You Have $5k To Spend Towards A Truck, How Are You Spending It?
About this episode
The Diesel Performance Podcast tackles a practical “$5k truck upgrade” question, focusing on foundation mods that improve drivability and reliability before chasing big power. They argue for tuning (single engine + trans tune where applicable), plus a lift pump and key fuel-system items like rail pressure relief/sump setups on older Duramaxes. The hosts compare 01–10 Duramax, 03–07 5.9 Cummins, and 17–23 L5P/LML strategies, including injector pigtails and when to upgrade turbos. They also call out misleading marketing claims, emphasizing real-world testing and trans tuning/valve bodies on Cummins.
Anthony Bruneni and Chris Ehmke are here with an episode on upgrades! You have $5k to spend on your truck, how are you going about picking upgrades? Truck mod paths they discuss are the 01-10 Duramax, the 3rd Gen 5.9L Cummins, the LML/L5P 6.6L, 6.7L Cummins, and 2017+ Powerstroke 6.7L.
If you had $5k to spend on your diesel truck, how are you spending it? Let us know in the comments or on our Diesel Performance Podcast Facebook page!
twin turbo kit
"Nick, you know, our old boss. He, he did this contest, right, for who could sell a twin turbo kit. This is back like 2014."
A “twin turbo kit” adds two turbochargers to the engine. That can help the truck make more power, but it usually takes more work to install and tune correctly.
A “twin turbo kit” is an aftermarket forced-induction setup that uses two turbochargers instead of one. On diesel trucks, it’s often pursued for higher airflow and stronger power potential, but it also increases complexity and demands careful supporting mods and tuning.
ball joints
"Fuck, we do your ball joints are on the parking lot, dude. Yeah. Yeah. You know, we've, we've seen some of that."
Ball joints are like pivot points in the front suspension that help the wheels move and steer properly. If they’re worn out, the truck can feel loose or unstable and the tires can wear unevenly.
Ball joints are suspension components that allow the steering knuckle to move while maintaining alignment. Worn ball joints can cause wandering, uneven tire wear, and dangerous loss of control—especially at speed or with larger tires.
CP three
"It doesn't have to work as hard and not only does the pump not have to work as hard, CP three doesn't have to work as hard, keep up with the demand."
CP3 is the engine’s high-pressure fuel pump. If the fuel coming in is easier to pull, the CP3 doesn’t have to work as hard to build the pressure the injectors need.
“CP3” commonly refers to the Bosch CP3 high-pressure fuel pump used on many diesel trucks. When the lift pump and fuel supply are improved, the CP3 can operate with less strain because it doesn’t have to compensate for restricted/low-flow supply.
EGT probe
"[791.0s] And the two to the three is a massive jump. [792.9s] No, no, it's definitely the Christmas, the operation of it. [795.8s] Yeah, throw an EGT probe in there as well. [798.2s] Like I think that could round out the dollar amount pretty quick."
An EGT probe measures how hot the exhaust gases are. If EGT gets too high, it can hurt the engine, so it’s a common safety monitor on tuned diesels.
An “EGT probe” measures exhaust gas temperature (EGT), which is a key indicator of how hard the engine is working and how close you are to overheating. Diesel tuners often recommend EGT monitoring because excessive EGT can damage components.
trans
"...it's like, hey, when are you going to do a trans? Oh, when the trans gives me an issue..."
“Trans” just means the transmission. They’re saying some people don’t upgrade it until it starts acting up.
“Trans” is shorthand for transmission. The speaker is describing a common decision point: many owners wait until the transmission shows problems before upgrading, rather than upgrading proactively.
lift pump
"Yeah. You know, little add ons to kind of put into that, you know, like, like we mentioned in the prior truck, like a lift pump, you know, the Rams do have factory lift pumps implemented, but there are updated styles that are going to be less restrictive as you want to grow in power..."
A lift pump is an extra fuel pump that helps feed diesel to the engine. When you make more power, the engine needs more fuel, and the lift pump helps make sure it gets it reliably.
A lift pump is an auxiliary fuel pump that helps supply diesel to the high-pressure system at the right pressure and flow. Upgrading a lift pump can support higher power levels by ensuring the engine has consistent fuel delivery under load.
filtration and water separation
"...you want to add the additional filtration and water separation, such as like fast air dogs, stuff like that."
Diesel can pick up dirt and water. Filters and water separators help keep the fuel clean so the engine and fuel system stay healthy.
