Benelli TNT125 TNT135 Tornado +TNT Naked De Cat Down-Pipe Exhaust header

The benelli tnt125 tnt135 tornado +tnt naked de cat down-pipe exhaust header is one of the most effective performance upgrades you can bolt onto your Benelli small-displacement naked or roadster, freeing up the exhaust flow that the restrictive factory pipework holds back. At Max Torque Cans, we design and manufacture this header in-house using premium 304 grade stainless steel, giving you a product that is built to last, looks superb, and makes an immediate, noticeable difference to the way your bike pulls through the rev range. Whether you ride a TNT125, TNT135, Tornado, or the +TNT Naked variant, this header is the logical first step on your performance journey.

Why Choose the Benelli TNT125 TNT135 Tornado +TNT Naked De Cat Down-Pipe Exhaust Header?

The standard down-pipe fitted to these Benelli models is engineered with emissions compliance as its primary goal. That means it is packed with catalytic material and restrictive bends that choke the engine before the exhaust gases have even reached the silencer. By replacing the factory pipe with our benelli tnt125 tnt135 tornado +tnt naked de cat down-pipe exhaust header, you remove that restriction entirely. The result is a freer-breathing engine that responds more crisply to the throttle, delivers a stronger mid-range pull, and rewards you with a more satisfying exhaust note that actually suits the character of the bike.

Our header is not a cheap import or a generic copy. Every unit leaves our UK workshop in 304 grade stainless steel — the same specification used in marine and aerospace applications. 304 stainless resists the high-cycle heat that exhaust headers endure, it resists corrosion from road salt and British weather, and it maintains a clean, polished appearance far longer than mild steel alternatives coated in paint or ceramic. This is a long-term investment in your motorcycle, not a temporary fix.

Key Features of the Benelli TNT125 TNT135 Tornado +TNT Naked De Cat Down-Pipe Exhaust Header

• 304 Grade Stainless Steel Construction — premium material throughout, from the collector to the outlet flange, ensuring exceptional durability and corrosion resistance in all weather conditions.
• De-Cat Design — the catalytic converter section is completely removed, eliminating back-pressure and allowing exhaust gases to flow freely and efficiently.
• Precision Mandrel-Bent Pipework — smooth, consistent internal diameter through every bend, maintaining flow velocity and preventing the turbulence that crushed bends create.
• Direct OEM Fitment Points — the header is engineered specifically for the Benelli TNT125, TNT135, Tornado, and +TNT Naked models, using the factory mounting positions for a clean, rattle-free installation.
• Compatible with Max Torque Cans Silencers — the outlet is sized and finished to pair perfectly with our own single outlet performance cans, though it will also work with other aftermarket silencers using a standard collector diameter.
• UK Manufactured — made right here in Britain by people who ride motorcycles and understand what performance riders actually need.

Fitment Guide for the Benelli TNT125 TNT135 Tornado +TNT Naked De Cat Down-Pipe Exhaust Header

This header has been designed with a straightforward installation in mind. If you are comfortable with basic mechanical work — removing fairing panels, unbolting exhaust flanges, and handling heat-resistant gaskets — you should be able to complete the swap in under two hours on a warm engine. Here is what to expect during installation.

Begin by allowing the engine to cool fully before you start. Remove any lower fairings or belly panels that restrict access to the existing down-pipe. Loosen and remove the nuts or bolts at the cylinder head exhaust port, taking care not to damage the threads in the alloy head. Support the factory pipe as the last fastener comes free, as it can drop suddenly and strike the frame or paintwork. Once removed, clean the exhaust port face and fit a fresh copper or steel gasket — never reuse the old one, as a proper seal here is critical to performance and safety.

Offer up the new benelli tnt125 tnt135 tornado +tnt naked de cat down-pipe exhaust header to the cylinder head, threading the retaining nuts finger-tight first to ensure everything aligns naturally. Then work through the mid-pipe mounts before torqueing the head nuts to the manufacturer’s specification. Once the header is secure, reattach your silencer — ideally one of our Max Torque Cans performance silencers — and run the engine up to temperature, checking for any leaks at the head flange before fitting the panels back on.

Please note: removing the catalytic converter means this exhaust configuration is intended for track, off-road, or closed-road use in accordance with UK road traffic legislation. It is your responsibility as the owner and rider to ensure your motorcycle complies with any applicable regulations in your region.

Pairing Your Benelli TNT125 TNT135 Tornado +TNT Naked De Cat Down-Pipe Exhaust Header with the Right Silencer

The down-pipe is only half of the equation. To get the very best from your new benelli tnt125 tnt135 tornado +tnt naked de cat down-pipe exhaust header, you want a silencer that complements its free-flowing characteristics rather than introduces a new restriction. Our Max Torque Cans single outlet performance cans are built with the same philosophy — 304 stainless steel, mandrel-bent internals, and a sound that is aggressive without being antisocial. The two components are engineered to work together, and the combination produces noticeably better throttle response and a stronger top-end surge compared to either component used with factory parts.

If you are also exploring de-cat options for other bikes in your garage, you might be interested in our BSA Gold Star de res pipe 304 Stainless Steel, which follows the same manufacturing philosophy with the same premium materials.

Frequently Asked Questions

Will the benelli tnt125 tnt135 tornado +tnt naked de cat down-pipe exhaust header void my warranty?

Fitting aftermarket performance components can affect your manufacturer’s warranty. We recommend checking the terms of your warranty documentation before fitting any modifications. Many riders choose to retain their factory parts and refit them prior to any warranty inspection.

Do I need to remap or retune the fuelling after fitting?

On carburettor-equipped models such as the TNT125, you may benefit from a slight enrichment of the main jet to suit the increased airflow. On fuel-injected variants, a basic ECU reflash or a fuelling module will extract the most performance from the new header, though the bike will run without one. We always recommend a proper tune for the best results.

Is this header a direct replacement with no modifications needed?

Yes. The benelli tnt125 tnt135 tornado +tnt naked de cat down-pipe exhaust header is a direct OEM replacement designed to use all of the factory mounting points on the TNT125, TNT135, Tornado, and +TNT Naked. No cutting, drilling, or welding is required for a standard installation.

What finish does the header have?

The header is supplied in a brushed 304 stainless steel finish. Over time and with use, the pipework will develop a natural heat patina that many riders consider part of the character of a well-used performance exhaust. If you prefer a polished finish, the stainless steel responds well to metal polishing compounds applied by hand or with a polishing wheel.

If you are building a more comprehensive performance setup across multiple bikes, take a look at our Aprilia RS660 De-Cat DownPipes for another example of the quality and precision we bring to every de-cat header we produce at Max Torque Cans.