Diesel Tuner's Blog

5.9L 3rd-Gen Cummins Turbo Comparison (Stock, Modified, STR, 64mm, and 67mm Turbos)

[fa icon="calendar'] Feb 8, 2024 2:03:39 PM / by Nick Priegnitz

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This document contains the data we gathered on the chassis dyno while proving out our Stealth series of turbos for the 2003-2007 5.9L Cummins.  This is real, experimental data and therefore may not be perfect.  It represents many hours and dollars of hard work by the team at Calibrated Power and is used by our staff to assist customers in the selection of the best turbocharger for their application.  This data was amassed by instrumenting the truck with a variety of gauges and probes from Banks Engineering and collating data after each steady-state test.   Below you'll find  Nick Priegnitz's personal thoughts on the data.  These are broken down into two parts, the first is an intro to what the data represents and how it was collected followed by a trends in data as seen through my eyes along with some takeaways.   

A quick note on power.  All dyno numbers are reported in 'Mustang RWHP'. Do any googling and you'll see that Mustang Dynos are very stingy.  If you're comparing to 'internet dynojet numbers' add back 12.5% to any dyno number reported here.  Example: if the Stealth 64 (Mach 1) reports 623rwhp on our dyno you can expect 623*1.125=700rwhp on a dynojet. 


Table of Contents: 

1- Turbo Descriptions

2- Steady State Towing test results with PID Info

     a. Lambda

     b. EGT

     c. Shaft Speed

     d. Boost

     e. Drive pressure (ratios)

3- Spool up Test 

4- Max Power Clean (AFR/Lambda limited)

5 -Max Power (Competition use)

6 - Video

7- Conclusion 



1. The turbos (from left to right)

  1. OEM Stock HE351cw- Stock stock stock.  This turbo is a great example of what can be expected from trucks running stock boost limits, either without boost tuning or wastegate mods
  2. OEM Improved HE351cw - This turbo is a stock core with a modified wastegate canister and rod adjustment to spec.  This upgraded wastegate uses a stronger spring to keep the wastegate circuit at higher drive pressures and also allows peak boost to reach about 37psi. 
  3. Calibrated Power STR - This turbo uses an upgraded rotating assembly 60mm x '67 Beastwheel' as well as our upgraded wastegate canister matched to allow about 41psi boost pressure.  
  4. Calibrated Power Stealth 64 This turbo uses an upgraded rotating assembly 64mm x '67 Beastwheel' as well as our upgraded wastegate canister matched to allow about 46psi boost pressure.  
  5. Calibrated Power Stealth 67 This turbo uses an upgraded rotating assembly 67mm x '67 Beastwheel' as well as our upgraded wastegate canister matched to allow about 50psi boost pressure.



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What To-Do If Your Diesel Fuel Gells Up

[fa icon="calendar'] Jan 17, 2024 11:48:10 AM / by Ben Lawson posted in Duramax, LML, 2.8L, L5P

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As the winter months rolls around us diesel owners get an unexpected bit of stress added to our plate. Diesel fuel gelling is a very common issue most diesel owners who live in areas where the temperature drops below 32 degrees will face at least once in their lives. Not only is this issue frustrating and stressful when it occurs, the mere trauma from past experiences can lead to constant stress during these cold times. No one wants to get out of work in the pitch black freezing cold only to find that their truck won't start at all. But what should you do in the event that your truck won't start or stay running? Luckily we have a step by step guide on how to properly fix this issue once it has occurred. 



As a preface, this issue is caused when the paraffin wax used in diesel fuels (for lubricity and proper viscosity) start to solidify.  While gelling can take on varying levels of severity from cloudy fuel all the way to a squishy solid mass. Diesel fuel gelling is never a thing you want to expeirince. At its most mild levels it can cause poorer fuel economy, less power, and be pretty hard on your fuel system. At its worst I can clog fuel lines, filters, pumps and even injectors while potentially causing irreversible damage to your fuel system.  If you live in a cold climate take precautions by adding anti-gelling agent into your fuel before severely cold temperatures start setting in to avoid all of these issues. 

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2017 and 2024 L5P Turbo Comparison W/ Specs

[fa icon="calendar'] Sep 12, 2023 2:13:37 PM / by Ben Lawson

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With the introduction of an all-new L5P Duramax in 2017 the platform also received a completely re-engineered turbo to go along with it. This turbo brought with it a lot of new changes including a completely new compressor wheel, exhaust vane assembly, and electronic vane actuator. With all of these differences, we had to completely re-engineer our machining process for our Stealth line of L5P Turbos. Now that the 2024 Duramax L5P is here with an updated turbo design. We wanted to learn the differences between these two turbos so we could better understand the strengths and weaknesses of each. Along with helping us design a new machining process for the updated turbo.


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What Type of Tuner Is Best For My Diesel Truck? - Box Tuners V.S. Custom Tuning

[fa icon="calendar'] Sep 8, 2023 2:45:00 PM / by Ben Lawson posted in custom tuning, Pre-Tuned

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 When it comes to improving the performance of your Duramax, Cummins, or Powerstroke, diesel tuning is always a great place to start. It offers some of the best value when it comes to price and performance and can make your truck feel like a whole new vehicle. However, when it comes to choosing which type of tuning to go with there seem to be two distinct yet similar options out there, Box Tuners and Custom Tuning. This article will help you decide which option is best for you. 

Box Tuners

How They Work

Box tuners manipulate the data stream of different engine sensors to provoke a desired engine response. In most cases, this consists of manipulating map sensor values in order to trick the ECM into adding more fuel into the combustion chamber. The idea behind this is that most diesel and even gas engines run on the leaner side of air and fuel mixtures. By increasing the amount of fuel in the combustion chamber more air is able to be burned, which in turn creates more power.

