Why Upgrade to an H&S Motorsports Diesel Exhaust System

Diesel exhaust upgrades are one of the most effective modifications for gaining horsepower, torque, and fuel efficiency from a modern diesel truck. H&S Motorsports has built a reputation for precision-engineered exhaust components that reduce back pressure, lower exhaust gas temperatures (EGT), and deliver a deeper, more aggressive tone. When installed correctly, these systems can unlock significant performance gains while maintaining reliability. However, the difference between mediocre results and maximum performance often comes down to following a set of best practices during installation. This guide covers everything from pre-installation preparation to post-installation tuning, helping you get the most out of your H&S Motorsports diesel exhaust upgrade.

Benefits of Choosing H&S Motorsports Exhaust Upgrades

H&S Motorsports offers a range of exhaust solutions, including turbo-back, downpipe-back, and muffler delete kits for popular diesel platforms like the 6.7L Power Stroke, 6.7L Cummins, and 6.6L Duramax. The primary benefits include:

  • Reduced back pressure – Larger diameter tubing and straight-through components allow exhaust gases to exit more freely, spooling the turbocharger faster and lowering EGT.
  • Increased horsepower and torque – Most H&S systems show gains of 20–50 horsepower at the wheels, depending on the tune and supporting mods.
  • Improved fuel economy – A more efficient exhaust flow reduces the load on the engine, leading to better miles per gallon under normal driving conditions.
  • Durable construction – T304 or T409 stainless steel with mandrel bends and CNC-machined flanges ensure long life and a precise fit.

While the hardware is engineered to bolt on, achieving those claimed gains requires careful installation. A single exhaust leak or misaligned hanger can negate performance and create drivability issues.

Pre-Installation Planning and Safety

Before lifting a wrench, thorough preparation saves time and prevents damage to both the vehicle and the new exhaust components.

Tools and Materials

Gather the following tools and supplies before you begin:

  • Socket set and ratchet (metric and SAE sizes)
  • Torque wrench (capable of 50–150 ft-lb for V-bands and clamps)
  • Penetrating oil (e.g., WD-40 or PB Blaster)
  • Flathead screwdriver and pry bar
  • Exhaust hanger removal tool or pliers
  • Safety glasses and gloves
  • Floor jack and jack stands
  • New gaskets and exhaust sealant (if required by the kit)

Check the contents of your H&S Motorsports kit against the included checklist. Many kits come with new clamps, gaskets, and V-band adapters. If any hardware is missing or damaged, contact H&S support before proceeding.

Workspace Preparation

Work in a well-ventilated area with adequate lighting. If you are working indoors, ensure the overhead door is open or use a ventilation fan to clear exhaust fumes. The vehicle should be parked on level ground, and the engine must be completely cool – hot exhaust components can cause burns and make bolts difficult to remove. Disconnect the negative battery terminal to prevent any accidental short circuits or airbag deployment.

Step-by-Step Installation Guide

The following process is a general outline for turbo-back exhaust installations. Always refer to the specific instructions included with your H&S Motorsports kit, as some applications have unique steps (e.g., cutting the factory exhaust or repositioning sensors).

Removing the Factory Exhaust

Start by jacking up the vehicle and supporting it securely on jack stands. Apply penetrating oil to all exhaust bolts, clamp nuts, and hanger rubbers 15–20 minutes before loosening them. Do not use heat near fuel lines or wiring. Remove the exhaust system in sections, working from the tailpipe forward. Use a hanger removal tool to disconnect the rubber isolators without tearing them. If the factory downpipe is one piece with the catalytic converter (common on 2017+ Power Stroke trucks), you may need to cut the pipe using a sawzall with a medium-tooth blade. Cover the turbo outlet with a clean rag to prevent debris from entering the engine.

Installing the H&S Motorsports System

Begin installation at the turbo side. Apply a thin film of anti-seize to the turbo outlet studs (if applicable) and install the new downpipe or up-pipe using the supplied gasket. Snug the hardware but do not fully tighten – you need to align the rest of the exhaust first. Work your way back, loosely connecting each section: downpipe, catalytic converter (if retaining), intermediate pipe, muffler (if applicable), and tailpipe. Ensure all V-band clamps are fully seated and that the pipes do not contact the frame, driveshaft, or suspension components. Once everything is aligned, tighten all clamps to the torque specified in the instruction manual – typically 50–60 ft-lb for 4-inch V-bands. Double-check that the hangers are engaged correctly and that the exhaust tips sit evenly in the bumper cutout.

Torque Specifications and Hardware

Using a torque wrench is critical. Under-tightening can cause exhaust leaks and rattling; over-tightening can strip threads or crack flanges. H&S Motorsports recommends the following general torque values (verify your kit):

  • Downpipe bolts: 35–40 ft-lb
  • V-band clamps (4-inch): 50–60 ft-lb
  • Muffler/tip clamps: 20–25 ft-lb
  • Oxygen sensor (if relocated): 30 ft-lb

After tightening, inspect each connection visually for gaps. A flashlight can help spot misalignments.

Connecting to the Turbo Downpipe

On many H&S systems, the downpipe flange uses a bellows-style flexible section to accommodate engine movement. Ensure the bellows is not compressed or stretched during installation – it should be at its free length. If the downpipe has a port for an EGT probe, install the probe before the downpipe is fully tightened. Use a back-up wrench on the probe hex to avoid twisting the thermocouple wires.

