Deleted and Tuned L5P Horsepower: HP Gains and Tuning Guide

If you're considering deleting and tuning your 2017-2026 Duramax L5P, the horsepower potential is probably the first thing you want to know. So how much HP does a deleted and tuned L5P make?

A deleted and tuned 2017-2023 L5P Duramax produces 545-600+ rear-wheel horsepower (RWHP) on a performance tune with documented pulls reaching 594 RWHP and 1,281 lb-ft of torque - well above the stock 380-400 RWHP baseline. Supporting mods and transmission tuning push reliable numbers to 650+ RWHP at the wheels. That's a gain of 165-200+ whp over stock, depending on your tune level and supporting modifications.

The L5P Duramax - GM's 6.6L V8 diesel found in 2017+ Chevy Silverado 2500/3500HD and GMC Sierra 2500/3500HD trucks - is the most powerful Duramax from the factory yet. But the emissions equipment strapped to it chokes its real potential. Removing the EGR, DPF, DEF, and SCR systems and reflashing the ECM with a custom calibration unleashes the engine's full output. The result is a truck that pulls harder, tows cooler, and puts down numbers that rival older modified Duramax platforms with far less effort.

In this guide, we break down the actual dyno results, explain what each component of a full delete contributes to the horsepower equation, and show you exactly what to expect from an L5P delete and tune - whether you're looking at a mild street setup or an all-out race build.

What Does a Deleted and Tuned L5P Make on the Dyno?

A properly deleted and tuned L5P produces 545-600+ horsepower depending on tune level and supporting hardware, with real dyno pulls reaching 594 RWHP and over 1,281 lb-ft of torque on the rear wheels.

Let's start with the numbers that matter - actual dyno results from real shops and tuners who have tested the L5P after a full delete and tune.

L5P Stock Baseline Numbers

Before we talk gains, you need to know where you're starting from.

Here are the stock dyno numbers for the L5P by model year:

Model Year	Stock Crank HP	Stock Crank Torque	Stock Wheel HP (Dynojet)
2017-2023 L5P	445 HP	910 lb-ft	~380-410 whp
2024-2026 L5P	470 HP	975 lb-ft	~410-420 whp

Pushing stock L5P internals past 600 wheel horsepower begins testing the torque limits of the factory Allison 10L100 transmission and stock torque converter clutch. To review engine block structural updates, fuel injection pump pressures, and drivetrain limits across model years, explore our detailed 15p duramax guide.

Deleted and Tuned L5P Dyno Results

Here's what a deleted and tuned L5P actually puts down, based on shop dyno sheets and tuner data:

Shop / Source	Setup	Wheel HP	Wheel Torque	Notes
PPEI	"All Purpose" tune + Banks intake	544 HP	1,051 lb-ft	Tow-safe calibration
DuramaxTuner	Top-level race tune	595 HP	1,180 lb-ft	+150 whp over stock
EGR Performance + Calibrated Power	Stage 2 build, 2025 L5P	603 HP	-	Full EGR Performance exhaust + tune
Edge Pulsar / Insight	Full delete + max race tune	640+ HP	1,250+ lb-ft	Stock turbo and fuel
Banks Power	Built fuel + turbo, stock block	1,004 HP	-	Engine dyno, not wheel

By Tune Level (RWHP)

Tune Level	Crank HP	RWHP (Wheels)	Torque (lb-ft)	Primary Use
Street / Eco	545	450-470	950-1,000	Daily driving, best MPG
Performance	595	490-510	1,050-1,100	Towing and spirited driving
Max Effort / Race	645+	540-560	1,150-1,280+	Competition, max unloaded power

The takeaway is consistent: a proper L5P delete and tune puts you in the 550-600+ whp range on pump fuel with a street-oriented calibration. If you push the tune harder, 640+ whp is achievable while still running the stock CP4 fuel pump and factory turbocharger.

