Mark III/L322 Rear Exhaust Upgrades


Rear exhaust upgrade
Introduction
Michael's Solution


Photo at right: Michael's much smaller rear muffler in place on his TD6

Introduction
On most 4x4s, including the Mk III's predecessor and the Range Rover Sport Supercharged, the exhaust tailpipes are the most vulnerable items likely to be destroyed in real-life four wheeling. The Range Rover III designers did a much better job than most in arranging the rear exhaust tailpipes so they do not protrude at all from the underbelly. However, the rear muffler is especially large and bulbous, and in real life four wheeling the rear overhang is the most common ground contact area on almost any vehicle. For those of us who use our Range Rovers for their intended purpose, the huge rear muffler can be the limiting factor in getting through certain obstacles like washouts and rocks. Michael Quinn encountered such a problem on his Mk III Range Rover, and was kind enough to share his solution with other owners.

Meanwhile, aftermarket exhaust systems for the Mk III have emerged. The Borla system is mainly intended to increae power output by freeing up exhaust flow, but a side effect is that the much smaller mufflers used provide improved ground clearance for four wheeling. These systems are also described bekow.

Smaller rear muffler


Michael's Solution
Rear muffler with good clearanceMichael reports "Just over a month ago I managed to tear off the rear muffler on my 2005 TD6 whilst out on some rocky trails. As you will see in the pictures a much smaller muffler is used which offers significant additional clearance to the rear of the vehicle".

Michael undertook a process of trial and error to design a replacement muffler that would not drag on the ground. It took three successive attempts to get the baffle combination right as the first two mufflers where either too big or restricted engine performance. In fact, one led to a noticeable increase in fuel consumption as well as reduced performance.

Regarding his final design, Michael reports: "The one illustrated here (above and at right) is very compact and is tucked up high against the rear cargo floor where there is no likely chance of getting hung up when off road. The engine breathes much more easily with even more response when accelerating and better fuel economy. There is slightly more noise from the smaller baffle but is not intrusive."
 
Michael thought his solution might be of interest to other owners if they, like us, enjoy the level of serious off roading of which the Range Rover is capable.


Stock RR V8 ExhaustNote on Petrol (Gasoline) Powered Range Rovers
It should be noted that the solution illustrated here is for a TD6 Range Rover which has only one exhaust pipe extending back to the rear of the vehicle. The petrol/gasoline-powered V8 models have two pipes (one from each cylinder bank) that reach ther rear muffler assembly (note raised section of suspension member in photo above that is wide enough for two pipes to pass under it).

Accordingly, for the V8 models a slighly different approach will be needed, probaly utilizing two small mufflers in place of the stock huge double mufffler assembly. If anyone has tried this, please email me so we can share it with other owners.

Photo: Stock V8 rear muffler showing its limiting effect on ground clearance compared with Michael's unit above.


Borla Exhaust for RR III
Borla Exhaust for RR IIIOne option for the V8 model is the new Borla exhaust that has been developed for it. Their replacements  for the stock rear muffler assembly (see bottom portion of picture at right) are much smaller than the original, and therefore less likely to get hung up on rough terrain.

The Borla system uses aircraft-quality T-304 stainless steel construction (lighter and stronger than conventional steel), and is fully welded without crimping for umimpeded flow-through. Slip-fit connectors provide an easy, secure fit. Maintenance-free sound absorbing materials maintain low dB’s, protects against burnout and reduce shell temperature.

These exhausts not only improve rear clearance but actually improve engine performance. They have a 1 million mile guarantee, and are legal in all 50 states. Cost is about $850.

Photo courtesy of Atlantic British


 



 

 

 

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Page revised February 1, 2012