There’s hardly a high performance engine builder anywhere who hasn’t wrestled at least once with the question of how to select the perfect tubing length and diameter for a custom exhaust build. Even in Australia where classic high performance juggernauts like Holden HSVs and Ford Barras have benefitted from massive factory research into optimum exhaust flow dynamics, custom builders are typically left to calculate their own best gas pressures and flow rates.
Fortunately, however, today’s custom builders have access to the same high quality, easily fabricated exhaust tubing as the factories. It’s the assurance capable builders need to craft the most precise, best fitting, and ultimately most efficient custom exhaust systems possible.
Getting Big Benefits From Universal Exhaust Tubing
Let’s be honest: while there are thousands of high performance and special duty exhaust systems on the market, the fact is they don’t all fit as intended. Even minor differences in floorpan designs and hanger locations can affect how well a system fits. That’s why when it comes to custom engine design, experienced builders insist on starting with high quality universal exhaust tube segments and fittings that they can assemble to satisfy their specific requirements.
Regardless of the size of an engine or how much power it’s producing, the objective behind all successful exhaust designs are the same: to draw-out spent exhaust gases as quickly and as efficiently as possible. Universal exhaust tubing gives builders the latitude to fabricate exhaust systems that can be tuned to meet those objectives, and offer a core of pure builder benefits that include:
- Complete freedom to customise. From mild to wild, universal tubing segments give engine builders the freedom to create bespoke exhaust systems that offer maximum scavenging and exhaust gas velocity while also keeping backpressure to an absolute minimum.
- Unmatched compatibility and compliance. Not only do universal exhaust tubes allow designers to build systems that are compatible with any powertrain and suspension, they also make it easier to ensure full compliance with any and all relevant ADR noise and emissions requirements.
- Unequalled availability and affordability. Tuners are able to purchase virtually any length or diameter of universal tubing direct from any trusted local or online dealer. The cost to purchase and assemble universal tubing will also be noticeably less than even the most affordable aftermarket system, giving them a clear affordability advantage.
And while engine builders certainly appreciate the advantages universal exhaust tubing offers for one-of-a-kind fabrication jobs, it’s no-less advantageous for a full range of OE exhaust repair activities. Suitably-sized lengths of universal tubing are perfect for cutting out and replacing damaged or rust exhaust sections, and can be permanently secured by welding or any high quality, ceramic-based exhaust sealant.
Solid Universal Tube Attributes For Any Exhaust Application
Because universal exhaust tubes aren’t manufactured to fit any specific vehicle make or model, the sheer range of tube lengths and bore options that are available to engine builders and exhaust fabricators is staggering. And as tubes can be bent, arranged and assembled to accommodate virtually any engine or body configuration, builders can tailor each system to their precise requirements.
Any well-stocked exhaust system retailer is likely to carry a full selection of tube segment inventory, which would include:
- Aluminised steel tubing. Durable aluminised steel tubing is the choice for most standard and off-road exhaust systems. It’s ordinarily available in 1.6mm and 2.0mm wall thicknesses, and is sold in both mandrel and non-mandrel bendable variations for maximum utilisation.
- Stainless steel tubing. Corrosion-resistant 316/304 and 409 stainless steel tubing is lighter than aluminised steel. Typically, it’s manufactured in 1.5mm and 2.0mm wall thicknesses, and is preferred for high performance exhausts systems where heat and corrosion are problematic.
- Mild/black steel tubing. Unlike aluminised and stainless steels that are treated for corrosion- and chemical-resistance, uncoated black steel tubing forms its own protective oxidation layer. It’s manufactured in 1.5mm and 2.0mm wall thicknesses, and offers excellent formability, weldability and durability at a reasonable price.
- Stainless steel perforated tubing. Perforated 409 stainless steel exhaust tubes can be used as either heat shielding for the outside of an exhaust system, or as noise suppression from the inside. A standard wall thickness of 1.5mm makes it ideal for both functions, and can easily be welded into position in either capacity.
- Special tubing sections. Whereas ordinary lengths of straight tubing are designed to be cut or bent to fit any contour, special tubing sections like pre-formed stainless steel universal X-pipes and shapable bellows-style flex pipes are designed to make complex exhaust flow configurations simpler to install and easier to repair.
The convenience and versatility of universal exhaust tubing make it possible for builders and fabricators to design and mount a fully customised exhaust system on any hot rod, race car, or street-legal performer with full confidence in its ability to move spent gases away from the engine. And make no mistake: because the cost of allowing spent gases to linger in the system can effectively destroy engine performance, the benefits of using a custom tuned and tested system to keep them moving are too big to ignore.
Understanding the Basics of Exhaust System Design
While it’s no secret that exhaust tuning is the quickest and most efficient way to increase engine output, the fact is, even the most capable engine builders can get lost in the aesthetics of exhaust design. That’s because it’s easy to fall into the trap of relying on oversized tubes to compensate for proper flow dynamics. And this is especially true when universal exhaust tubing is used, where opting for oversized pipes can actually reduce exhaust gas velocity, resulting in an instantly noticeable drop in engine output and fuel economy.
When engineered around the basics of superior air management – not oversized tubes – an exhaust system built with universal tube segments will immediately see the following benefits:
- An increase in exhaust flow volume. A well designed exhaust system excels at drawing large volumes of spent gases from high pressure to low pressure; and systems made from universal tubing can be dyno-tuned to remove unwanted gases faster than any other type of system.
- An increase in exhaust gas velocity. Thanks to their ability to rapidly remove spent exhaust gases from the system, custom exhausts excel at drawing fresh air/fuel charges into the engine.
- A reduction in exhaust system backpressure. Backpressure is regarded as any type of inline resistance that restricts gas movement. As universal exhaust tubing is designed for mandrel bending, universal systems, complete with TIG-welded joints and flanges, are capable of eliminating virtually all manners of inside diameter resistance.
From their lighter weight and heat resistant coatings, to the ease with which of varying diameter segments can be combined to increase internal pressure, universal tubing helps engine builders stick to the basics of exhaust design. And with the independence to chart their own custom tube fitment and underside routing, they’re also able to rein in excess exhaust noise and heat that can find the way into the passenger compartment.
The Final Word
At the end of the day, while factory-furnished exhaust systems typically provide the best balance of cost, reliability and regulatory compliance, they’re rarely ever engineered to support an engine’s best performance. And as engine builders and tuners are often capable of increasing the output from many of today’s engines exponentially, the ability to craft equally capable exhaust systems is a priority.
High quality universal exhaust tube segments and fittings are the correct answer for builder and tuner exhaust system concerns. They’re the perfectly reliable and cost effective solution for getting every ounce of power an engine can produce to the ground.