Filtration removes contaminants from diesel, while water separation helps prevent water from reaching sensitive fuel components. When power is increased, maintaining clean, consistent fuel delivery becomes more important to avoid damage and drivability issues.
horsepower
"So, you know, maybe you only want to make 400 or 500 horsepower, maybe a year or two from now, you want to make 650 or 700."
Horsepower is how much power the engine makes. When you plan to build a truck for a certain power level, you also have to upgrade the parts that feed fuel and air so the engine can actually reach that goal.
Horsepower is a measure of engine output. In diesel performance builds, targeting a specific horsepower level helps determine what supporting upgrades (like fuel pumps and turbochargers) you’ll need to avoid bottlenecks.
air intake
"...do a lift pump, add an air intake into the mix."
An air intake helps the engine breathe easier by letting in more air. More air can help the truck make better power when you’re also adding fuel with a tune.
An air intake upgrade improves airflow into the engine, which can help a diesel make more power and respond better to tuning. It’s often paired with fueling changes so the engine has enough air to match the added fuel.
clutch
"...have a six speed manual truck where you just had to buy a clutch."
The clutch is what lets you change gears in a manual. If you make the truck stronger, the clutch may need to be upgraded so it doesn’t slip.
The clutch is the friction device that connects and disconnects the engine from the transmission in a manual truck. When torque increases from tuning or turbo upgrades, the clutch may slip or wear out, so it’s a common “first upgrade” on manual diesel builds.
turbocharger
"He goes, well, I want to see how efficient your turbocharger is compared to a competitor who advertises their product and has compressor maps."
A turbocharger is a device that uses exhaust gases to spin a fan that pushes more air into the engine. More air can mean more power, but the turbo has to be matched well to the engine.
A turbocharger uses exhaust energy to spin a compressor that forces more air into the engine. That extra airflow supports higher power, but efficiency and matching to the engine matter for real-world performance.
compressor map
"That's going to be far more important to you than a compressor map."
A compressor map is like a turbo “performance chart.” It helps predict how the turbo should work, but real-world testing can show what actually happens in an engine.
A compressor map is a chart showing a turbo’s efficiency and operating ranges for different airflow and pressure ratios. The speaker argues that real test data (EGT, drive pressure, boost, spool) can be more useful than relying only on theoretical compressor maps.
CP4 pump
"If you were on the forums and you were very scared of a CP4 pump, right?"
CP4 pump is the name of a fuel pump type. Some people worry about it because when it fails, it can cause major damage and expensive repairs.
The CP4 pump refers to a Bosch high-pressure fuel pump design used on some diesel applications. It’s become a common topic in enthusiast communities because failures can be catastrophic and are often linked to fuel contamination or poor fuel quality.
contamination issue
"it was always a contamination issue. It was always a fuel quality issue."
A contamination issue means debris, water, or other contaminants entering the fuel system. High-pressure pumps are sensitive to this, which is why contamination is repeatedly cited as the cause behind many pump failure stories.
CP4s
"Because that's another one where I've had more injector pigtail issues than CP4s. Again, it's a very different component. But with the horror stories you hear about CP4s"
CP4 is the name of a fuel pump. Some diesel owners have had bad experiences with CP4 pump failures, which is why people talk about replacing or upgrading it.
“CP4” refers to a Bosch CP4 high-pressure fuel pump used on some diesel engines. The hosts mention “horror stories” about CP4 failures, which is why many owners consider upgrades or conversions.
high flow kits
"...that are going to do tuning on an L five P four of them are doing high flow kits. You know, they're doing an air intake."
High-flow kits are aftermarket components designed to increase airflow (often intake and related piping/filters) beyond stock. On tuned diesel trucks, they’re commonly paired with tuning to better match increased fueling demands.
stock trucks
"I got customers that are out there with stock trucks. I got customers out there with tune trucks and modification."
A “stock” truck is basically how it left the factory—no performance changes. The speaker is saying that whether a truck is tuned can change how hard the transmission works.
“Stock” means the truck is running factory settings with no performance tuning or transmission calibration changes. The speaker contrasts stock trucks with “tune trucks and modification,” implying that transmission behavior and valve body wear can differ depending on how the truck is calibrated and driven.
shift schedule
"And are they the best shift schedule or shift quality and functionality trans? No, there's more refined."
A shift schedule is the programmed pattern that determines when and how the transmission changes gears. It affects shift timing, firmness, and overall drivability. The speaker is comparing shift quality/functionality between transmission options.
shift quality
"And are they the best shift schedule or shift quality and functionality trans? No, there's more refined."
Shift quality describes how smoothly and consistently a transmission changes gears under different loads. It includes factors like shift timing, firmness, and whether shifts feel controlled rather than jerky. The speaker uses it to judge transmission designs and how tuning affects real-world behavior.
