me even when towing. If I have any engine/trans problems between now and 100,000 miles I don't have to worry about paying for it.

Bone stock and staying that way.

pete m

02-06-2010, 09:03

Your trans is only covered 3 years /36,000, only the diesel is good to 100K. Mine is still covered, and the program will NOT void a warranty claim.
I have heard of guys only getting 12 with an LBZ, I was getting 16+ in city and 17 on the highway, stock, with winter fuel, in 10 degree temps, definitely not the perfect fuel mileage conditions. I am sure with this program installed it will get 20 on the highway with no load even with winter fuel.

Kennedy

02-06-2010, 09:26

This really waked this motor up, just hope its not too much, I put my LLY into "limp" mode once, don't want to do it to this one, so why is it louder ?, timing?
I will try the Powerpup after a few tanks of fuel,and then decide which one I will keep, so far this one has a ton of power, and according to the DIC, is getting a lot better fuel mileage, about 2+ just in city, have not run it on the thruway, but when I got up to 55 for about a 4 mile stretch, it got over 19, well, what do you think ?????????????.

Teh sound is likely timing. I have not tried that one yet so I cannot comment on safe or not, but will say the LBZ pistons cannot take a lot.

As for the MPG, the first table that these off the shelf tuners go to is the injection pulse. By altering these tables you are slipping fuel into the engine without the knowledge of the ECM. This will result in a skewed DIC calibration. Gallons vs miles is the only way to calculate MPG with one of these tuners.

As for warranty, ANY evidence of ANY tuner will give the dealer grounds to dismiss warranty claims. I'm not saying that this is right or that it will definitely happen, but it's just the way it is.

DmaxMaverick

02-06-2010, 09:49

Nothing you do to your truck will "void" your warranty. Nothing. If you modify your truck, and that modification can be determined, or believed, by the dealer to be a contributing factor to a warranty claim, they will deny the claim. If your dealer is OK with electronic power mods, and will honor engine warranty claims, knowing or believing a power mod has been used, you have a unique dealer. How they are putting this over on GM is curious, as their policy clearly states otherwise. You can't hide it from any competent dealer tech. A replacement PCM, perhaps, but even then not 100%.

If you are using a plugin module and relying on DIC mileage calculations, you may be in for a bit of a surprise, and not a good one. The modules "lie" to the PCM to give you extra power (fuel). Part of that "lie" requires the PCM to "lie" to you about your fuel economy. The modules you are using are not an exception. Driving habits generally determine the degree of variance with the mileage, and will usually be a full swing in the opposite direction of what the DIC indicates. In the end, hand calculation over several (dozens) tankfuls is the only reliable method of economy calculation. However, a completely stock vehicle will be generally accurate. More refined uploader programmers and PCM updates can, and usually do, retain the PCM fuel map accuracy.

2006 began the 100K mile powertrain warranty (actually 2007, retroactive to some 2006 models). Depending on build date, a 2006 build truck may, in fact, be covered by the 100K mile powertrain warranty. The tranny, last I checked, was part of the powertrain. GM has always, since 1978, warrantied Diesel engines for 100K miles. Nothing new there.

pete m

02-06-2010, 10:10

I bought my truck from a big GM dealer in Indy, he ran the vin, and told me there is warranty left on the LBZ engine to 100K, and that the rest of the truck ran out at 36K, thats why I posted that.
With the truck stock, I was within 1/2 a MPG difference over a 500 mile range on every tank between the DIC and real calc. I have only driven 150 miles with this program installed, so have not had a chance to hand calc. the mileage, with the extra power it seems to have, I would expect it to be higher due to the fact that my foot is not into the throttle as much.
I am not looking for huge power from my truck to race it, as i stated earlier, I have (2) drag cars I race, all I use the truck for is daily driving and to tow a 10,000 lb. trailer, so I wanted more bottom end power for daily driving, and better fuel mileage if possible, since i was getting much better with my LLY trucks, had (2) of them. This timing issue worries me, since I can't back this tuner down any more, its on the lowest level they offer. I have not tried to tow anything yet either stock or otherwise with this truck yet.