Before putting down over 550 to 650 wheel horsepower on the rollers, unlocking the factory-encrypted engine control module is the necessary first step to allow custom parameter recalibration.

The real magic is the area under the curve. Deleted L5Ps make strong torque from 1,000 RPM and hold it longer because the factory torque management is gone. Towing 15,000 pounds up a 6% grade feels effortless compared with stock.

L5P Delete HP Gains by Stage

Stage 1 (EGR/DPF delete + basic tune) adds 100-150 HP. Stage 2 (full hardware support + transmission tuning) pushes past 500 RWHP. Stage 3 (tuned turbo and injectors) delivers 600+ RWHP.

Not every deleted L5P is built the same. The horsepower you get depends heavily on your tune level and how many supporting mods you've added. Here's how the typical stages break down:

Stage 1: Tune Only (No Delete)

Metric	Result
Wheel horsepower	~500-530 whp
Wheel torque	~1,000-1,050 lb-ft
Gain over stock	+100-130 whp
Emissions equipment	Fully intact

A tune-only L5P is surprisingly potent. The ECM recalibration alone adds significant power by increasing fuel delivery, boost pressure, and timing. You keep all emissions equipment, so this is the most legally straightforward option. The tradeoff is that the DPF still restricts exhaust flow, and the truck still goes through regeneration cycles, which interrupts power delivery.

Stage 2: Full Delete + Street Tune

Metric	Result
Wheel horsepower	~530-570 whp
Wheel torque	~1,100-1,200 lb-ft
Gain over stock	+140-180 whp
Supporting mods	None required (optional exhaust, intake)

This is where the L5P Duramax delete HP gains really start to show. A full EGR, DPF, DEF, and SCR delete combined with a moderate street tune gives you a truck that's dramatically more responsive, eliminates regeneration cycles, and drops EGTs significantly. Most daily-driven deleted L5P trucks fall into this category.

Stage 3: Full Delete + Race Tune

Metric	Result
Wheel horsepower	~570-640+ whp
Wheel torque	~1,200-1,300+ lb-ft
Gain over stock	+180-260+ whp
Supporting mods	Recommended: lift pump, exhaust, downpipe

A max-effort L5P delete tune pushes the stock turbo and fuel system to their limits. SPE Tuner has documented 640+ whp on a fully deleted L5P with the factory CP4 and turbo still in place. At this level, you should consider a FASS or AirDog lift pump, a CP3 conversion, and upgraded transmission components to handle the power reliably.

What Gets Deleted: Components That Unlock L5P Horsepower

Deleting the EGR valve, DPF, and DEF/SCR system is the foundation of every high-horsepower L5P build. These components create massive restriction and torque management.

Understanding what each deleted component contributes to the power equation helps you decide what's worth doing. Here's a breakdown:

Component	What It Does	HP Impact of Removal
EGR System	Recirculates exhaust gas back into intake	Frees up intake flow, reduces soot contamination
DPF (Diesel Particulate Filter)	Traps soot in a honeycomb filter	Eliminates backpressure, removes regeneration cycles
SCR/DEF System	Injects urea to reduce NOx emissions	Removes exhaust restriction, frees up exhaust flow
DOC (Diesel Oxidation Catalyst)	Oxidizes CO and hydrocarbons	Opens up exhaust diameter at the downpipe

The single biggest horsepower unlock comes from the tune itself - the ECM recalibration is what actually adds fuel and boost. But the delete hardware is what allows the engine to breathe freely enough to make that additional power efficiently and safely. Without the deletes, the DPF creates enough backpressure to limit how much power the tune can safely produce.

CAN BUS Protection

Open connectors from deleted components are prone to corrosion. We always recommend a high-quality CAN BUS plug kit. It seals the connections and prevents electrical issues that can throw codes or cause limp mode.

These three deletes combined with the ECM unlock are what turn the L5P into a 550+ HP truck. Anything less and the gains stay modest.