WC Fab
"Chris down at WC Fab, his is stock. There's no tuning or anything."
WC Fab is a shop that works on trucks. They’re mentioned because the person’s truck is stock, meaning it hasn’t been modified with tuning.
WC Fab appears to be an aftermarket fabrication/tuning shop involved in diesel truck builds. The speaker mentions a truck that is “stock” with “no tuning,” contrasting it with what WC Fab typically does.
valve body hex bolts
"...drop the the trans pan. And there were all the valve body hex bolts. The valve body had swollen so much that it split the valve body in half."
These are the bolts that hold the valve body together. If the valve body warps or swells, the bolts can’t keep everything sealed and aligned.
Valve-body hex bolts are the fasteners that clamp the valve body plates together. If the valve body swells or flexes, these bolts can become loose or the plates can separate, leading to major hydraulic failure.
S&B
"So the S&B had the nice intake kits where they would swap a battery relocation [2368.2s] and move the intake box."
S&B is a company that makes aftermarket truck parts, especially intake systems. Their kits can include extra pieces to make the intake fit and work better.
S&B is an aftermarket manufacturer known for intake systems for trucks. When the host mentions S&B intake kits, they’re referring to a specific brand’s solution that may include hardware changes like relocating the battery and repositioning the intake box.
intake box
"So the S&B had the nice intake kits where they would swap a battery relocation [2368.2s] and move the intake box. [2369.8s] and move the intake box."
The intake box is the housing that holds the air filter and helps route air into the engine. If it’s restrictive, swapping it can help the engine get more air.
The “intake box” is the airbox/air inlet housing that sits between the air filter and the engine intake tract. On many diesel trucks, the factory airbox design can be a restriction, so changing it is part of why some intake kits claim power gains.
Ford
"And I think out of all these trucks that we're talking about, if we're talking about what's the leading contender, it's Ford. Absolutely. All day long."
They’re saying Ford is the best overall choice in this group, based on how the truck drives day to day and how well it performs.
Ford is being positioned as the “leading contender” among the major diesel pickup brands discussed. The host’s comparison focuses on real-world drivability, power delivery, and overall completeness.
proper tuning
"Like you get into those and you are not going to be disappointed with proper tuning. I mean, even if you were to get into like the 11 to 16 trucks,"
Proper tuning means setting the truck up the right way so it runs strong without feeling rough or stressing parts. It’s not just “turning it up”—it’s matching the tune to the truck.
“Proper tuning” means using a calibrated setup that matches the truck’s hardware and goals—often balancing power, drivability, and reliability. In diesel trucks, tuning quality can strongly affect throttle response, smoke control, and how hard the engine and transmission are worked.
drivability
"I'm talking purely from drivability, power delivery, and just functionality, right? Ram, if you're going to compare the Ram, like the Ram's bottom of the barrel from the power delivery,"
Drivability is how nice the truck is to drive day to day. It includes things like how it responds when you accelerate and how smooth it feels.
“Drivability” refers to how easy and pleasant the truck is to drive in real conditions—throttle response, shift feel, low-speed manners, and how it behaves during everyday driving and towing. The host uses it as a key metric alongside power delivery and functionality.
tuning definitely has the ability to improve
"Tuning definitely has the ability to improve on, but like, you know, you get guys that call in asking about what to buy,"
The host emphasizes that aftermarket tuning can meaningfully improve how a diesel truck drives and performs. This is especially relevant when comparing stock-feel differences between brands, since calibration changes can alter throttle response, torque management, and drivability.
budget builds
"So I think it's going to be fun to back into some of this stuff a little bit more and actually get into some of those budget builds."
A “budget build” means you’re upgrading a truck without spending a ton of money. The goal is to pick the upgrades that give the biggest improvement for the least cash. They’re talking about doing that kind of plan on these trucks.
“Budget builds” refers to building or modifying a truck within a limited budget, usually prioritizing the most impactful upgrades first. In diesel performance circles, that often means focusing on drivability and control (like exhaust braking) before chasing expensive power gains. The segment frames this as a fun way to revisit older “go back to the roots” modification ideas.
Request an Explanation
Heard something you'd like explained? We'll add it to this episode.
Sign in to request explanations for terms you heard.
Want to learn more?
Browse our glossary for plain-English explanations of automotive terms, jargon, and concepts.
Help improve this episode
See something that's not quite right? Our annotations are AI-generated and can sometimes miss the mark. Click the flag icon on any annotation to suggest a correction.