DmaxMaverick

02-06-2010, 12:59

Less foot-feed does not equate to less fuel with the electronic mods. Like said above, they lie to the PCM. The accelerator pedal is electronic, and has NO direct correlation to actual throttle position or fueling. This is why you had the experience with the 1/2 throttle take-off. Earlier fuel is earlier boost, resulting in earlier power. You should never have any significant amount of black smoke with any of the available power mods at low settings. If you do, something is wrong (like an overdue air filter or poorly positioned or dirty MAF). Most of them produce very little smoke, even at moderate to higher levels. More power is more fuel. There's no way around that fact. If you are using more power, you are using more fuel. The key is using (and not using) that extra fuel at the right time. Also, spending money on the mods to get better fuel economy will rarely ever return your investment. We should always consider any economy improvement a bonus to the extra power. If you get it, great. If not, then it's just "normal".

pete m

02-06-2010, 19:57

I understand what you are saying about throttle position, and I did not like the way the other truck took off at 1/2 throttle with the Edge EZ, thats why I got rid of it. I thought going to the LBZ would have the same or more power with no mods, and get better fuel economy. The EZ had a LOT of smoke at even less than 1/2 throttle when towing, used to cover the front of the trailer with black soot.
As I said, I have not towed yet with this truck, there is almost no smoke with it stock, even at 3/4 throttle, after the Superchips was installed there still is almost no smoke, I just got home from driving it, and was running up a thruway ramp to merge into traffic and I had it at about 1/2 throttle and there was only a little smoke, no where near where the Edge would have done, and the power increase was very smooth and controlled, not an instant burst of power, even up to 70 mph.
As far a fooling the DIC, unless it also makes my fuel gauge read wrong, it is running pretty close from what I can tell, before install, if it said I used 30 gal., when I filled it up it would be within .2 of a gallon everytime, right now its saying i used 15.5 gals. and is about a needle or more above 1/2 a tank. I will have to fill up when it gets lower and hand calc. to know for sure, so far this unit seems very easy to drive, will run a few tanks of fuel thru to get some numbers and then try the Bullydog and compare.
Still would like to know why this does not get the mileage some say they get, although, I have also seen some post they only get 12, I would guess the truth lies somewhere in between.
When I start racing I will try towing stock and then with both on the tow setting and compare.

Mark Rinker

02-07-2010, 15:54

>>>You should never have any significant amount of black smoke with any of the available power mods at low settings. If you do, something is wrong (like an overdue air filter or poorly positioned or dirty MAF). >>>

Edge tunes are the 'smokiest' when compared to other aftermarket tunes, in my experience - even on low settings. Injection timing in relation to fuel rates, variable vane turbo settings, etc. all play into the characterisitics of how a tune drives and performs.

One thing that is nice about the Edge Monitor is the ability to monitor up to four engine parameters at once, digitally on your dash. My suggestion is to monitor these four, then test as many LBZ tunes (including stock) as you can.

EGT
IAT (...best early indicator when turbo is overheating and heat soak beginnning)
Timing
BoostAlso trans temps and water temps...with stock gauges.

Too bad there isn't a OIL TEMP gauge or monitor readily available...or a light that says 'YOU ARE SMOKING YOUR TORQUE CONVERTER, PAL..." ;)

pete m

02-07-2010, 21:12

Hi again Mark, you have any experience with either of the tuners I bought?, I am currently running the Superchips, so far seems really smooth and driveable, just do not like the engine sounding louder at idle, especially when i first start it when its cold and it ramps up to 1200 with the "elevated idle" setting, other than that seems nice, and has almost no smoke at all even when you stand on it a little.

