Need Performance Advice

[hogbody]

I have a 2003 LB7 and pull 11,000 lb. trailer with a heavy tounge weight. The truck has 45,000 miles on it. I replaced the stock tires with 265's for an extra weight margin. Since doing so I have noticed a slight performance drop. Of course the speedo is off and the DIC is now out of whack.

I am not big on major performance upgrades and I am retired so $$$ are limited.

I've started considering a tuner and have looked at the Preditor, Edge Attitude, and the new Banks Bullit. I would only use it when towing which is 90% of vehicle use. I am looking to replace what I "feel" was lost in performance when putting on new tires and the best ecomomy possible. I also would like to restore speedo and DIC accuracy if possible. (i do have gps to check speed). It would need to be easily removable/untraceable for warranty reasons and I would like an included EGT guage.

I don't want a warranty hassle. I don't fully understand how these things work and the + and - of each product.

This truck is the best rig I have in 35 years and I don't want to cause problems and unreasonable expense.

Thanks, Larry

[Kennedy]

Mark Rinker does a lot of towing and has reported performance AND mpg gains with his KD Custom tuning.

[taznj63]

Look into the predator progammer. It will do a power boost program and you can fix the speedo problem.
I have my "New to me" 2001 dmax, I just drove 1700+ miles from denver to NJ. I kept the truck stock for the first tank of fuel. MPG was 15.4 and average speed was 75mph on flat land.
I bought the programer and brought it with me and after the first fill up I used it to reprogram for the 40hp gain.
OMG... I could not believe the difference!
More power, faster acceleration, more feel in the seat with lighter foot pressure. And my MPG went up to 17.6 still driving 75-80mph flat thru kansas.
My truck has 155000 miles on it and the injectors were replaced at 145000.
I found this programer on e-bay for around 300 bucks.
Oh, and this will monitor the engine, look at and reset engine codes.

Jeff...

[DickWells]

The Hypertech tuner dosn't have the greatest reputation here in the DP, but, that's what came with my truck, so, that's what I've used now for a year, with good results. I've kept it on level 3 most of the time. The power increase is near unbelievable. My towing mileage has averaged just over 12mpg. That's towing an 11,000 lb trailer, plus about 1,600 load in the truck. I get from 17 to 19.6, solo.
I've rolled my tires on a good smooth surface, measured the circumference and progamed it into the computer. My odom. checks out dead accurate on measured miles.
The H -Tech can be put back to stock tuning in about 4 minutes.
The H-tech is one of the cheapest on the market, I think.
Now, I just ordered an Edge Juice W/Attitude, which I'm going to piggy-back to the Hypertech. Easy to do, I understand. I'll leave the H T on either stock or level one. My son has an 03 DM - 3500 Dually with Edge Juice-W/ AT. Loves it for the new power and the monitor read-outs.
If I felt that I only needed an EGT readout, I'd be very contented with a Hypertech programer, and a gauge on the post, or dash. You'd love the extra power. Pretty hard to beat the ego boost this old hillbilly gets when some young blighter comes off an on-ramp with a BMW at 40 mph and can't get by you, (can't even catch up to you), until you let off at 80-90! That's solo, not with that 11 K trailer, off course.
Good luck with whatever you get.
DW:)

[hogbody]

I am leaning towards the Predator or Edge with Attitude. The positives of the Predator are the tire size recalibration and east of installing and uninstalling (in case warranty work is needed) The negatives are it does not monitor engine EGT and boost and doesn't adjust the DIC. The price is affordable. It is strong on trouble codes and such.

The Edge doesn't apparently allow for speedo adjustment but has a neat display that monitors EGT and such. It is more expensive. Its negative is that it looks like it is more difficult to remove and put out of sight when the rig goes in for service. It is the medium price option because guages won't be needed.

A custom tune looks like a great way to go especially with a seperate ECM but $900. + guages is out of my league.

I guess I'll need to break down a put guages on....

I guess they call it the begats.....do one thing it always causes something else to happen.

I'll look into the hypertech.

Thanks for the suggestions and looking forward to more.

[Mark Rinker]

Kennedy's tune is very smooth in comparison the the Predator. I have run both and found his tow tune to improve mileage and make the DMax quieter than stock when towing. Not cheap - but worth the extra $$$ in my opinion.

While gauges are a good idea - I think you could get a custom tune to take care of your towing needs, tire size change, and use it safely without gauges. I am not running any on the 2002.

One interesting observation: The oil in the 2002 (with 190k miles on the odometer) only turns medium brown and remains transluscent - not black and opaque between 10K mile oil changes now. The difference dipstick to dipstick between the 2001 and the 2002 is dramatic. I attribute it to complete combustion and no soot with JK's tune.

