Drop Forged Diesel · Houston, TX
DIESEL
PERFORMANCE
BLOG
Build guides, platform tech, and shop notes from the bench — written by the people doing the work, not a content agency.
Featured Article
Platform Tech
Why the CP4 Fails and What To Do Before It Does
The CP4 injection pump failure isn't random — it's a predictable result of aeration,
low inlet pressure, and fuel quality variation. We break down the failure chain,
which trucks are affected, what a failure costs, and why a lift pump and CP3
conversion are the correct response before you ever see a symptom.
Understanding this is the difference between a planned modification
and a $15,000 lesson.
Read the Article
Build Guides
Cummins · Power Stroke · Duramax
Build Guides · Cummins
EFI Live Multi-Profile Tuning on Cummins: Street, Tow, and Pull from One Switch
How the DSP5 switch works, why multi-profile matters for trucks with more than one job, and what goes into each calibration profile we build for a sled pull truck that still drives to work.
Build Guides · Fuel System
FASS vs. AirDog: How We Choose a Lift Pump for a Diesel Build
Both FASS and AirDog are capable lift pump systems. We explain how we size a lift pump to the build, why frame-mount matters, and how air separation protects a CP4 or CP3 at increased fuel demand.
Build Guides · Power Stroke
HP Tuners Stage 1, 2, and 3 on the 6.7 Power Stroke: What Each Stage Requires
A clear breakdown of what Stage 1, 2, and 3 mean on the Ford 6.7 Power Stroke — what fuel system prerequisites each stage needs, what the 6R140 can handle, and where EGR cooler inspection fits in.
Platform Tech
Deep dives by engine and model year
Platform Tech · Cummins
2013–2024 Cummins 6.7 Model Year Guide: CP3 vs. CP4, 68RFE vs. Aisin, and What It Means for Your Build
Not all 6.7 Cummins trucks are the same. We break down which model years run CP3 or CP4, when the Aisin became available, and how those differences change the build sequence for a performance tune.
Platform Tech · Duramax
LBZ vs. LML vs. L5P Duramax: Which Generation Is Best to Build and Why
The LBZ, LML, and L5P are three meaningfully different platforms. We cover the injection pump changes, tune platform differences (EFI Live vs. HP Tuners), and why the LBZ remains a favorite for competition builds despite its age.
Platform Tech · Transmission
68RFE vs. Allison 1000 vs. 6R140: What Each Transmission Needs at Stage 2 and Stage 3
The three major HD diesel transmission platforms handle performance builds very differently. We break down where each needs a calibration recalibration, where a full rebuild becomes necessary, and what the torque ratings actually mean in practice.
Competition
Sled pull · Drag prep · Build showcases
Competition · Sled Pull
Planning a Hot Street Sled Pull Build: The 6 Systems You Have to Plan Together
A sled pull build isn't a bigger street tune. We break down the six systems — lift pump, CP3, compound turbo, trans brake, trans build, and competition tune — and why getting the order wrong wastes money and time.
Competition · Drag Prep
The 60-Foot Problem: Why Diesel Drag Racing Is a Traction Problem First
700 rwhp means nothing if the 60-foot is 2.4 seconds. We explain why traction strategy — converter lockup, shift point, launch RPM — determines ET on a diesel more than peak horsepower does.
Build Guides · Turbo
S300/S400 vs. S300/S480 vs. S366/S480: Picking the Right Compound Configuration for Your Cummins
Three compound configurations that sound similar but produce very different power bands. We explain what the inducer sizing, A/R ratio, and turbine housing selection actually mean for how the truck performs from idle to redline.
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Explore the Build Path
Deep-dive service and platform pages with the technical detail behind every build decision.
Blog FAQ
About the Blog
Who writes this and what you can expect from it.
Who writes the Drop Forged Diesel blog?+
The blog is written by the shop — the same technicians and tuners who do the builds. We don't use content writers who research diesel from the outside in. The articles come from what we see on actual trucks, what questions we hear repeatedly during consultations, and what we learn from the dyno and the track. If something appears in an article, it's because we've done it or seen it, not because it sounded right on paper.
How often is new content added?+
We add articles on a build-driven schedule — when a build, a common consultation question, or a platform problem generates something worth writing about in depth, we write it. We don't publish filler content on a weekly schedule. Quality over frequency is the approach, which means some months see multiple articles and some see none. The content we do publish is intended to be technically accurate and useful for months or years, not just during the week it was posted.
Can I use an article as the basis for a consultation question?+
Yes — that's exactly what the content is for. Read an article about CP4 failure prevention, then come in and ask us how that applies to your specific 2021 Ram 2500 with 45,000 miles and a Stage 1 tune from another shop. The articles establish the technical framework; the consultation applies it to your specific truck. We'd rather have an informed conversation that starts at the right level than spend the first 20 minutes of a consultation explaining what a lift pump does.
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THE CONSULTATION
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The blog is background. The consultation is where we look at your specific truck and build the right plan for it.
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Service Area
Diesel Performance — Houston Metro