Nashville’s performance car scene is as diverse as its music lineup—from turbocharged imports ripping through downtown streets to LS-swapped muscle cars hunting apexes at Music City Motorplex. No matter the build, one overlooked upgrade that consistently pays dividends is a well-sorted catch can system. A generic off-the-shelf unit might work for a daily commuter, but for a high-horsepower street machine or a time-attack weapon that sees stop-and-go traffic and sticky Tennessee summers, customization is key.

This guide dives deep into tailoring your catch can setup for the unique demands of Nashville driving—covering climate, driving styles, engine modifications, and installation best practices that go beyond the basics. By the end, you’ll have a clear path to building a catch can system that keeps your intake valves clean, your oil vapor properly separated, and your engine running at its peak.

What a Catch Can Really Does (And Why You Need It)

Your engine’s crankcase ventilation system (typically the PCV valve) routes blow-by gases—a mix of unburned fuel, combustion byproducts, oil mist, and moisture—back into the intake tract. While that keeps emissions in check, it also sends a sticky film of oil and carbon straight onto your intake valves and intercooler piping. Over time, that buildup robs power and can lead to detonation or even valve seal failure.

A catch can sits between the valve cover and the intake manifold, physically separating the liquid and solid contaminants from the air before it re-enters the intake. It’s a simple device, but its effectiveness depends on design, placement, and integration with your specific engine setup. For Nashville builds—whether naturally aspirated or forced induction—a one-size-fits-all catch can often falls short, especially when you factor in our climate and driving conditions.

Nashville’s Unique Challenges: Heat, Humidity, and Stoplight Jousting

Nashville’s environment is no joke for engine systems. Summer heat indexes regularly push past 100°F, with relative humidity often above 70%. That combination does two things to your crankcase ventilation:

  • More oil vapor: High ambient temperatures heat up the engine oil faster, increasing oil vaporization. The hotter the oil, the more vapor gets sucked into the PCV stream.
  • More moisture: Humidity means more water vapor condenses in the intake and crankcase. Without efficient separation, that moisture bypasses the catch can and mixes with oil, forming sludge and acidic compounds that accelerate wear.

On top of climate, the typical Nashville driving cycle includes long idles in rush-hour traffic on I-440, aggressive pulls on empty backroads, and weekend laps at the track. Each mode creates different crankcase pressure and airflow. A static catch can setup might work well at cruising but fail under WOT—or vice versa.

Customization Options That Actually Matter

Moving beyond the basic can, here are the critical parameters to optimize for Nashville performance builds.

Size and Capacity

The bigger the engine and the more aggressive the driving, the more blow-by you generate. A 1-liter can might be fine for a stock EcoBoost Mustang, but a turbocharged 2JZ or a 6.2L LS running 15 psi will fill that can in a day of hard driving. Go with at least a 1.5-liter can for moderate builds and 2–3 liters for race or high-horsepower street cars. Nashville’s humidity also means extra liquid volume from condensation—oversizing provides a safety margin.

Material Selection

Aluminum and stainless steel are the standard choices. Aluminum is lighter and dissipates heat well, which helps cool the vapors and promote condensation. Stainless steel is more corrosion-resistant and easier to clean, but heavier. For a street-driven car that sees salt in winter (yes, Nashville gets a few snow events), stainless is better long-term. If you’re weight-conscious on a track car, go with anodized billet aluminum.

Baffling and Internal Design

This is where most generic catch cans fail. A simple open chamber does a poor job of separating oil mist—it relies on gravity alone. Look for a design that uses baffles, a labyrinth, or a filter medium (like mesh or glass wool) to force the air to change direction multiple times, dropping out the liquid. For high-humidity environments like Nashville, a coalescing filter-style can (e.g., using a stainless steel mesh packing) is more effective at trapping moisture.

Drainage System

A petcock valve at the bottom is the minimum, but if your can is mounted in a tight engine bay, you’ll curse every time you have to drain it. Install a remote drain hose with a ball valve reachable from the top or side of the engine bay. For track cars, consider a quick-disconnect drain fitting so you can empty the can between sessions without tools.

Filter Additions

Some catch cans include an internal filter or a replaceable element. If you go that route, make sure the filter is easy to service—cleaning or replacing a clogged filter restores flow and separation efficiency. For Nashville’s humid air, a filter can help capture moisture that would otherwise condense inside the can walls and get carried downstream.