[SoTxPollock]

Quote from: One interesting observation: The oil in the 2002 (with 190k miles on the odometer) only turns medium brown and remains transluscent - not black and opaque between 10K mile oil changes now. The difference dipstick to dipstick between the 2001 and the 2002 is dramatic. I attribute it to complete combustion and no soot with JK's tune

Mark, that is a major accomplishment and really important to folks who want to pollute less. If there is less soot in the oil there has to be less wear. That's BIG. No, in fact, I guess my regard for John Kennedy just went up another level.
For guys that haul cross country like you do the cost is nothing compared to what it will save you if that is really what is happening. Makes sense to me.

[50+]

Question for Mark Rinker, and Dick Wells. What upgrades have you guys done to your intake and exhaust? I'm starting to upgrade my LLY, and am thinking about exhaust. Thanks.

[DickWells]

:) Mark will probably step in here with the right poop, but here's my humble input, FWIW.
My truck is an LB7, made in Nov. 03. So, up-grades to an LLY may result in a higher output, overall, since the LLY seems to have quite a bit more grunt, out of the box.
I just installed an S&B air system, 3 days ago. Can't tell yet, what kind of gains, if any, from that. I did it because I needed a new air filter anyway, and wanted to free up the intake for any other add-ons, down the road.
I went back to stock with the Hypertech, before I installed an Edge Juice W/Attitude, 2 days ago. Kept the Hypertech to retain the accurate tire size/speedometer settings. Wanted the Attitude monitor to get EGT and boost redouts without spending the extra for gauges, in addition to 5 levels of power, on-the-fly. So far, I love it. A really noticeable difference, especially on launch, on level 2 compared with the HT on level 2! Much more solid feeling, at my usual throttle opening, felt under my right foot.
Next step will be 4" exhaust, side exit, front of the tire. I put in air suspension over Christmas, at home, and can't use the rear exit. I turned a piece of the old tail pipe down in front of the axle, and that's where it is, still, with the stock muffler. Gotta change that. Don't like the sound, and the RR shock is getting black.:( If I could afford it, I think I'd go with a Corsa, but I can't and I won't. Need to research this. Have to order one that uses the stock hangers, but will exit the side.
Hope this is of some interest. Any questions, just ask.
DW:)

[50+]

I sort of fell into a deal I didnt want to pass up on a Bully Dog Power pup. A friend of mine sells them and had one for an LLY that was ordered by mistake for a LB7. So he said take and play with it, if you dont want it just bring it back. Well, I've only ran it on level 1, but now its mine. He sold it to me for 1/2 price. I'm not going to tow with it without either being able to read egt's or changing my ehaust. The LLY handles my 10,000 lb trailer easily anyway.

[DickWells]

Sounds like you got a good deal. Warantee issues, if they occur, could probably be delt with through the guy that sold the BD to you. The dealer that sold me the Edge, said that both BD and Edge are getting pretty sticky about dealing directly with customers/users, since they've both changed hands recently. I went with a new unit because of that. Got the Edge Juice W/Attitude for $640, including shipping. Not a super deal, but I can get help from the dealer if a problem occurs.
Looks like you're headed in the right direction with your unit. Keep us posted.
DW:)

[50+]

Sounds like you got a good deal to me. I'm gonna play with the BD and see what kind of mileage I can get, back and forth to work. I hit a fair share of stoplights and hand calculated get about 16.8 to 17.4, depending on my right foot. I'll keep you posted.

[Stlheadake]

I JUST ordered the Kennedy Custom Tune and 4" Turbo back exhaust. I HAVE NOT installed the tune yet. However I changed the exhaust about 1200 miles ago. All I can say is WOW!

The truck sounds better, but right off the bat I noticed the change in mileage.
I have honestly seen my MPG go from around 14 mpg around town to 15. I also know that when I hammer and go to WOT (for passing only;) I HAVE PRACTICALLY NO SMOKE!!

I am back from my business trip and that custom tune will be in VERY soon! I can't wait! One last thing, Kennedy's exhaust uses the factory hangers. I'd bet that you could work something out with him for customizing that exhaust.

He's very easy to talk to and he knows his stuff!

Scott

[50+]

If I go any further, exhaust is definately the next step. From what I read here you should be very happy with your Kennedy tune. Keep us posted.

[killerbee]

Quote from: One interesting observation: The oil in the 2002 (with 190k miles on the odometer) only turns medium brown and remains transluscent - not black and opaque between 10K mile oil changes now. The difference dipstick to dipstick between the 2001 and the 2002 is dramatic. I attribute it to complete combustion and no soot with JK's tune

Mark, that is a major accomplishment and really important to folks who want to pollute less. If there is less soot in the oil there has to be less wear. That's BIG.

