Frequently Asked Questions About Volvo VNR Chrome Stacks & Tops

What exhaust stack sizes and configurations fit the Volvo VNR, and how do I measure for proper fitment?

The Volvo VNR typically accommodates 5-inch diameter exhaust stacks, though some models can handle 6-inch or 7-inch stacks with proper brackets. To measure for fitment, check your existing exhaust outlet diameter at the connection point and measure the clearance between your cab and any fairings. Most VNR models from 2018-2024 have similar mounting points, but always verify your specific truck's exhaust configuration. Stack lengths generally range from 36 to 72 inches, with 48-60 inches being most common for the VNR's cab height.

Are these chrome stacks made from 304 or 409 stainless steel, and what's the difference in durability?

Most quality chrome stacks for the VNR are made from either 304 or 409 stainless steel. 304 stainless offers superior corrosion resistance and maintains its mirror finish longer, making it ideal for show trucks or harsh weather conditions. 409 stainless is more affordable and still provides good durability but may show some surface rust over time, especially in salt-heavy environments. Both materials are significantly more durable than chrome-plated mild steel. Look for stacks with at least 16-gauge thickness for optimal longevity.

Do I need special brackets or modifications to install chrome stacks on my VNR?

Most chrome stack installations on the VNR require stack clamps and possibly new mounting brackets, depending on your current setup. Standard installations typically take 2-4 hours and require basic tools including wrenches, a drill for any new mounting holes, and exhaust clamps. Some installations may need exhaust flex pipe or reducers if changing diameter sizes. No cutting or welding is usually required for bolt-on stack kits designed specifically for the VNR.

What's the difference between curved, straight, and miter cut stack tops for the VNR?

Straight cut tops provide maximum exhaust flow and a classic look, while miter (angle) cut tops direct exhaust away from the truck and create a more aggressive appearance. Curved or turnout tops offer the best rain protection and direct exhaust completely away from your trailer. For VNR models with DEF systems, curved tops help prevent exhaust residue on cab surfaces. Bull hauler style tops add extra length and are popular for their distinctive sound. Consider your typical routes and weather conditions when choosing.

Will aftermarket chrome stacks affect my VNR's warranty or emissions compliance?

Installing chrome stacks that maintain the same diameter and don't alter the exhaust system before the DPF/SCR components typically won't affect your warranty or emissions compliance. However, always verify with your dealer before installation. Ensure any stack you choose doesn't create excessive backpressure, which could trigger fault codes. Most bolt-on chrome stacks and tops are considered cosmetic modifications and are legal in all 50 states as long as they don't bypass or modify emission control devices.