THE TONNER has been registered and on the road for just on five months, clocking up more than 5000km. While thatís not an overly time behind the wheel, one particular part of the build makes itself known every single time I drive it on- or off-road: the noise.
Donít get me wrong, I love a strong, deep-noted V8 engine and exhaust note, but my Tonner develops an unbearably hostile buffeting at 100km/h in sixth (top) gear. Itís like that annoying, earbelting drum you get when the rear windows of a four-door vehicle are wound down, but ten times worse. The noise was so bad on its first big drive to The Deni Ute Muster that I ended up rolling tissue paper and stuffing it deep into my ears to drown out the sound. I could prevent the noise by changing the airflow via either dropping down to fifth gear or moderating the vehicle speed, but who wants to do that all the time?
Given the 6.2-litre LS3 pours gasses into the 4-2-1 extractors, dual cats and then into a single 3.5-inch exhaust with single, long muffler, the problem seems to be the overly large diameter exhaust combined with the inability to fit a second muffler or resonator at the rear, given the lack of underbody space.
Iíve got a smaller diameter muffler lined up and will make a reducer from 3.5- to 3.0-inch to weld it into position. Failing that, perhaps Iíll change the complete system to three inches, but it is a little trial-and-error given the lengths and route are vastly different to the Maloo R8 the engine was plucked from.Plus, no two exhaust mobs have offered the same advice.
On a more positive note: right from the get-go I wanted serious, aggressive rubber on my Tonner 4x4. The Coopers STT Pros are quieter than expected and I canít get over how discreet they are for a muddie. They arenít smooth on-road, but, for a dedicated mud tyre, they sure beat a fistful of other muddies Iíve had the misfortune of listening to over the years.
The STT Pros are nothing short of phenomenal off-road. They grip like thereís no tomorrow and return excellent stopping and corning grip on all surfaces Ė even bitumen. The rubber capably controls the Tonnerís excessive power and agility, in addition to the Superior Engineering Superflex sway bars. These bars provide apt on-road body control as well as excellent off-road flex, without having to fiddle with sway bar disconnects.
Peddling the Tonner on- and off-road is a blast, but that high-speed buffeting really needs to go so that I can enjoy the exhaust tune.