For guys that haul cross country like you do the cost is nothing compared to what it will save you if that is really what is happening. Makes sense to me.

The truck doesn't pollute less. It pollutes more. In point of fact, donning a tune that defeats the EGR (that is what is required to observe less black in the oil) is highly illegal, with fines that begin at $10,000 (IIRC) for the business owner who does it. I think that is per incident. Google "clean air act" and "fines" if wanting to research it. The fines do apply to individuals also, and ignorance does not qualify as a defense.

In any event, an egr blocker, for $5, or simply unplugging it, is a far cheaper method.

"Smokeless" tunes, using air correlated fuel limiting, is a good idea. EFILive offers this capability. Equipped with a custom PID, the "mixture" is easy to monitor, and anyone can make a smokeless tune that has the beef and driveability of a tame performance tune. Extra locked ECM is not required. I don't believe this will keep oil cleaner however, like the egr defeat. Soot recirculated into the cylinder, via egr, is the sure way to keep oil cleaner.

[Mark Rinker]

(Sorry, I missed the updates on this thread for a couple of weeks.)

My 2002 LB7 with JK's tuning is running stock intake and exhaust.

My only comment on upgrading LLY trucks that will be towing, would be to watch your intake air charge temps carefully. As most of you know, there were plenty of LLYs with overheating issues in stock trim, some under only moderate towing loads. My '05 LLY was left bone stock for the 80K I used it, and only exhibited mild overheating in summer months, compared to the LB7s hauling the same loads.

Here is an article written by a DP member, and LLY owner. What I take away from this is you better trust who writes your LLY code if you upgrade it. Depending on their knowledge of the LLYs factory limitations, they could solve the issue, or make the issue much, much worse.

http://members.cox.net/beekiller/GMC%20Light%20Duty/THERMAL%20FEEDBACK%20LOOPS%20IN%20TURBOCHARGER%20A PPLICATIONS.doc

Personally, my vote would be with JK's LLY tune, as he does extensive realworld testing on and off the dyno. Personally, I wouldn't mod any LLY and tow with it, without gauges - and specifically an intake air charge temp gauge, after reading this article.

[killerbee]

Not coincidentally, the 3rd Gen vehicles now have intake temp monitoring. I think it is referred to as an "AAT" input, ambient air temp, which IMO is a complete misnomer as it is monitored post-CAC. Important ignition parameters are now adjusted based on air condition immediately pre-intake. That may have been a pre-required change for GM to adopt the bosch PCM package.

[More Power]

KB, excellent work on the linked piece!

Real-world test data can be of some use to support the theoretical. For example, we know raising boost pressure increases IAT, but does the boost increase help or hurt power or ECT when towing a 10K trailer up a long steep grade. That's really the bottom line. Bring your truck to MT this July, and we'll test all you want. :)

Jim

[Kennedy]

Not coincidentally, the 3rd Gen vehicles now have intake temp monitoring. I think it is referred to as an "AAT" input, ambient air temp, which IMO is a complete misnomer as it is monitored post-CAC. Important ignition parameters are now adjusted based on air condition immediately pre-intake. That may have been a pre-required change for GM to adopt the bosch PCM package.


Killerbee still has no clue. AAT is just that Ambient air temp or the air temp as it enters the air box. It can be dangerous to believe someone with so little knowledge of what is going on with the Duramax engine.

Here's where Killerbee was so naive to think that he was getting 30.5 mpg:

http://www.thedieselgarage.com/forums/showthread.php?t=23769

For JohnQ dieselowner to be fooled by the DIC, is understandable, but a guy writing papers and proclaiming to know what he's talking about should certainly have enough common sense to verify his test results. How do you trust any data from an "engineer" who cannot even make simple MPG calculations?

Then there's the whole "degas" thing where a condition was described in which the reservior cap wouldn't vent inward and gradually the coolant level dropped (in abscence of any leaks) by some mystery of twisted science.

This was followed by the use of the old 2001 and "gasser" airbox that GM did away with after their first year of production due to problems...

[killerbee]

KB, excellent work on the linked piece!

Real-world test data can be of some use to support the theoretical. For example, we know raising boost pressure increases IAT, but does the boost increase help or hurt power or ECT when towing a 10K trailer up a long steep grade. That's really the bottom line. Bring your truck to MT this July, and we'll test all you want. :)

Jim


Jim, would love to. But I'm going to use the good sense God gave me and move on.

It was nice chatting. Good luck with the trucks Mark.

[SoTxPollock]

Message for killerbee:
Marks 2002 with the cleaner oil never had an egr valve to defeat. Now go back and read your post of how he's polluting more. Perhaps you will draw the correct conclusion.