|Optimum gas flow and minimal exhaust back pressure is essential for high power. The APS high output 304 grade stainless steel exhaust system really performs.
Careful attention to tube diameter, smooth radius mandrel bends and muffler design is essential for high performance. With 20 years of experience in exhaust system design, APS has produced the ultimate XR6 Turbo exhaust system.
A huge 3.5 inch tube scavenges hot exhaust gasses from the turbocharger, through the innovative APS catalytic convertor where it continues as a single 3.5 inch tube to the mid mount muffler. Internally the muffler splits the exhaust gas flow into two smooth bore 2.5 inch pipes which are routed over the rear axle assembly and into the APS High Output twin 2.5 inch resonator.
|A single 3" turbo to tailpipe exhaust system was eliminated early during the development process due to a number of reasons. Firstly, a 3" exhaust with a 3" catalytic convertor is not sufficiently large enough in volume to deliver low exhaust back pressure at turbo pressures of 9 psi and above.
In addition, the APS twin 2.5" rear section provides greater clearance and reduces radiant heat loads to the plastic fuel tank. An added benefit of utilizing twin 2.5" rear section is the elimination of the highway drone issues faced with a single 3" exhaust.
APS has produced a perfectly balanced total exhaust solution - the cross sectional area of the 3.5" front exhaust at 9.61 in2 (62.1 cm2) grows to 9.81 in2 (63.3 cm2) in the twin 2.5" rear section. Compared to the cross sectional area of the standard exhaust at 7.9 in2 (51.3 cm2) and a tiny 7.1 in2 (45.6 cm2) of a 3" exhaust, the APS system delivers a huge reduction in back pressure at high power levels.
Ute exhaust system shown left and sedan exhaust system shown right
The end result is an exhaust system designed to support high outright power levels of over 500 horsepower, with strong mid range torque. All this with improved turbo response (less lag) and maximum durability.
APS has also gone to great lengths to custom design the highest quality catalytic converter - fully imported from Germany. Whilst the standard catalytic convertor is less restrictive than most after market performance cats available in Australia, the APS cat is streets ahead again. With true 3.5 inch inlet/outlet connections, it features a high flowing stainless steel monolith packed in stainless steel mesh. No other aftermarket converter (and few O.E.M. pieces) are constructed to such a high specification level.
Careful attention has been paid to exhaust noise and note. A strong but subdued exhaust note, comfortable highway cruise and well matched to the dynamics of the Falcon XR6 Turbo.
The APS High Output Exhaust system is engineered as a complete system including every nut, bolt and gasket required for installation.
As always APS has gone well beyond common aftermarket engineering levels to create the ultimate XR6 Turbo exhaust system - regardless of cost. Why settle for anything but the best!
Ute exhaust system shown above. Note: Ute exhaust system is specifically designed for perfect fitment into the Ute version of the XR6 Turbo and differs slightly from Sedan exhaust system.
|High Power, low back pressure and precisely constructed. The APS trademark.
A true free flowing exhaust system that delivers significantly reduced back pressure results in increased turbocharger pressure on the XR6 Turbo. When sufficiently high turbo pressure occurs, the standard engine management system may not operate correctly (commonly referred to as 'Fuel Cut').
Needless to say, an exhaust system that is compatible with the standard engine management system is too restrictive at high power levels.
Fitment of the APS exhaust system as a stand alone product requires the installation of a Unichip computer as well as high flow fuel injectors - in order to not only overcome the fuel cut which occurs at higher boost levels but to also unleash the full power delivered by the exhaust system (through optimization of the ignition timing, air/fuel ratio and boost pressure across the entire RPM range - in high power applications 330+ kW).
Consequently, in an effort to provide our customers with the optimum performance solution in a cost effective manner, APS provides the High Output exhaust as a part of the total PHASE II High Output System.
Simply select the phase of engineered adrenalin you require and take advantage of APS' 23 years of experience in forced induction systems design engineering and production.
APS XR6 T Exhaust System - Design Criteria
High power, low noise, EPA legal.
