LML mods and dyno testing begins
- Thread starter IdahoRob
- Start date
LML MBRP Downpipe install:
Test vehicle: 2013 GMC LML with all factory emissions in place.
To recap our previous testing please check out our Project LML blog http://atptrucks.com/blog/project-lml-duramax/
The downpipe manufacture HP claim is 21hp and 24ft lbs. We will see how this piggy backs on the current mods with HP tune and the S & B intake.
I can tell you the downpipe install is not for the faint of heart. The install is much easier if done in conjunction with a transmission/converter install. Having the transmission out of the way really speeds things up and is much easier on the knuckles and the frustration level.
Even with the transmission out of the way, the install still took about 3 hours. This wasn’t straight time as I dealt with a few interruptions along the way, but a good baseline none-the-less. If the transmission is in the truck, I’m estimating 4-6 hour install and some bloody knuckles. Everything bolted up fine without having to modify anything on the truck and no special tools needed.
I don't have back to back, same day numbers but I used same load and same SAE correction factor.
Dyno'd 500.66 RWHP with the DPF system showing 40 soot grams (basically ready for a regen). This shows a gain of approx. 25hp. I was a bit skeptical because the SAE correction factor showed a different percentage as the runs were during different days so I ran the uncorrected numbers and the downpipe showed a 16hp gain. The dyno graphs show the info on the different conditions of the runs. Personally I’m leaning towards a 20HP gain.
So truck mods to date to hit this 500hp number; MikeL trans, ATP tuning, S & B dry intake, MBRP downpipe. The next test will be an AirDog 4G lift pump. With the rail pressure dropping under load, I feel this will be a nice addition to HP and longevity of the fuel system. Stay tuned.
Test vehicle: 2013 GMC LML with all factory emissions in place.
To recap our previous testing please check out our Project LML blog http://atptrucks.com/blog/project-lml-duramax/
The downpipe manufacture HP claim is 21hp and 24ft lbs. We will see how this piggy backs on the current mods with HP tune and the S & B intake.
I can tell you the downpipe install is not for the faint of heart. The install is much easier if done in conjunction with a transmission/converter install. Having the transmission out of the way really speeds things up and is much easier on the knuckles and the frustration level.
Even with the transmission out of the way, the install still took about 3 hours. This wasn’t straight time as I dealt with a few interruptions along the way, but a good baseline none-the-less. If the transmission is in the truck, I’m estimating 4-6 hour install and some bloody knuckles. Everything bolted up fine without having to modify anything on the truck and no special tools needed.
I don't have back to back, same day numbers but I used same load and same SAE correction factor.
Dyno'd 500.66 RWHP with the DPF system showing 40 soot grams (basically ready for a regen). This shows a gain of approx. 25hp. I was a bit skeptical because the SAE correction factor showed a different percentage as the runs were during different days so I ran the uncorrected numbers and the downpipe showed a 16hp gain. The dyno graphs show the info on the different conditions of the runs. Personally I’m leaning towards a 20HP gain.
So truck mods to date to hit this 500hp number; MikeL trans, ATP tuning, S & B dry intake, MBRP downpipe. The next test will be an AirDog 4G lift pump. With the rail pressure dropping under load, I feel this will be a nice addition to HP and longevity of the fuel system. Stay tuned.
I agree, the LML down pipe does suck! Really, the worst part of the job for me is removing the heat shield. I didn't realize you were doing all this without a lift pump. Would you be willing to share how much pulse width you're running on that tune, and how far is pressure dropping?
I have roughly 3k miles on my LML modded charger. After the first set of tunes came over we topped out at 611/1127 on the dyno. That was in the street tune, slightly over fueled. The max tune was down to 586 heavily over fueled. Once i data logged Kory cleaned up alot of the smoke but still is slightly lazy on the very bottom. Were switching turbines and changing a couple other things to see the difference.
Egt's were never over 1500* and boost maxed out around 48psi.
Truck is a 15', PPEI, cp3, full exhaust/dp, Dmitri trans, and Fass 150.
I'm def not a turbo guy, just wanted to share with the more knowledgable ones on here.
Egt's were never over 1500* and boost maxed out around 48psi.
Truck is a 15', PPEI, cp3, full exhaust/dp, Dmitri trans, and Fass 150.
I'm def not a turbo guy, just wanted to share with the more knowledgable ones on here.
I think it took Troy and I 4 hours to do a downpipe, full delete and intake on my 2011 LML. That was the first time I ever messed with one also.
Are the new body styles harder? I guess I'll find out on my '15 when the time comes...
Are the new body styles harder? I guess I'll find out on my '15 when the time comes...
Still running all factory emissions.
We added an Airdog 4G lift pump to the truck. Driving impressions; The truck seems to have better throttle response in a mild tune just with mild TPS input. May of been just my mind justifying the pump, but since it is my daily driver, I have a good feel for the truck.
This pump is almost silent. I cannot hear it with the key on and engine off sitting in the cab. Standing next to the truck with engine off, you have to bend down and put your head next to the pump to hear it is running.
On to the dyno numbers. Same tune as all the other testing was used. Soot grams up to 39 grams about where the last test pull of 500HP was. The truck made 532RWHP. The curve is much better with added HP coming in the full length of the pull. The SAE correction was higher today but so was the temp(94* compared to 77*) and the Humidity was also higher (39% compared to 13%) so I feel fairly accurate gain between tests.
We added an Airdog 4G lift pump to the truck. Driving impressions; The truck seems to have better throttle response in a mild tune just with mild TPS input. May of been just my mind justifying the pump, but since it is my daily driver, I have a good feel for the truck.
This pump is almost silent. I cannot hear it with the key on and engine off sitting in the cab. Standing next to the truck with engine off, you have to bend down and put your head next to the pump to hear it is running.