For 2020-2022 6.6L Duramax L5P owners, check this 2020-2022 L5P CAN Bus Plugs.

How Much HP Does a Deleted L5P Make on Stock Internals?

On stock internals with a full delete and tuned tune, a 2017-2023 L5P reliably makes 550-650+ RWHP. The Denso HP4 injection pump and robust bottom end support these numbers without major upgrades.

This is one of the most frequently asked questions in the Duramax community, and the answer might surprise you. The L5P's stock bottom end is remarkably robust.

Banks Power systematically tested a stock L5P Duramax to destruction in their "Killing a Duramax" series. The result? 1,004 HP on the engine dyno - with the factory block, crankshaft, connecting rods, and pistons all still in place. The stock bottom end held together at power levels far beyond what any street-driven truck would ever see.

Here's where the real limitations lie:

Component	Approximate Limit	What Happens
Stock CP4 fuel pump	~550-600 whp	Runs out of fuel volume; rail pressure drops
Stock injectors	~600 whp	Duty cycle maxed out; can't deliver more fuel
Stock turbocharger	~550-700 whp	Compressor maxed at ~135,000 rpm (Banks testing)
Stock bottom end	1,000+ HP	Proven by Banks Power; not the weak link
Stock Allison 10L1000	~500-550 whp	Starts slipping; torque converter is weak point

When you're looking at L5P deleted and tuned horsepower, the engine itself is not your concern. The fuel system, turbo, and transmission will all run out of capacity before the bottom end shows any signs of stress. For builds targeting 550-600 whp, the stock bottom end is more than adequate.

Popular Tuners and Platforms for L5P Delete Tuning

The best platforms for L5P delete tuning are EZLynk, EFI Live with AutoCal, and HP Tuners with custom files. These tools unlock the ECM and deliver proven calibrations that support 550+ HP reliably.

The tuner you choose has a direct impact on the horsepower your deleted L5P produces. Not all tunes are created equal - calibrators differ in how aggressively they push fuel, timing, and boost.

Tuner / Platform	Years Supported	Key Details
HP Tuners (MPVI3 / RTD4)	2017-2026	Dominant L5P platform; requires ECM unlock
EFI Live (Autocal V3)	2017-2023	Limited L5P support; not available for 2024+
EZ Lynk	2017-2023	Cloud-based tuning delivery
Edge Products EZ Module	2017-2025	Plug-and-play; ~80-90 HP gain, no ECM unlock needed

Trusted calibrators who build the actual tune files:

PPEI (Power Performance Enterprises Inc.)

Industry standard led by Kory Willis, renowned for consistent, reliable power delivery and safe, tow-ready calibrations designed for seamless drivability.

DuramaxTuner / Calibrated Power

Specialists in advanced custom ECM calibrations for platforms like the L5P, documented to push up to 595 wheel horsepower while maintaining strict emissions compliance.

Edge Products

Widely known for high-performance inline modules (such as the Pulsar) and Insight monitors, focusing on safe, emissions-compliant power upgrades for daily driving and towing.

Banks Power

A legendary name in the diesel performance community. Their Derringer inline tuner is highly praised for real-time OBD-II monitoring and built-in ActiveSafety safeguards to protect both the engine and transmission under heavy loads.

Supporting Mods That Maximize L5P Delete HP

Cold air intake, high-flow downpipe, CCV reroute, and TCM tuning push reliable power past 600 RWHP while keeping EGTs manageable.

