RML SHORT WHEELBASE AND THE ART OF CHASSIS TUNING
RML ’ s new Short Wheelbase , which is set to launch this October , may appear to have been plucked from the glory days of the classic GT road-racer , but its chassis – much like its interior – has been carefully honed to offer drivers all the sophistication of a modern performance car , but with a more organic and engaging character .
And given RML ’ s extensive knowledge and experience developing performance car chassis as part of the ‘ white label ’ work they do for a variety of OEMs , it ’ s perhaps no great surprise that future Short Wheelbase owners can look forward to a driving experience which rewards and reassures in equal measure .
Nic Rutherford , Project Lead Engineer for the Short Wheelbase , explained his approach to the challenge : “ We ’ re using the platform and chassis from the Ferrari 550 Maranello , which from the start struck the right balance with a broad level of dynamic excellence , but not so highly-strung to be out of kilter with the Short Wheelbase ’ s character . We then needed to adapt the chassis to reflect the significant changes made in the car ’ s design .”
While the Short Wheelbase retains the 550 ’ s wheelbase dimension and suspension pick-up points , its weight , aerodynamics and overall balance are significantly different . As a result , Nic ’ s team swapped the 550 ’ s active Bilstein dampers for bespoke passive Ohlins units tuned to suit the new car ’ s dynamic brief . Springs rates and anti-roll bar ( ARB ) thicknesses were also developed specifically for the lowerweight Short Wheelbase , along with a reduction in ride height for improved control .
The Short Wheelbase ’ s aerodynamics , being different to those of the 550 , also had a bearing on the car ’ s dynamics . CFD ( Computational Fluid Dynamics ) testing allowed the team to predict lift characteristics at high speed , introducing another element of tuning into the mix .
Wheel design was critical to the overall appearance of the Short Wheelbase , too , with its 18-inch alloy rims designed in-house , and its Pirelli P-Zero Rosso tyres selected for their suitability with the new car ’ s chassis set-up . “ We had the option of going with a bespoke tyre ,” explained Nic , “ but we needed to future-proof maintenance of the car for owners in different markets , so having the reassurance that the Pirelli tyre will be in production for the foreseeable future was crucial .”
Finally , chassis stiffness – which has an important bearing on any car ’ s handling and composure – is likely to be improved for the Short Wheelbase . While the 550 M ’ s steel backbone chassis carries over , its largely aluminium body is replaced by a composite structure , with all the attendant benefits in rigidity .
RML is now in the final stages of bringing the Short Wheelbase to market , with ‘ Car Zero ’ ready in October ready for press evaluation , ahead of first customer cars being delivered in Q1 , 2022 .
Nic ’ s team also discovered some happy consequences of reducing the 550 body ’ s front overhang : “ While it hasn ’ t affected the overall front to rear weight distribution versus the 550 , it has moved more of the car ’ s weight towards the centre of gravity , which obviously has benefits in terms of driveability . We also relocated the battery from the engine bay to the boot , which improved the balance still further .”
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