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Stock Duramax Turbo Specs and Information

[fa icon="calendar'] Jul 31, 2023 8:00:00 AM / by Ben Lawson posted in LLY, Duramax, LML, LBZ, Turbo, Stock Turbo, LB7, LMM, LB7 Turbo, LBZ Turbo, LMM Turbo, LML Turbo, Duramax Turbo, LLY Turbo, L5P, L5P Turbo

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Over the years, GM has changed a lot regarding the turbos they use on Duramax engines. Not only have they changed manufacturers a handful of times but each RPO has its own unique measurements for key components. This can make it a headache when trying to track down exactly what the measurements of your stock turbo are. Luckily we've compiled this list of stock Duramax turbo specifications along with other helpful information so you can get a good idea of what you're already working with before you dive into the sea of turbo upgrades these trucks have to choose from. However, while some turbos may have the same peak power output, the size and shape of specific components can affect things such as exhaust gas temperature, drive pressure, and turbo efficiency range.  

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GM 3.0L Duramax Custom Tuning

[fa icon="calendar'] May 26, 2023 8:30:00 AM / by Ben Lawson posted in DuramaxTuner.com, duramaxtuner, Duramax, Emisssions Intact Tuning, Emissions Intact, 4 cyl duramax, ECM, Emissions Equipped, 3.0L

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The 3.0L Duramax is a wildly capable inline 6-cylinder diesel engine designed for full-size half-ton pickup trucks and SUVs. Due to its amazing power-to-weight ratio and towing performance, GM has chosen to offer this engine in everything from Chevy Silverado 1500 to the Chevy Suburban and even the Cadillac Escalade. Clearly, GM is confident in its new design. 

The new 3.0L Duramax shares very little in common with its predecessor the 4-cylinder 2.8L Duramax. It's been completely redesigned from the ground up and features many improvements such as a forged crankshaft, forged steel connecting rods, and a much stronger block design. The result is an engine that can produce 277 hp and 460 ft-lbs. of torque. Which is comparable torque to that of the more expensive 6.2L gas engine that is offered in most of the same vehicles that the 3.0L is offered in. 

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10-Speed Allison 1000 T93 Transmission Tuning

[fa icon="calendar'] Mar 21, 2023 6:00:00 AM / by Ben Lawson posted in Transmission Duramax, Transmission Tuning, L5P, L5P Tuning, L5P TCM Tuning

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The ten-speed Allison 1000 is substantially better than previous Allison models we have seen come in Duramax trucks. Known for its superior towing performance, excellent fuel economy, and outstanding reliability. It utilizes some of the best technology GM has ever produced. Its reputation for excellence was earned largely because of the advanced electronic control systems provided by the TCM (Transmission Control Module).

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Differences Between 49 and 50 State Tuning

[fa icon="calendar'] Jan 17, 2023 8:10:00 AM / by Ben Lawson posted in Emisssions Intact Tuning, Diesel Tuning, custom tuning, L5P Tuning, 50-state tuning

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If you've ever been in search of emissions in tact tuning for your diesel truck you've probably come across the 49 state and or 50 state tuning label. While it may only seem like the difference between one state. How much of a difference can one state make? The answer may surprise you. This article will try to answer the top five most common questions regarding 50 state tuning. 

1. What is the difference between 49 and 50 state tuning?
2. Will I only need 50 state tuning if I live in California? 
3. Do 50 state tunes make less power than 49 state tunes?
4. Will 50 state tuning void my factory warranty?
5. Who is 50 state tuning made for? 

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Your 2007.5-2018 Cummins Needs This Turbo!

[fa icon="calendar'] Dec 27, 2022 3:30:00 PM / by Justin Tyson posted in Cummins Turbo

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It's no secret that Calibrated Power's newly designed Cummins 6.7L Stealth 64 Turbo HE351VE / HE300VG Turbos are making their rounds on a ton of 2007.5-2018 trucks. With Calibrated Power's success in developing, designing, and manufacturing the Stealth Turbo for earlier Cummins models, they now take prior knowledge and expertise to give these 6.7L Cummins a top-of-the-line replacement. Once you learn about what went into the design of this turbocharger. We are going to break down exactly why this turbo is the right replacement for your stock 6.7L Cummins.






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High Flow Vanes (HFVs) For Variable Geometry Turbos and Why You Need Them

[fa icon="calendar'] Dec 3, 2022 10:19:00 AM / by Ben Lawson posted in Turbo, Stealth, High EGT's, LML Turbo, Turbo Upgrades, Stealth VVT, Stealth 67G2, L5P, VGT, L5D, Nozzle Ring, High Flow Vanes, Turbo Vanes, HFV

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One of the biggest advancements in turbo design since we first started applying them to diesel engines over 70 years ago has been the invention of Variable Geometry Turbos. These turbos utilize a set of movable vanes on the inside of the exhaust housing that allows the actuator to vary the area in which exhaust gasses can pass through them. This allows the exhaust side of the turbo to increase or restrict the flow of exhaust hitting the turbine wheel. In some designs it also changes the flow direction of gasses hitting the exhaust turbine as you can see illustrated below. 

When restricted, the velocity of the exhaust gasses increases which helps spin the turbine faster than a fixed geometry turbo would. This gives the turbo the ability to spool the turbine and compressor wheel up much better than it normally would even with a low volume of exhaust pressure traveling through the system. This helps to spool the turbo at lower RPMs to create boost where it would normally be lacking. This is why variable geometry turbos (VGTs) are such an advancement. They have the ability to significantly reduce turbo lag and provide much better response and turbo efficiency across a range of RPMs. 

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