Varex BMW Performance Exhaust: An Upgrade to Boost Output and Reliability

For over 50 years, BMW’s M-Series has been the automotive industry’s all-conquering standard for high performance engineering. And with no fewer than 11 distinct BMW coupe, sedan and SUV models offered in “M” trim, their factory upgraded engines, suspension and braking systems are the perfect platform for even further aftermarket upgrades.

Exhaust systems are one of the easiest, and most straightforward upgrades a BMW owner can make to an M-Series – and that’s not only because they’re bolt ons. M-Series exhaust systems are known for a selection of durability issues that can cause power to drop off precipitously. High quality aftermarket systems aren’t prone to the same structural issues that series production systems are, and there’s one aftermarket manufacturer whose systems are as durable as they are good at helping M-Series BMWs breathe better.

Varex Catbacks Are Number One For M-Series BMWs

Whether it’s their aggressive throttle response from idle, or their rock-solid stability at high speed, M-Series BMWs are possibly the most thrilling serial-production high performance automobiles available today. And for owners who want to take their performance to the next level, a high flow catback BMW performance exhaust system from Varex is a sure way to boost M-Series output without modifying the Bimmer’s factory tune or engine parameters.

For almost 20 years, Varex catback systems have been the gold standard for high flow aftermarket exhausts for BMW’s M-Series and M Performance lineups. Output gains of 10kW-20kW, and weight reductions of up to 40kg are characteristic of what Varex high performance exhausts for BMW have to offer, especially when it comes to their most dominant M-Series models, including:

• 2012 – 2016 M135i and 2016 – 2019 M140i F20 hatchbacks;
• 2014 – 2016 M235i and 2016 – 2020 M240i F22 coupes;
• 2015 – 2018 N55 F87 M2 coupes;
• 2014 – 2019 F80 M3 sedans; and,
• 2014 – 2019 F82 M4 coupes.

With their mandrel bent 2.50″ and 3.0″ tubes and fully welded flanges, Varex BMW performance exhaust systems are perfect for the M-Series’ fast spooling, mono-scroll turbochargers. These catbacks turn on the power quicker than practically any aftermarket BMW exhaust system available today. That’s because they’re dyno-tuned and balanced to deliver maximum flow in the low RPM range where the Bimmer’s aggressive boost and peak torque reside – and because Varex is number one when it comes to the fundamentals of exhaust design.

Creating Consummate Conditions For Turbo Engines To Thrive

Varex engineers understands that when it comes to BMW performance exhausts, there’s no substitute for the fundamentals – and this is especially true with systems used with forced induction engines. Not only do they produce higher volumes of exhaust gas, they also need to get rid of them faster and more efficiently than their naturally-aspirated counterparts. Rapid spooling powerplants like the Bimmer’s indomitable twin-turbo straight-6 is among them, and only a low restriction BMW performance exhaust system that’s engineered to quickly draw spent gases out will suffice.

Exhaust system fundamentals are at the core of every Varex-engineered BMW aftermarket exhaust, and they’re built to promote the following:

• An increase in exhaust scavenging. Exhaust scavenging utilises the vacuum differential created by exhaust gases traveling from high pressure to low pressure to assist with rapidly drawing successive charges of fuel and fresh air into the engine.
• An increase in exhaust gas velocity. Whether it’s the result of increased scavenging, or the high speed airflow caused by spent gases being drawn through alternating sized exhaust tubes, an increase in exhaust gas velocity offers an immediate improvement in engine combustion.
• A decrease in exhaust backpressure. Backpressure is caused by any measure of resistance that affects airflow inside the exhaust system. Smooth diameter tubing, mandrel bends and TIG-welded joints keep backpressure to a minimum, allowing better flow throughout an engine’s full RPM range.

Ideally, top-engineered turbo exhaust systems are capable of achieving optimal scavenging by keeping exhaust gas velocities high and backpressure low. These are the conditions that Varex BMW aftermarket exhaust systems are designed to encourage, all of which add up to an engine that thrives on noticeably faster throttle responsiveness, and isn’t burdened by unwanted turbo-drag, excess heat buildup or potentially dangerous detonation.

Materials and Configurations That Are M-Series Compatible

Varex prides itself on their extraordinary understanding of exhaust thermodynamics, as well as the importance of fluid and acoustic balance. They’re also aware, however, that the materials and the configurations they use for any high performance exhaust for BMW matters as much as the engineering behind it. The structural difficulties OE M-Series Bimmers are known for, including cracking and rattling, are largely the result of material and fitment stresses. Fortunately, Varex catback BMW aftermarket exhausts aren’t prone to those issues.

304 stainless steel is the material of choice for all Varex BMW M-Series exhausts. Only 304 offers the high tensile strength and corrosion resistance that hot-running turbo Bimmer exhausts need to maintain both their high temperature integrity as well as their show-quality finish, and are used for all M-Series and M Performance catback components, including:

• Single and Dual 2.50″ and 2.75″ inlet to dual 3.0″ tubes;
• Single to 2.50″ slits to single 3.0″ collector tubes; and,
• Dual equal length 2.50″ centre-section tubes.

Varex premium-valved catback mufflers are also crafted from versatile 304 stainless. These mufflers are the perfectly tunable complement to any aftermarket exhaust for BMW M-Series or M Performance model, aren’t prone to the cracking or fracturing that OE mufflers are notorious for, and are manufactured in a range of compatible configurations that include:

• Dual valved mufflers with 3.0″ inlets and outlets;
• Single valved east – west mufflers with 3.0″ inlet and dual 3.0″  inlets; and,
• Dual valved east – west mufflers with 3.0″ inlets and quad 3.0″  outlets.

Varex mufflers give M-Series drivers complete control over their exhaust’s sound as well as their performance. And when capped off with a pair of their twin 4.0″ 304 stainless tips boasting either a polished, matte black or burnt blue finish, they look as good as they sound and perform.

The Final Word

At the end of the day, with their brutal acceleration, virtually perfect weight distribution and knife-edge handling, M-Series BMWs are in a class all their own. As powerful as they are though, they still have plenty of power in reserve that can be uncorked with a bolt-on that’s built to last.

A high flow catback BMW performance exhaust system from Varex has all the qualities an M-Series or M Performance owner needs to simultaneously boost their output and reliability. That makes them an investment in bolt-on performance that pays big dividends.