2017 – 2023 GM 6.6L L5P Duramax | Transmission Tuning by T&B

What does PPEI’s tuning do for my L5P Duramax

• Tuning is intended to increase the horsepower (hp) and torque (tq) the engine can produce. OEM manufacturers, like GM, show vehicle hp and tq based on the amount of power produced by the engine, at the engine, which is 445 hp and 910 lb-ft of torque.

• PPEI, unlike the OEM, measures hp and tq at the wheel. What does that mean? – It means PPEI measures power that the vehicle produces to the ground showing the amount of powertrain loss from the engine, through the transmission, to the wheels. PPEI refers to this as the “baseline,” in this case, for the L5P Duramax, we measured 437-wheel hp and 844-wheel tq. The baseline shows a powertrain loss of 8 hp and 66 lb-ft of tq.

• PPEI’s primary focus when tuning or creating a calibration is focusing on the overall efficiency. Many individuals search for the most horsepower & torque and view it as the “best tuning,” however, more times than not, it’s quite the opposite. Many tuners advertise tuning based on the highest hp & tq, surpassing the threshold of efficiency. When the threshold of efficiency is overpowered, issues start showing up, which can be as minor as poor fuel economy or as significant as transmission and engine failure.

• At PPEI, we love our performance, but we develop all calibrations around reliability, giving you peace of mind no matter the situation. Whether you’re at the dragstrip or hauling a heavy trailer across the nation, PPEI’s L5P calibrations redefine the limits and safely go beyond the OEM’s performance.

• PPEI’s L5P calibrations produce up to an additional 157-wheel horsepower and up to an extra 363 lb-ft of torque above the OEM baseline. PPEI’s L5P performance calibration brings the overall horsepower up to just shy of 600-wheel hp and 1200 lb-ft of torque. Furthermore, PPEI offers a seamless method to change between 6 different power levels (tunes) through the factory steering wheel. Each tune serves a specific purpose. However, some people may say, “just leave it in the highest hp and drive easy.” PPEI does not recommend that method. Here is why PPEI suggests using the proper power level for each specific driving condition.

PPEI L5P Power Levels Defined

Why PPEI recommends tuning

• PPEI doesn’t recommend all tuning. We only recommend proper tuning. So, you may wonder, what is proper tuning? Proper tuning means the calibration is designed specifically for the parts your vehicle may have installed. You wouldn’t want a calibration designed for racing if you need a calibration specifically for towing. You wouldn’t want a calibration from an individual or company that doesn’t have the ability to support the service you purchase. You will want tuning from a reputable calibrator who can back up and show data supporting what you purchase. PPEI recommends doing your homework, but ultimately, we recommend PPEI tuning above all else because PPEI has the team and the data to back the services you purchase.
• From hotshot drivers to daily commuters, PPEI has everything you may need to improve the overall efficiency of how your vehicle operates in any situation. Some individuals will make claims of increased fuel economy. However, at PPEI, we claim improved fuel consumption may be achievable under specific driving conditions and driving styles.
• We understand at PPEI that you ended up here, reading this because you want your L5P Duramax to do something better or different than it does from the factory, and that’s precisely what we are here for. PPEI’s goal is to provide you with a service that exceeds expectations, just as our calibrations redefine how your vehicle operates in all aspects.

How does your vehicle benefit from tuning

• You can make your L5P accelerate quicker, go faster, tow better, or simply be more enjoyable to drive. You are probably thinking, “that doesn’t really tell me how my vehicle benefits from tuning.” Well, your question is correct. There is no actual impact on your truck when using your L5P correctly, meaning when you are towing more than 15,000 lbs. use the heavy tow tune. When you are daily driving, use the all-purpose calibration. Think of your vehicle as a tool. It has an intended purpose which it helps you get somewhere or do something. In reference to tools, you aren’t going to use a hammer to change a light bulb or put air in your tire, just like you wouldn’t tow in the performance calibration. Using the wrong tool for the task at hand will create more issues than it solves. It all comes down to servicing your truck correctly. With the right tools and the right parts, your l5P Duramax will last a very long time and retain reliability. There are other preventive maintenance products that you can use and purchase from PPEI to help prolong the life of your L5P. For more info, contact PPEI here to learn more.