Check Valves and Restrictors

PCV systems rely on a calibrated vacuum signal. If you’ve modified your engine (e.g., larger cam, forced induction), the stock PCV valve may not control flow properly. Adding a one-way check valve in the hose between the valve cover and catch can prevents backflow under boost. A restrictor orifice (e.g., 0.060–0.090 inches) can tune the flow rate to keep crankcase pressure under control without sucking too much oil.

Installation Best Practices for Reliable Performance

Even the best catch can will disappoint if installed haphazardly. Follow these guidelines to ensure longevity and effectiveness.

Mounting Location

Mount the catch can as low as practical—gravity helps liquids settle. Avoid placing it near exhaust manifolds or turbo downpipes; excessive heat re-vaporizes the collected oil and reduces separation. Aim for a spot with good airflow (like near the radiator or fender well) to keep temperatures down. Also consider access: you need to drain it regularly, so don’t hide it behind the intake manifold.

Hose Routing

Use reinforced hoses rated for oil and temperature (e.g., 200°F or higher minimum). Avoid nylon or cheap fuel line—they’ll harden and crack in a year. Route hoses so they have a gentle, continuous downward slope toward the catch can to allow gravity drainage. If you must run a hose uphill, the can will fill with liquid and lose capacity. Keep hoses away from moving parts and hot surfaces—use fire sleeve if necessary.

Secure Mounting

Vibration can loosen a catch can bracket over time, leading to rattles or a disconnected hose. Use rubber isolation mounts to dampen vibration and lock washers on all bolts. For heavy cans (2L+), consider a second support bracket.

Regular Maintenance

Inspect and drain the catch can every 1,000 miles or after every track day—whichever comes first. In Nashville’s humid summer, you may need to drain it more frequently because of condensed water. Clean the internal baffles and replace filters (if applicable) at every oil change. A neglected can that’s full to the brim will let liquid bypass back into the intake—defeating the purpose.

Advanced Configurations for Forced Induction and Dedicated Track Cars

Nashville is home to a thriving turbo and supercharger community. Boosted engines place extreme demands on the PCV system.

Dual Catch Can Setup

Many turbo builds run two cans: one on the PCV side (intake manifold vacuum) and one on the breather side (valve cover to intake pipe). During high boost, crankcase pressure vents through the breather side, and a dedicated catch can there prevents oil from coating the intercooler and charge pipes. For street-driven cars, a dual setup is the gold standard.

Vacuum Pump Integration

Race engines often use an electric or mechanical vacuum pump to pull a negative pressure in the crankcase, reducing windage and increasing ring seal. A catch can is essential before the vacuum pump to protect it from oil ingestion. Customizing the can’s port size and internal baffling is critical here—pumps generate high flow rates.

Closed vs. Open Ventilation

In most street cars, the PCV system is closed—everything vents back into the intake. But some high-performance builds run an open breather setup with a catch can vented to atmosphere. This reduces vacuum fluctuations but can emit oil smell and is not legal for emissions in some states. For track-only cars, it’s a viable option. Nashville’s humidity makes closed systems better because they keep moisture from condensing in the crankcase.

Troubleshooting Common Catch Can Issues

  • Can fills too fast: Check for excessive blow-by (worn rings or seals) or an oversized PCV orifice. Add a restrictor or upgrade your baffles.
  • Oil still makes it into the intake: Your can may lack proper internal baffling. Replace with a labyrinth-style design. Verify hose routing—if the can is higher than the valve cover, liquid can siphon.
  • Vacuum leaks or rough idle after install: Ensure all connections are tight and the PCV valve is functioning. A stuck-open check valve can cause unmetered air.
  • Frozen or clogged drain valve in winter: Water condensation can freeze. If you drive in winter, use a can with a heat trace or drain after every drive. Or switch to a stainless steel can with a ball valve that can be forced open if needed.

Conclusion: Build a Catch Can System That Matches Your Nashville Build

Customizing your catch can setup isn’t about following a generic guide—it’s about engineering a solution that fits your engine, your driving style, and the environment you operate in. Nashville’s heat, humidity, and mix of street and track driving demand a thoughtful approach to size, materials, baffling, and installation.

Start by evaluating your current setup. Are you draining more water than oil? Is your can filling too fast? Use the guidelines above to make targeted upgrades. For parts and additional reading, check out resources from Radium Engineering or Summit Racing’s tech articles—both offer deep dives into PCV system tuning. And if you’re in the Nashville area, many local speed shops can help you source the right components and even custom-fabricate brackets for your specific chassis.

With a properly tailored catch can, you’ll keep your intake valves clean, your engine oil free of moisture-laden sludge, and your performance consistent—no matter how hard you drive it. That’s the kind of reliability that wins at the track and the streetlight.