A deleted and tuned L5P can make great power on its own, but supporting modifications help you push further and do it more reliably. Here are the mods that matter most:

Modification	Purpose	Price Range	HP Impact
FASS/AirDog Lift Pump	Better filtration, stable rail pressure	$400-$800	Supports tunes above 500 whp
CP3 Conversion Kit (S&S Diesel)	Replaces CP4, increases fuel volume	$1,000-$1,650	Required past ~600 whp
5" Straight Pipe Exhaust	Maximum exhaust flow	$300-$800	Supports all power levels
3.5" Downpipe	Frees up post-turbo flow	$200-$500
Cold Air Intake (S&B, Banks)	Improved airflow	$250-$400	~10-20 whp on tuned trucks
Transmission Build	Holds elevated power	$3,000-$6,000+	Required above 550 whp
Triple-Disk Torque Converter	Prevents converter slip	$800-$1,500	Required above 550 whp

To sustain peak horsepower during extended dyno runs without thermal throttling, upgrading the restrictive cast intake horn and installing a high-flow cold air intake is vital.

Intake Gains: A quality cold air intake (S&B or K&N) reduces intake air temperature by 20-30 F and adds 10-20 HP on a tuned truck while lowering EGTs under hard acceleration.

The EGR Performance L5P performance parts collection provides the foundation, but these supporting mods are what take a deleted L5P from "strong" to "unreal." Discover top-rated airflow upgrades, transmission coolers, and durability components in our guide to the best l5p upgrades.

L5P Delete and Tune Cost vs. Horsepower

A complete L5P delete and tune package costs $3,300-$4,800 and delivers 550-650 RWHP. The return on investment is measured in performance, MPG, and daily drivability.

Understanding the cost-to-power ratio helps you decide how far to take your build:

Setup	Typical Cost	Wheel HP	Cost per Added HP
Stock L5P	-	~380-420 whp	Baseline
Tune only (no delete)	$500-$1,200	~500-530 whp	~$6-10/HP
Full delete + street tune (DIY)	$1,500-$3,500	~530-570 whp	~$8-15/HP
Full delete + street tune (shop)	$3,500-$7,500	~530-570 whp	~$18-30/HP
Full delete + race tune + supporting mods	$5,000-$12,000	~600-640+ whp	~$15-25/HP
Max effort (built trans, CP3, turbo)	$15,000-$25,000+	~700-1,000+ HP	~$25-40/HP

The 2024-2026 L5P delete costs are significantly higher due to the E42 ECM unlock requirement, with some owners reporting $7,000-$9,500 for a full shop-installed delete and tune.

The 2024-2026 L5P trucks use the E42 Global B ECM, which requires a physical ECM removal and mail-in unlock service. This adds cost and complexity compared to the 2017-2023 trucks, which use the easier-to-unlock E41 ECM. For more details, see our guide on the cost to delete an L5P Duramax.

Common Problems When Pushing L5P Delete Horsepower

Common problems after delete and tune include clutch slip, high EGTs, and black smoke. Proper transmission tuning and supporting mods prevent 95% of these issues.

Going fast isn't free. Here are the issues that come up most often when pushing a deleted and tuned L5P to its limits:

CP4 Fuel Pump Failure

The factory CP4 high-pressure fuel pump has a documented 5-7% failure rate. When it fails, metal debris contaminates the entire fuel system - injectors, rails, lines, and tank - often resulting in an $8,000-$12,000+ repair bill. A FASS or AirDog lift pump with proper filtration, along with fuel lubricity additives, is cheap insurance.

Allison 10L1000 Transmission

Above 500-550 whp, the stock Allison transmission starts to slip. The torque converter is the primary weak point. Custom transmission tuning (increased line pressure) helps, but for sustained high-power use, a triple-disk converter and upgraded clutch packs are necessary.

2024+ ECM Unlock Complexity

The 2024-2026 L5P uses the E42 Global B ECM, which cannot be unlocked via the OBD2 port like the older E41. You must physically remove the ECM and send it in for an unlock service (24-72 hour turnaround). This adds cost and downtime to the delete process.

Turbo and Cooling Considerations

At elevated power levels, the stock turbo operates closer to its surge line, and coolant system capacity can become marginal under sustained heavy towing. Monitoring EGTs and boost pressure becomes more important the further you push the tune.

Frequently Asked Questions

How much HP does a deleted and tuned L5P make?