What can PPEI calibrate for my L5P Duramax

• The L5P Duramax has many modules that control how the truck functions. However, PPEI only focuses on the powertrain and how it operates. The powertrain consists of the engine and transmission. The engine is controlled by the Engine Control Module (ECM) or can be referred to as the ECU meaning Engine Control Unit. This particular ECM/ECU is an E41 controller specific to the L5P Duramax. It controls all of the electrical engine components such as fuel injection, turbo functions, and other electrical accessories associated with how the engine operates. The transmission is controlled by the Transmissions Control Module (TCM) or the TCU, meaning Transmissions Control Unit. The TCM is known as the T87A, specific to the L5P Duramax controlling everything from shift point, converter lock-up, line pressure, and many other electrical parts connected to the transmission. The ECM and TCM communicate with each other at all times and even develop an adaptive memory of your specific driving style over time.

Are PPEI tunes going to affect the reliability of my L5P Duramax

• Ideally, you would think, “If I increase the power, I will also decrease reliability.” In some cases, that is very true, primarily when the threshold of efficiency has been surpassed. Knowing how your calibrations work and what the calibration is designed for is very crucial. As long as you follow the guidelines PPEI provides, the PPEI calibrations will not reduce the reliability of your L5P Duramax. If you use the incorrect power level for the wrong task at hand, there is a much higher chance of decreasing the reliability. Reliability comes down to maintaining your truck and keeping it serviced with the correct oil, air filter, oil filter, transmission fluid, coolant, and all associated parts that are incorporated within your L5P’s powertrain.

Stock L5P Duramax Vs. PPEI Tuned L5P Duramax results

• When explaining how tuning works, it can be challenging to express the actual difference in words without visual representation. It also helps if you can understand what you are looking at. PPEI uses a series of different tools to measure the power of each vehicle to show a gain or loss in performance. At PPEI, we use chassis and hub dynamometer, aka dyno’s, to measure overall force, such as horsepower and torque. We also use performance GPS devices to record ambient air temps, humidity, elevation, distance, acceleration, and speed, along with data logging equipment to record the actual output vs. the desired inputs. Basically, as a calibrator, you demand the vehicle to hit set points within the calibration. In some cases, the actual value may differ due to a limiter within the ECM or TCM. When these limiters are found, it helps the calibrators at PPEI improve how each vehicle operates in the tuning development process. Here are the performance test results for the L5P Duramax comparing the PPEI calibration to the OEM stock baseline calibration.

OEM Stock L5P vs. PPEI Tuned L5P 0 – 60 mph

0 – 60 mph – this test consists of a few different measurements.

Distance – total feet traveled to achieve 60 mph

Elapsed Time – how long it takes to go from 0 – 60 mph

Acceleration (g-force) – the change in velocity from 0 – 60 mph

Slope – the % of change in elevation between 0 – 60 mph

Distance – the distance traveled to achieve 60 mph is very noticeable when comparing the OEM stock L5P to the PPEI tuned L5P. While it took the OEM Stock truck 346 ft to achieve 60 mph, the same L5P with only the PPEI ECM & TCM calibration reached 60 mph 70 ft sooner for a total distance of 276 ft.

Elapsed Time – the length of time taken to travel from 0 – 60 mph is notable when reviewing the data compared between the OEM stock L5P Duramax and the PPEI tuned L5P. Like the distance test, the elapsed time test showed a very similar result. The OEM stock calibration traveled from 0 – 60 mph in 6.92 seconds, while the PPEI calibration enabled the same L5P to reach 60 mph 1.08 seconds quicker for an impressive time of 5.84 seconds.

