Quote:
Thank you for the opportunity to comment on the proposed revisions to VSB14. My comments relate to the LS section on Suspension and Tyres.
LS79
Pg7 Re Installation of variable air suspension systems may preclude the use of pneumatic helper springs fitted to the insides of coil springs and air adjustable shock absorbers if fitted with an in-cab settings adjustment. This will also preclude the aftermarket installation of air springs to 4WD’s etc which include stranded and off-road modes such as those currently provided as OE by manufacturers such as Land Rover
Pg9 Re Suspension travel is a positive move to accommodate the fitting of stiffer springs which are typically used in touring, commercial and towing vehicles which are modified to carry additional weight.
Pg15 Re ESP is logical. If the VSB14 LS does not provide enough scope for consideration of modifications to ESP equipped vehicles, perhaps an engineering signatory will be able to approve or reject any modifications based on individual studies especially as there is an increasing incidence of fitment.
Pg19 Re Max tyre size - tyres must not be larger in diameter than 50mm than the largest fitted by the manufacturer. This is later reinforced in the 50-150mm High-lifted section Pg71 where the max lift which can be provided by an increase in tyre size is 25mm (ie no tyres more than 50mm larger than OE). Should be assessed individually by an engineering signatory as vehicles will vary on their tyre size suitability and nonOE products which are able to increase the capacity of related components. The ability to design vehicle modifications that allow greater tyre sizes within other related guidelines will assist in providing the attainment of 4WD modification goals of increased ground clearance and traction with sympathy to the DOTARS goals of vehicular stability, performance and community perceptions.
Pg69+ Re High lift section, there is control now on the composition of lifts up to 150mm. This includes a 50mmOD increase limit for tyres on pg69, Suspension to be lifted no more than 75mm on Pg71, body lifts no more than 50mm on Pg71. If you lift beyond 50mm then you must undertake a lane change test Pg72 which will determine your max ride height up to a max of 150mm over standard. This section is blanket rather than vehicle specific and perhaps the lift composition is better determined on an individual basis by the engineering signatory. Some suspension designs are more than capable of accommodating suspension lifts beyond 50mm and 75mm while performing to acceptable standards. Likewise the accommodation of various tyre sizes can be constrained by bodywork and so the lift composition between tyre size increases, suspension alterations and body lifting may vary with each vehicle. Some vehicles are also not reasonably capable of achieving all of these lifting processes, but are able to otherwise be modified within these guidelines to run at 150mm lift with acceptable stability and will benefit from a relaxation of this lift composition stipulation. Such vehicles may include those fitted with SRS and those with bodies constructed onto a chassis directly or with unitary construction.
