Getting more grunt through an aftermarket exhaust system

ByUnsealed 4X4October 19, 2020
Getting more grunt through an aftermarket exhaust system

Mark Allen speaks to Brian Parker, the man behind Beaudesert Exhaust, to find out how a well-designed exhaust system can give your 4X4 a serious performance gain.

Unsealed 4X4: Beaudesert Exhaust started way back in 1982. What attracted you to the aftermarket exhaust system business?

Brian Parker: There was no exhaust shop in the town of Beaudesert, so I decided to leave the meatworks and start up my own shop. I started on my own just doing standard exhausts. Ten-years later, I saw there was a niche in the market for four-wheel drive exhausts and decided to buy my first mandrel tube bending machine to develop these systems. It was from there we just grew and now house eight CNC mandrel tube bending machines.

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Brian’s knowledge of pipework is second to none.

U4X4: As well as exhaust systems, what else does Beaudesert Exhaust manufacture?

BP: We have an extensive skillset. Jobs completed by our team include – but are not limited to – standard exhaust systems, specialised custom exhaust systems, snorkels, side rails, extractors, intercooler piping, headboards, ladder racks, pool rails and heat exchanges.

U4X4: How critical was it to first start using CNC mandrel bending machines instead of the standard bending methods?

BP: Mandrel bending was starting to come in on high-performance exhaust systems for streetcars. The performance gains that were seen between mandrel bending versus the traditional press bending were significant. In 1995 we bought our first CNC mandrel tube bender and started producing exhaust systems for the four-wheel-drive market. You can gain approximately five per cent performance on top of press bent exhaust tube. The popularity grew, and now we have eight CNC mandrel tube bending machines, and we can bend from 1 ¼” to 5″.

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A workshop full of the latest high-tech bending and CNC machines.

U4X4: Do you supply kits for the home DIYer to install themselves?

BP: Yes, all of our systems bolt on and come with full fitting kits and step-by-step instructions on how to install them.

U4X4: With the current trend of 4X4 owners wanting larger-diameter exhausts, is this the best way to achieve more power and torque? Are there downsides of going too large?

BP: The easiest way of gaining better performance out of the factory car is to fit a larger-diameter exhaust to the vehicle. But be careful; going too large can have the opposite effect. We have found in our research, development and testing that going too large can lose low-down torque, which is when you need the power for towing caravans and heavy equipment.

U4X4: While all vehicles are different, is there a rough rule of thumb as to how much extra power and torque can be achieved from a well-built exhaust system, and would it see improved fuel consumption?

BP: Turbo-diesel, (with) pre-DPF (diesel particulate filter) cars, you will gain anywhere from 10-12 per cent in performance and 8-10 per cent in fuel economy. With DPF fitted vehicles, you will see 4-7 per cent in performance.

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Plenty of exhaust systems in stock, ready to be dispatched.

U4X4: Let’s talk materials. Explain the difference between 441, 409, 304 and 316 stainless steel, as well as aluminised steel and mild steel, and why or why you wouldn’t use each material in an exhaust system.

BP: Mild steels iron content is very high, so it will rust quickly if not treated.

Aluminised steel is a mild steel with a hot-dipped aluminium silicon coating. The aluminium coating of the tube protects the outside layers of the tube, so it is excellent for an exhaust system.

Factory exhausts are made up of 409-grade stainless steel. This tube is only 10-11 per cent chromium. This can be welded with mild steel wire and is suitable for heat expansion.

304-grade stainless steel is the highest quality exhaust grade material available. With an 18-20 per cent chrome content, this material will last the life of the car.

316-grade stainless steel has the most chromium content and is therefore known as marine grade stainless. It can be used in coastal areas if people prefer as it is less prone to deterioration due to the elements.

441-grade stainless steel holds the same chrome content (18-20 per cent) allowing it to be polished up, as can be seen on Pat Callinan’s Ultimate Amarok.

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Brian’s first mandrel bending machine.

U4X4: Do you sponsor any form of sport or charity events?

BP: We sponsor regular golf days at our local Beaudesert Golf Club. At Christmas time we like to sponsor the lighting up of the town.

U4X4: Does your family get involved in the running or operating of the business?

BP: We are a family-owned and run business. My wife came on board in the year 2000. From there, our two sons and daughter-in-law became a part of the team.

U4X4: What are your favourite off-road destinations, and what vehicle do you own?

BP: I own a Toyota V8 70 Series LandCruiser and Fraser Island would have to be our all-time favourite. We try to get up there multiple times a year.

Fraser Island

Brain’s getaway machine at his favourite haunt – on Fraser Island.