Get More From Your Commodore With the Right Exhaust

At the zenith of the Australian car industry, two carmakers reigned supreme – Holden and Ford. And the battle between the Commodore and Falcon was unlike any other rivalry in Australian history. Both models at one time were the country’s best-selling, and both took podiums in countless races to mark their superiority. Those days may have gone, but there are still worthy reminders on the streets. 

Holden remained faithful to its naturally aspirated V6 and V8 engines (with few notable turbocharged exceptions) and the cars were easily tuneable to belt out even more power. Simple and relatively inexpensive additions, such as quality aftermarket Commodore exhausts, are the first parts when considering tuning or modifying any engine for more power. A well-appointed exhaust, built to or exceeding OE-spec standards, opens up the engine, lets it breathe, and reduces internal stresses. 

It also lasts longer in daily runs and when you’re harder on the acceleration pedal. Paired with an equally capable intake to push more air in for combustion and a high-flow carburettor or fuel tune, the parts can significantly increase available power and torque even at lower RPMs, and give your Commodore more push when nearing redlines. The deep, throaty sound thrashing from the tips is just a bonus. 

Why Have an Aftermarket Exhaust?

Regardless if you’re sitting in the 5.0-litre V8 in the VN, VP, VR or VS cars, or the bigger 5.7. 6 and 6.2-litre Commodores and HSVs that followed, an aftermarket exhaust, complete with wider tubing (up an inch in diameter over stock) and a suite of extractors and high-flow converters, lifts mediocre power figures by up to ten per cent of the claimed factory figures of 168kW for the 5-litre mill and 230kW for the bigger displacement engines. The same applies to the 3. 3.6 and 3.8-litre V6s. The results are most evident when on the pedal: 

• Improved airflow and reduced backpressure – wider tubing frees up space for spent combustion gases. The faster they exit the car, the more power the engine can produce with quicker combustion cycles. A nice by-product is that gases don’t linger around or make their way back to the cylinders in what is known as backpressure. This can cause power loss and negatively impact parts like exhaust valves and cams. 
• Faster acceleration and better throttle response – Commodore exhausts help the cars build power linearly, translating to faster take-off from a standstill, better in-gear acceleration, reduced overtaking times and more feel when on the acceleration pedal. 
• Improved longevity – stock exhausts use mild steel and crushing bending to produce parts that are adequate at most. The parts are subject to rupturing, staining and corrosion, even in shorter daily driving bouts. When choosing a Commodore performance exhaust, you get mandrel-bent stainless steel that is not only built to a higher standard, but is also stronger and can resist higher temperatures when pushing the engine, and stay intact when encountering road debris and bumps or surrounded by water and mud. 
• Deeper, louder sound – part of the reason to go with a performance Commodore exhaust is that it tells you everything the engine is up to with a nice, deep and throaty sound bellowing out from the tips. This can also be tuned when combining different parts along the exhaust tubing, such as muffler and resonator combos, or when going with valved systems that get louder the faster you go. 
• Reduced weight – Commodores are big and heavy, but any saved weight is vital if you’re also serious about racing. A full system from headers to tips can reduce overall weight over stock by some 20 kilos. 
• Different options, parts and configurations – the pricing of performance car parts can get ridiculous, but exhaust components buck that trend by being reasonably priced, unless you choose exotic materials or one-off builds. Holden owners can choose between axle-back, cat-back and header/turbo-back systems, each in their price range and each with different benefits. For looks choose an axle-back system, for better sound a cat-back exhaust will suffice, and for the complete package a header or turbo back. Moreover, different parts like extractors, straight pipes, high-flow converters and more can be mixed and matched to get the desired results.   

Choosing the Right System for Your Commodore

Exhaust systems for the Commodore will differ in width, layout, the included parts, materials and price. There are also different bands to choose from. The 2.5″ and 3.0″ are the most common widths. The first is intended for the street and everyday driving, while wider variants are better at relieving excess backpressure and can be mated to high-flow cold intakes for even better results. 

Layouts also need to fit within the stock recesses for a cleaner fit, reducing the need for any modifications or additional mounting hardware. As mentioned, full Commodore exhausts produce more power, but they will also cost more. Prices are also determined by the addition of other performance necessities like extractors or straight-tube catalytic converters and whether you want resonators to tame the sound. 

Materials also matter. Stainless steel is the entry point to performance systems, but tubing, tips and parts can also be made of carbon fibre, Inconel and other high-end materials. Lastly, brands market their own proprietary tech or production methods, promising better results or more longevity. What you choose will be based on your expectations and whether these fit within your budget.