Mark Rinker

02-07-2010, 22:24

No experience with either of the units you have.

pete m

02-15-2010, 17:39

Just got done running 2 full tanks of fuel thru with the Superchips set on the lowest tow level, over 1000 miles total, all with winter blend fuel. First tank was all city, 35 to 55 mph in traffic driving, took 2 weeks to run the tank out. The DIC said 17 mpg, actual was 16. Filled up and took a thruway trip over the weekend, all thruway averaging 70 mph, all empty driving, 476 miles on this tank, not a full tank run thru, was just over 3/4 gone, DIC said 18, actual was 18.33. So, with this tuner set on the level its at, it is very close the what the DIC predicts, and the power is awesome, can't wait to see how it tows. Checked twice by plugging in the unit to make sure there were no codes present, which there were not. I was hoping for better mileage, but maybe that will improve with summer blend fuel. The power at this setting is exactly what I was hoping for, very smooth and controlled as you ease into the throttle, and very noticeable over stock. They say 44 HP and 79 ft. lbs torque at this setting.
As a side note, I will not be able to compare the Bullydog unit, I attempted to install it and make sure it worked properly, and found out it was not able to load because it was "locked" due to the program being currently on another truck, so I returned the unit. I may just stick with this unit, so far I am very pleased.
If anyone has any experience with the Bullydog powerpup on an LBZ, post your results here for all to see and compare.

mark45678

02-21-2010, 11:07

I havent been around the site from months maybe even a year , I have a 2006 LBZ that I have been running a Kennedy tuned ECM refash. I have been running it every day for 3 ~4 years basicly since the truck was new , I now have 96,000 on it now. It pull really hard in the hills , when I first installed it I noted about 1/2 to 1 MPG better . The truck is a 4x4 crew cab with a cap on the bed with roughtly 800 lbs in the bed plus the cap weight every day. It very rarely gets less then 15 mpg average end in the winter , some long runs without towing it will just touch 19 mpg . I am sure other can claim more but they will be lighter trucks or driving slower , most of the time I run 70~75 mph. The performance /tow tune is about as much hp and TQ you can throw at a stock allison and expect to keep it in good running order for years. I did install a shift improver kit in the valve body and change over to syn oil in the trans , the oil is still clean and almost zero clutch dust in the pan when i had it down at 75K. I will never go back to add on perfromance adder like EDGE or anything like that , i just had my fill of driveablity issue with EDGE products . I have two ecm's one with Kennedy tune and the OEM 2006 tune that has never been touched , I carry both in the truck just in case. JK has a in house chassi dyno and does all of his own tuneing on trucks he owns and drives. strait up my 2006 LBZ is the best running deisel truck I have owned ( 310,000 miles since 2001 on duramax trucks and I have owned 6.5td truck since 1993 )

madmatt

02-22-2010, 05:36

Hey Pete,, are you in IN?? As far as tuners go,, I used to hate on Bully Dog pretty hard but just within the past year I've messed with their products more and perfer some of their stuff over the more traditionally popular tuners available.
Also, I offer EFI Live tuning as well.

madmatt

02-22-2010, 05:45

Teh sound is likely timing. I have not tried that one yet so I cannot comment on safe or not, but will say the LBZ pistons cannot take a lot.

Not that I disagree,, but we have a truck that has been running 11.7s and around 650rwhp-675rwhp for over a year now on the stock bottom end/ stock single cp3 w/o any issues what so ever. although i'm sure i've just jinxed it now hahaha!! It's not the first stock bottom end to survive well into the 11s or over 650 for an extended period of time either. I have heard of and witnessed piston failures at much less hp levels as well though. It seems tuning has a lot to do with it.

pete m

02-22-2010, 19:11

Matt, I am in NY, I bought this truck when I was in Indy in Jan.
I do NOT race this truck, I have a dragster with almost 1000HP plus a NOS kit and a Monza Super Gas car that I race. I only added the SC tuner to get a little better bottom end power for city driving, and maybe help mileage, and also have a little more power when towing. With both cars inside the trailer the total weight is just under 10,000 lbs. I do not intend on towing with this set any higher than the lowest setting, so far its everything I wanted, just don't want to do any damage to the engine.
Do you guys feel the ECM swap is a better thing for the way I am using this truck as far as engine safety and getting a little boost?, or is the Superchips tuner enough, I don't feel i will ever see huge mileage numbers, although with the Edge on my LLYdually I was seeing 15.4 towing this trailer, hand calc'ed, and had the DIC display from 14.5 to 16.

