Better Flow – More Go
Exhaust systems are fitted to remove hot, noxious exhaust gases from your engine, reduce engine noise and reduce exhaust emissions. While the factory-fitted exhaust system on your tow vehicle may perform reasonably well, there are usually significant benefits to be gained by replacing it with an after-market exhaust system.
Most argue that the key to this improvement is to reduce exhaust back pressure, usually achieved by using larger-diameter tubing and free-flow mufflers. However, what’s actually required is to minimize the resistance to gas flow in order to keep the exhaust gas flowing as quickly as possible so that the burnt gases are efficiently extracted from the engine.
This means that the saying ‘bigger is better’ is not always the case. In fact, the optimum diameter of the exhaust tubing varies according to the amount of exhaust gas being produced, which depends upon engine RPM and load. While this means that it’s not possible to design an exhaust system that works perfectly under all engine conditions, it is possible to design a system that performs significantly better than the original equipment.
Beaudesert Exhaust is one aftermarket supplier that really understands exhaust systems and can custom-make a system for just about any internal combustion engine. Beaudesert Exhaust has an edge on most of the com- petition because of its long experience in manufacturing mandrel-bent tubing.
Most exhaust system piping is shaped using hydraulic presses, which has the unfortunate effect of reducing the pipe diameter on all bends, making it harder for the engine to get rid of the exhaust gas.
By comparison, mandrel bending preserves the original pipe diameter throughout the bend and therefore does not have this problem. The way it works is that the pipe is prevented from collapsing on itself while being bent by the mandrel, which is inserted inside the pipe.
Quality mandrel benders are unmatched in being able to produce flawless bends quickly and with minimal distortion of the tube. “When looking at a normal bent piece of tube,” business founder Brian Parker explains, “the wall on the outside of the bend is stretched and thinned while the inside wall is compressed and becomes thicker. Our CNC benders are capable of factoring in the bend elongation and are able to maintain a uniform thickness of the tube throughout the curve. This not only keeps the tube diameter the same along the entire length of pipe, but the wall thickness stays constant too.”
What’s even better about the machines that Beaudesert Exhaust uses is that they are Computer Numerically Controlled (CNC) machines. This means that once set up, the machines will repeat the same bending profile with extreme accuracy, time after time. This means that customers always get an exhaust system that fits without requiring modification.
So far we’ve only discussed the pipes that are used in the exhaust system and how these can be made better than the original. However, there’s more to an exhaust system than just the pipes, and Beaudesert Exhaust can provide all you need, from turbo dump pipe to tailpipe and everything in between. For non-turbo motors, Brian and the team are currently developing high-performance exhaust manifold replacements known as ‘headers’ or ‘extractors’ that should be on the market very soon.
The turbo dump pipe bolts onto the back end of the turbo and connects it to the exhaust system. Unfortunately, many stock dump pipes are too restrictive, which is why Beaudesert Exhaust has developed a lot of its own.
“We did a lot of work on our turbo dump pipes to get the best possible heat-dispersing properties from them,” Brian says. “We tried making them out of stainless, which heats and cools too quickly, as well as several other materials. In the end we settled on mild steel for some and cast iron for others with an optional HPC coating to give the best heat properties at an affordable price.”
Other components like flexi-joints, catalytic converters, resonators and mufflers are purchased from other suppliers to Beaudesert Exhaust’s specifications and designed into an integrated system by Brian and the team.
Unless otherwise specified by the customer, the new system follows the same pipe routing as the stock system and utilizes the original exhaust mounting points. The system comes in a number of sections that are bolted together using CNC laser-cut flanges for accurate alignment and ease of assembly and future disassembly. To ensure accuracy and repeatability during manufacture, all components are assembled on jigs made in-house by the resident toolmaker.
Beaudesert Exhaust was established in 1980 by husband and wife team Brian and Jane Parker. Located in Beaudesert, southeast Queensland, the company specialises in designing and manufacturing 4WD exhaust systems using computerised mandrel- bending technology. Most customers are not rev-heads, but 4WDers and RVers like us who want a reliable, long-lasting exhaust system that will give noticeable power and torque gain with reduced fuel consumption.
As customer John Hetherington commented, “My 3L Patrol used to struggle through the hills closer to the CBD. Now I have gained an extra gear and the pulling power has increased significantly. The turbo comes on at least 300rpm lower and pulls a lot harder. Fuel consumption has improved as well.”
Making the entire system from either aluminised or stainless steel assures long product life. Ordinary black steel rusts from the inside out,
especially on petrol vehicles, and often fails completely before any rust is detected. The aluminised coating
is sufficient for most environments, but stainless steel is recommended for seriously hostile environments.
Good system performance is assured by Beaudesert Exhaust’s continuous improvement program that is based
on feedback from customers. “The only way to find out what people think about your product is to ask them, and so we include a survey form with every system sold,” Brian informs us. “Most of our customers are only too happy to fill out and return these forms, and sometimes we get some good information that leads to improving the product in some way.” Sounds like a good plan to us!
Customers can order complete sys- tems or any part of a system over the phone and quotes can be requested via the website. To reduce shipping times, stock of the most common systems is maintained in the on-site warehouse.
Customers that require something out of the ordinary are invited to give the friendly staff a call to discuss their particular requirements. For example, custom systems can be easily designed to cater for aftermarket gas, water or auxiliary fuel tanks, or side exits for vehicles with large ‘Rock Tamer’ style mudflaps. Customers can also specify the type of silencer (muffler or resonator) to be included.
Many customers organise to have their new exhaust system fitted by the team in Beaudesert, and they have multiple fitting bays dedicated to this purpose. Some of their customers even organise their trips so that they can drop into the factory, just to get theirnew exhaust fitted.
“They come from all over the country too, not just from south-east QLD,” Brian informs us, “just like a bloke from Katherine who rang us up the other day to order his system and book his 4WD in for fitting in a couple of weeks”.
If a trip to Beaudesert is not on the agenda, all Beaudesert Exhaust systems are designed to be ‘bolt on’, so they can be easily installed by your local mechanic or as a DIY job for anyone with reasonable mechanical ability.