Acceleration – this model displays the amount of g-force exerted by both the OEM stock and PPEI tuned L5P. As both the OEM Stock calibration (in gray) and the PPEI calibration (in blue) speed from 0 – 60 mph gaining momentum, the PPEI tune continues to pull where the OEM stock calibration starts falling off around 30 mph. This indicates that the PPEI calibration maintains a more constant torque curve meaning a longer powerband throughout the acceleration test.

Slope – will always remain constant throughout all PPEI performance tests. As long as the percentage of elevation change is between -1% and 1%, PPEI will honor the results from each test. For this test, there was as much as a -0.38% slope to as little as 0.12% slope. There was less than a 1 ft change in elevation over the total distance traveled when performing this test.

OEM Stock L5P vs. PPEI Tuned L5P 30 – 80 mph

30 – 80 mph – this test consists of a few different measurements.

Distance – total feet traveled between 30 – 80 mph

Elapsed Time – how long it takes to go from 30 – 80 mph

Acceleration (g-force) – the change in velocity from 30 – 80 mph

Slope – the % of change in elevation between 30 – 80 mph

Distance – the amount of ground (ft) covered when accelerating from 30 – 80 mph is worth noting because that’s an exact simulation as if you were merging with traffic, on an interstate, from the on-ramp. While the distance may seem irrelevant, not all on-ramps are the same length, which can also apply to other situations such as passing or overtaking the vehicle(s) in front of you. The OEM stock L5P calibration takes 716.3 ft to accelerate from 30 – 80 mph, while the PPEI calibration shows major improvement by accomplishing the same task 168.91 ft sooner. The PPEI calibration enables the L5P Duramax to travel from 30 – 80 mph within total distance of 547.39 ft.  which is 26.7% shorter in overall distance, which makes merging, passing, and overtaking other vehicles effortless.

Elapsed Time – like the distance test, the duration of time between 30 – 80 mph just highlights the untapped penitential these L5P Duramax’s come with from the factory. The OEM L5P calibration can accelerate from 30 – 80 mph in 8.3 seconds where the PPEI tuned L5P does the same performance test 1.92 seconds faster. Speeding from 30 – 80 mph in 6.38 seconds, the PPEI calibration shows a substantial performance improvement over the Stock calibration.

Acceleration – where the OEM Stock L5P and the PPEI tuned L5P have different distances and elapsed times, the start and finish speeds remain constant. By looking at this model it measures g-force between the OEM stock and PPEI tuned calibration showing a constant improvement throughout the powerband when accelerating from 30 – 80 mph.

Slope – will always remain constant throughout all PPEI performance tests. As long as the percentage of elevation change is between -1% and 1%, PPEI will honor the results from each test. For this test, there was as much as a 0.18% slope to as little as -0.05% slope. There was less than a 1 ft change in elevation over the total distance traveled when performing this test.

OEM Stock L5P vs. PPEI Tuned L5P ¼ mile

¼ mile – this test consists of a few different measurements.

Distance – which remains constant at 1320 ft or ¼ mile.

Elapsed Time – how long it takes to reach a ¼ mile

Speed – the top speed reached over the course of a ¼ mile

Slope – the % of change in elevation over the distance of ¼ mile

¼ mile – Since the distance is predetermined, it is easier to analyze the test as a whole instead of breaking down each aspect of this performance test into individual parts. On the left, the OEM stock L5P model (in gray) shows an elapsed time of 15.06 seconds at 92 mph in the ¼ mile as our baseline performance result. The PPEI calibrated L5P model (in orange) shows a progressive improvement as the distance increases producing an additional gain of 10 mph over the OEM for a top speed of 102 mph. Where the speed increases, the elapsed time decreases by 1.02 seconds for a quicker and faster total time of 14.04 seconds. Where this performance test may be irrelevant for your specific needs, it highlights what your L5P is capable of.