On to the dyno numbers. Same tune as all the other testing was used. Soot grams up to 39 grams about where the last test pull of 500HP was. The truck made 532RWHP. The curve is much better with added HP coming in the full length of the pull. The SAE correction was higher today but so was the temp(94* compared to 77*) and the Humidity was also higher (39% compared to 13%) so I feel fairly accurate gain between tests.
I tested at the track before the lift pump install. The same tune that made 500HP without a lift pump didn't perform on the 1/4 mile. Dropped rail bad about 3rd gear and didn't recover for a while running 14.2's with 2.0 60' times.
I installed a tow tune with mild pulse and the truck went 13.8 with the same 60' times.
So 500hp on the dyno before lift pump really wasn't a 500hp tune on the street under full load conditions. I feel the lift pump will be a much better addition for performance driving conditions compared to short dyno pulls of a few seconds. So IMHO the lift pump is the best bang for the buck that we have tested to date (besides tuning that is)
I installed a tow tune with mild pulse and the truck went 13.8 with the same 60' times.
So 500hp on the dyno before lift pump really wasn't a 500hp tune on the street under full load conditions. I feel the lift pump will be a much better addition for performance driving conditions compared to short dyno pulls of a few seconds. So IMHO the lift pump is the best bang for the buck that we have tested to date (besides tuning that is)
Good to hear the new AirDogs are quieter, you can hear mine over the motor easily. I'm really impressed with the output you get on a basically tune-only LML, and with full emissions gear at that!
This is making me look at the new trucks in a different light. Thanks for posting all this info!
This is making me look at the new trucks in a different light. Thanks for posting all this info!
Also shows the difference between real world track testing and a dyno pull:cool2:
The results make me want to buy a lift pump and downpipe and finally get this truck tuned. Problem is I don't have 4k for a trans right now...lol On a serious note, what about regen frequency? I would think it would be up quite a bit.
The regens with this tune are not too much different than stock. I'm around 350 miles in city driving and bumping up to the 700 mile limit on all highway driving. DEF usage seems lower, I'm not sure why. Winter fuel increases regens for sure. I averaged 18.2 mpg on a trip to Oregon for racing and that included 10 passes on the 1/4 mile and about 20% city driving (before the lift pump install).
I will say when I bought this truck stock, I wouldn't even drive it as the dead peddle was so bad.
Now, I can honestly say this is the most fun duramax I have owned for street driving and I've owned some good ones. The truck spools amazingly and has a very quick feel for how heavy it is.
I do not recommend buying a LML and think you are going to build a 10 or 11 second truck as the efi live tuning is no where close to tuning a highly modded LML. Still way to many hidden limiters and tables that do nothing. But for a really fun daily driver, the LML is a blast. with tuning and a few bolt ons.
I will say when I bought this truck stock, I wouldn't even drive it as the dead peddle was so bad.
Now, I can honestly say this is the most fun duramax I have owned for street driving and I've owned some good ones. The truck spools amazingly and has a very quick feel for how heavy it is.
I do not recommend buying a LML and think you are going to build a 10 or 11 second truck as the efi live tuning is no where close to tuning a highly modded LML. Still way to many hidden limiters and tables that do nothing. But for a really fun daily driver, the LML is a blast. with tuning and a few bolt ons.
I wouldn't hesitate to buy a LML and keep full emissions and let Rob tune it! California emission of course....
Thank for all the input and testing Rob
Thank for all the input and testing Rob
I am at 350-400. I think it does not matter if I am towing, cruising highway or city. I think my truck is on a schedule set by the stock tune.
Here's an update on this long term project with some data. I have been using the same 530hp tune that was loaded back last summer.
I’ve kept detailed data on regens since last summer. The regens during the fall and winter have been less frequent for some reason. All City driving and the truck will regen on average once in a tank (450-500 miles).
I was shocked on the results of some long mileage testing this winter. Mostly highway driving on the first test. I made a 750 mile trip, 70 mph average into a heavy head wind, some 4x4 and snow and a load in the bed, the truck gained 10 soot grams during this trip. It didn’t regen in that trip, which surprised me as I had heard that the LML will regen every 700 miles even if the DPF is not full.
I then made another trip covering 900 miles, averaging 83 miles per hour when on the highway(we have 80mph speed limit). I had about 200 city miles on it since last regen and was sitting at 15 soot grams before hitting the highway. I went 400 miles and gained only 1 soot gram. Next day drove 200 miles with some wide open blasts and gained 7 soot grams (went and visited some tuning clients and took it out for some HP testing). So the truck was sitting at 22 soot grams and had approx. 800 miles on it without a regen. The next day I was back on the highway for a 400 mile trip home. 80+ mph and the truck actually lost 3 soot grams down to 19 soot grams, in the next 200 miles. Conditions must have been just right and it was passively burning any particulate that the engine was making.
I finally found the limit my truck will go before it manually regens, 1000 miles on the button. The truck was at 19 soot grams total gained at the 1000 mile mark and it went into regen. Normal regen takes place at 44 soot grams. The truck had no reason to regen except a fail-safe setting in the ecm. Pissed me off as I wanted to see how far it could go without regen. At least I now have hard, concrete evidence that there is a forced regen at 1000 miles and not the 700 mile range previously thought.
Pretty cool numbers on a 500+HP tune. I’m not sure why the regens are less frequent, I have a hard time believing it is the aftermarket hard parts added but the numbers are what they are.
My next test is installing an emission compliant twin turbo kit from ATS. They have been working very hard on a compliant kit that keeps the heat in the exhaust side of the system. This heat is needed in passive and active regen. I’m really looking forward to gaining data on how this turbo set-up will work on the regen side, as well as, the HP side of things. The goal is to have it installed this month and I’ll make sure to do a write up.