Performance Tuning and Calibration

Installing a full exhaust system changes the engine’s airflow dynamics significantly. Without proper calibration, the engine control module (ECM) may not deliver the correct fuel-air mixture, leading to reduced performance or even diagnostic trouble codes (DTCs). H&S Motorsports offers tuning solutions that work hand-in-hand with their exhaust upgrades.

ECM Remapping Requirements

Most H&S exhaust kits are sold with or recommended to be used with an H&S tuner, such as the XRT or MC2. Loading a tune specifically designed for the exhaust system ensures the ECM adjusts fuel timing, injection pressure, and boost targets to match the lower back pressure. Running an aftermarket exhaust without a tune can cause the engine to run lean on older trucks or over-fuel on newer emissions-equipped trucks, potentially raising EGT to dangerous levels.

Monitoring EGT and Boost

After the tune is installed, monitor exhaust gas temperature and turbo boost pressure during the first few drives. Diesel engines operate safely at EGTs below 1,300°F (continuous) and 1,500°F (peak). If you do not have a gauge, install an aftermarket EGT probe in the exhaust manifold or turbo discharge pipe. H&S Motorsports’ kits often include bungs for sensor placement. Never exceed 1,400°F for more than 10 seconds – this can cause piston and turbine damage.

Post-Installation Procedures

A successful installation goes beyond bolting up the pipes. Follow these steps to confirm everything is working correctly.

Leak Detection and Final Checks

With the engine at idle, listen for hissing sounds around all connections. Use a soap-and-water spray bottle to test for air bubbles at gaskets and V-band clamps. A small leak can worsen over time and cause a false reading from oxygen sensors. Also verify that the exhaust does not contact the starter, oil pan, or crossmember. Shift the transmission into drive and reverse (while stationary) to check for clearance under load. Re-torque all clamps after 100–200 miles, as thermal cycling can loosen hardware.

Break-In Period Guidelines

New exhaust systems require a short break-in period for gaskets to seat and metal surfaces to normalize. For the first 500 miles:

  • Avoid sustained heavy throttle or towing at maximum load.
  • Allow the engine to warm up to operating temperature before exceeding 2,500 RPM.
  • Vary engine speed during highway driving – do not hold a steady cruise for extended periods.
  • Inspect the system after the first heat cycle for any loose clamps or rubbing.

Maintenance and Long-Term Care

Maintaining your H&S Motorsports exhaust system ensures it continues to deliver maximum performance and sound.

Inspection Schedule

Every 5,000 miles or at each oil change, inspect the entire exhaust system:

  • Look for rust or pitting, especially at welds and hangers.
  • Check that all V-band clamps are tight (they should not spin freely).
  • Verify that the exhaust hanger rubbers have not dried out or cracked.
  • Examine the exhaust tip for carbon buildup – heavy soot may indicate an overly rich tune.

Cleaning and Rust Prevention

If your system is made from T304 stainless steel, it resists corrosion, but road salt and dirt can still cause surface stains. Wash the underside of the truck periodically. For polished tips, use a stainless steel cleaner and a microfiber cloth. Avoid using abrasive pads that can scratch the finish. Never apply paint or coatings to the exhaust system unless specifically approved by H&S – the heat can cause off-gassing that smells unpleasant.

Common Installation Mistakes to Avoid

Even experienced DIYers can overlook details that compromise performance. Steer clear of these pitfalls:

  • Skipping the tune – Installing an exhaust without updated ECM calibration is the most common reason for no performance gain or high EGT.
  • Forgetting new gaskets – Reusing old gaskets (especially the turbo-to-downpipe gasket) almost guarantees a leak.
  • Over-tightening V-bands – This can deform the clamp collar, causing an uneven seal. Use a torque wrench.
  • Routing the exhaust too close to wiring or fuel lines – Heat can damage insulation. Maintain at least 2 inches of clearance.
  • Ignoring exhaust hanger orientation – Some hangers are directional. Installing them backward puts stress on the pipe and can cause rattling.
  • Not reconnecting the battery correctly – Some vehicles require a specific sequence to reset the ECM. Consult your owner’s manual.

Diesel exhaust modifications may impact vehicle emissions compliance. H&S Motorsports exhaust kits are designed for off-road or competition use only unless certified for on-highway use in your region. Removing the diesel particulate filter (DPF) or catalytic converter is illegal in many jurisdictions, including most U.S. states, and can result in fines or failed inspection. Before installing, check local laws. The EPA’s Clean Air Act prohibits tampering with emissions control systems. H&S offers DPF-back systems that retain the filter while still providing flow gains, which may be a legal alternative. Always verify that your tuning also complies – some tuners offer “street-legal” tunes that keep emissions systems operational.

Conclusion

Installing an H&S Motorsports diesel exhaust upgrade is a rewarding project that can transform the performance of your truck – but only if done correctly. By preparing properly, following torque specifications, pairing the exhaust with an appropriate tune, and performing regular maintenance, you will maximize horsepower, improve fuel economy, and enjoy a reliable exhaust system for years. Take the time to do it right the first time, and you will feel the difference from the moment you press the throttle. For more detailed technical information, visit the H&S Motorsports official website or consult community forums like Diesel Power Magazine for real-world installation stories.