A fully deleted and tuned L5P Duramax typically produces 550-600+ whp on a street performance tune. Max-effort builds on stock fuel and turbo have been documented at 640+ whp. On an engine dyno with supporting fuel and turbo modifications, the stock L5P block has produced over 1,000 HP.

What's the max HP on a completely stock L5P engine?

Banks Power proved the stock L5P bottom end holds over 1,000 HP on an engine dyno. The limiting factors are the fuel system (CP4 pump, injectors), turbocharger, and transmission - not the engine block, crank, rods, or pistons.

Does the 2024+ L5P make more power when tuned?

Almost identical peak numbers to 2017-2023 models because the turbo is the limiting factor.

Is 600 HP safe on a stock L5P?

The engine can handle it, but the transmission cannot. The stock Allison 10L1000 is safe to about 500-550 whp. Above that, you need a triple-disk torque converter and upgraded clutch packs at minimum. The stock CP4 fuel pump also becomes a liability above 550 whp.

What happens if I skip TCM tuning on a 2020+ L5P?

Clutches will slip under hard throttle. Expect transmission failure within a few thousand miles.

Do I need head studs for a 650 RWHP L5P?

No. The L5P bottom end is extremely strong. Head studs become necessary only after 700+ RWHP with a big turbo.

Do I need a lift pump upgrade to reach 600 RWHP?

No. The factory system supports it comfortably. A lift pump becomes necessary only for 700+ HP competition builds.

What's the best tuner for a deleted L5P?

HP Tuners (MPVI3 or RTD4) is the dominant platform for L5P tuning. For calibrations, PPEI and DuramaxTuner are consistently the most recommended, with SPE Tuner being the go-to for max-effort builds.

How much does it cost to delete and tune an L5P?

DIY full delete + tune runs $1,500-$3,500 in parts. Professionally installed, expect $3,500-$7,500 for 2017-2023 trucks and $5,000-$9,500 for 2024-2026 trucks due to the more complex ECM unlock process.

Can you daily drive a deleted L5P?

Many owners do. A deleted and tuned L5P on a moderate street tune (530-570 whp) makes an excellent daily driver. The elimination of regeneration cycles, reduced EGTs, and improved throttle response actually improve the driving experience. The main considerations are legal compliance and emissions testing in your state.

Will my fuel economy drop on the max-effort tune?

No if you keep the pedal light. Many owners see better highway MPG on the highest tune because injection timing is optimized.

Is an aftermarket cold air intake necessary?

Not required, but it adds measurable power and lower EGTs. The factory intake already flows well.

Does a 5-inch exhaust make more horsepower than 4-inch?

No noticeable gain until you exceed 650 RWHP. A 4-inch system is plenty for 550+ HP.

Conclusion

So what kind of horsepower can you expect from a deleted and tuned L5P? On a street tune with a full delete, 550-600 whp is the realistic target - a gain of roughly 150-240 whp over stock. Push the tune to max effort and you'll see 640+ whp while still running the factory turbo and fuel pump. And if you're willing to upgrade the fuel system, turbo, and transmission, the stock L5P block has been proven to hold over 1,000 HP.

A deleted and tuned L5P Duramax makes serious horsepower - 550-650+ RWHP is the new normal in 2026 with the right setup. The platform responds exceptionally well to the delete, ECM unlock, and custom calibration.

The L5P Duramax is, without question, the most capable platform GM has ever put in a heavy-duty truck. A full delete and tune unlocks its full potential while simultaneously improving reliability by eliminating the most failure-prone emissions components. Whether you're towing heavy, building a street truck, or chasing dyno numbers, the L5P has the foundation to deliver.

Ready to get started? Check out the EGR Performance L5P delete kit collection for everything you need, or read our guide on the best L5P delete kits for 2026 to find the right setup for your truck.

More Reading

• L5P Tuning
• Cracking The Uncrackable L5P Duramax
• Reasons Why You Shouldn't Delete Your L5P Duramax's DPF