Matt, what is EFI live tuning ?

madmatt

02-23-2010, 18:15

checkout www.efilive.com and/or www.duramaxtuner.com
I don't think a ecm swap is nessacary,, but i feel something like an Edge CS or Bully Dog GT with an egt probe installed is a more user and truck friendly choice being that you can set defuels and safeguards and have gauges to monitor vitals. As far as efi live. I recently tuned a very similar truck and with a tow tune he gained 3 mpg with his 1 ton slip in camper in the bed. results vary though.

pete m

03-08-2010, 19:21

Just wanted to add an update. I finally got to tow my trailer this weekend on a small trip, loaded it was 8000 lbs, is a `28' tag trailer. I had the Superchips set to the lowest setting, the "tow" mode. I cleared the DIC for ecomomy AFTER running 3/4 of a tank of fuel thru it while towing, filled up again, had plenty of power to get up to highway speed and pass a few as necessary. Went 525 miles total, truck had almost no smoke at all, even at 1/2 throttle or a little more, it only spewed a small amount of smoke, and only for a few seconds. DIC showed 13.2, actual was 12.86, not too bad. This setting only adds 44 HP and 80 ft. lbs torque, maybe because its so mild of a tune, it does not alter the DIC that much. My previous LLY truck that had an Edge tuner set on #2 was off over 2 MPG.

Tractorhauler

03-13-2010, 08:30

Pete,
I just sold my 2007 GMC LMM duramax with 28 K and bought a 2006 GMC CC Duramax LLY/LBZ with 214K. I really have appreciated this thread. Thanks for all the good questions. I will use my truck for towing 15 - 18 K trailer weight, so I should be 22 - 25 K Gross.
I have spoken to Kennedy about an ECM upgrade. I picked my truck up in Dallas last week and drove it back north to Nebraska and averaged 21.9 over 965 miles, hand calc'd. I did, however, have a tailwind through TX and OK, but not in KS and NE.
So far I am impressed with the LBZ. I owned a 2002 CC Duramax/Allison GMC and put 135K on it before I traded in. I loved that truck. I had a very early Edge tune and it improved power and economy and I never had smoke. I also upgraded air in and air out. My wife said the 02 ran like a 7000 lb corvette.
I feel like this LBZ/LLY runs like my chipped LB7 with no mods or upgrades. The throttle has not seen the floor yet.
I have considered a 4" exhaust and WAS considering a air intake until this thread.
I am still not sure if I am going to do a Kennedy ECM. I will decide when I see how she does with my Bobcat/tree spade/tree loaded on my 26 foot tiltbed. Last night I delivered a tractor to a farmer 230 miles away. 7K tractor going 65mph and avg 12 mpg loaded going down and 15 on the return with just my trailer.
Again, thanks for the thread. Just my .02
Mark

pete m

03-15-2010, 19:17

Tractorhauler

03-15-2010, 20:50

Pete,
I do have the LLY with the 6 speed. Just the last 2 days driving my short distance to work, no towing, I am getting right at 16 mpg. I sold my LMM 2007 partially to get better mileage because I became tired the the regen horrible mileage and the fact that I could not do any real substantive aftermarket mods without getting flashes of check engine messages.
Mark

Kennedy

03-23-2010, 10:17

Hi Mark, from what I see you have an `06 truck with the LLY motor right?, I, as mentioned got better mileage with my (2) LLY trucks than this LBZ, but can feel the extra power this engine has. I think you have the ability to get even better mileage with yours than I did because my LLY trucks were `05's that had the 5 speed, yours should have the 6 speed which should/could get better mileage due to turning less RPM's, I did notice mine running below 1800 rpm at 69 MPH while towing. I thought with this turning less rpm it would get better highway mileage running empty, but still could not touch either LLY, and the last one was a CC 4X4 dually that weighed a LOT more than my current 2500 HD does. Only thing I have done to my truck is the K&N air filter element, and the Superchips tuner, otherwise its stock.

Wind is more of a factor than RPM in my experience. I'm sure that there are cases where RPM reduction will help, but the Dmax 5 speed is in a pretty good place as far as RPM goes so the extra OD doesn't make a huge difference. The 06-07 LBZ will run pretty darn close to the 05 LLY MPG, but it takes a good tune and restraint on the part of the driver to get it there...