- Must produce high power, have extremely low back pressure, comply to ADR 79/00 engine emission test and not exceed the 90 dB EPA noise test, have acceptable NVH at cruise speeds between 40 to 160 KPH.
- A 3 ½ “ Euro 3 spec high performance Cat Converter is utilised to ensure low back pressure.
- At maximum rated power 330 kW the back pressure is less than 2 PSI, compared to the stock Falcon converter which has 7 PSI back pressure at 240 kW
Intermediate Pipe 3.5”
- The intermediate pipe is manufactured in 304 grade stainless steel. Tube size is 3.5”, exhaust flanges 304 stainless steel.
- Objective high gas flow, reduced back pressure and long service life.
- Single 3.5” entry, spills into twin 2.5” passages. Objective: high gas flow, low back pressure, low exhaust noise.
- Constructed in 304 stainless steel, internal and external, twin 2 ½ outlet tubes, 304 stainless exhaust flange.
Tail Pipe Rear Muffler
- Twin 2 ½ pipes into rear twin 2.5” muffler with twin 2.5” stainless steel tips.
- Complete assembly including exhaust flanges 304 stainless steel. Tig welded.
- Objective: high gas flow, low exhaust back pressure, high power, low noise EPA legal.
APS Exhaust System Testing
- Easily passes EPA stationary noise test. Actual result 87 dB at 3900 RPM EPA specified test.
- Emission test as part of the Phase II system power continued compliance to ADR 79/00.
- Produces 330 kW (450 HP) as part of the Phase II System with less than 2 PSI total exhaust back pressure.
- Extremely low NVH at cruise speeds of 40 to 160 KPH.
Building and testing a number of different combinations with 3” Cat Converters and single 3” exhaust systems on the XR6 T, proved that this approach is technically flawed, produces high noise and virtually no additional power over the stock XR6 T exhaust systems.
The APS engineered approach for an improved XR6 T exhaust system is a winner in every aspect, and ultimately provides high power with street legality.
Details to look out for when selecting an exhaust system
Unlike other systems that are pieced together using small sections of standard bends and then welded, each section of the APS High Output Exhaust System is formed from a length of continuous tube stock. This ensures the smoothest possible internal surface area for maximum gas flow and longest possible service life of the exhaust components. The picture below shows a typical exhaust that has been pieced together.
In addition, the exhaust above is manufactured from low cost steel. The APS exhaust on the other hand is created using 304 Grade Stainless Steel. 304 Grade has a high nickel content and whilst it is a difficult material to work with from a manufacturing point of view, it is stronger, tougher, more robust and extremely stable at high temperatures found in modern high performance turbocharged cars.
Unlike press bent exhausts, each bend in the APS High Output Exhaust System is precision formed using smooth radius bends that maintain a constant internal section diameter. When forming the exhaust tube, smooth radius mandrel bends are vital for the highest performance and lowest possible restriction. The picture below shows a typical exhaust that has been formed with press bends instead of mandrel bends - with the crimping down of internal section diameter clearly evident.
||Hardware such as flanges are an afterthought from many exhaust manufacturers. In the eyes of APS, the humble flange is a key component that not only joins two tube sections together, but also forms an integral part of the exhaust system as a whole. Precision cut from thick 304 Grade Stainless Steel plate stock, all APS flanges are strong, highly stable at high temperatures and deliver a positive leak-free join for life.
Finally, it is essential that the fabrication of an exhaust system is performed in precise jigs that ensure that the final product is dimensionally correct in 3 dimensions. An ill fitting exhaust places undue stress on exhaust hangers and mounts and can even lead to turbocharger failure through high stress and heat cycling. All APS exhausts are manufactured using sturdy jigs that take into account the expansion and contraction of the exhaust tube as heat is applied during the TIG welding process. All ancillary components such as flanges, brackets and ports are orientated precisely relative to the exhaust tube and the whole assembly secured together tightly during the welding process in jigs such as that shown below.
A precisely manufactured exhaust that is dimensionally correct for the application is vital for long service life.