There is an old adage in the car world that to go fast, you need to be able to stop. For Adrian Newey, his laser focus has been even more specific. In creating the Valkyrie, he wanted to engineer the most extreme car ever to wear number plates. Newey’s view of fast specifically refers to a car’s ability to accelerate, brake and corner. Newey thinks in lap times rather than top speed. Frankly, top speed is merely a by-product of the design but never a target.
Therefore, in keeping with this theme, the Aston Martin Valkyrie will come equipped with the most extraordinary braking system ever specified for a road legal car. The brakes naturally need to be commensurate with staggering performance of the Valkyrie. On the track it must be capable of feats of deceleration comparable to that of a Le Mans prototype racer. Naturally track performance is hugely important but it still must be able to operate effectively on the road in all conditions and climates.
This might sound simple but when the braking performance is being raised to such an extreme level, the Valkyrie’s system needs to provide race car performance without the luxury of being stripped down or replaced after each weekend on track. It will also be subjected to road salt, jet washer spray and other environmental factors that the designers need to take into account.
Therefore, braking development was carried out with Alcon who are hugely respected in the race world. There was already a relationship as they supply braking components to Aston Martin Red Bull Racing for its Formula 1 cars and to Aston Martin Racing for its Vantage GT3 racing car. Capable of designing, engineering, testing and manufacturing entire braking systems on site, Alcon have carved an enviable reputation as a supplier of world class braking products and are used by race teams around the globe.
The process of developing the braking system has been in works since 2016 with Alcon receiving a detailed set of specifications and attributes required by Aston Martin and Red Bull Advanced Technologies for Valkyrie. The very nature of the specification and performance demands meant that these brakes would be completely unique to Valkyrie. There was absolutely nothing in existence that was suitable for the job.
The process for developing the brakes begins with a sophisticated CFD (Computational Fluid Dynamics) analysis that is used to create the braking system in a digital format, just like F1 development.They are able to test every aspect of braking performance and can hone and perfect the design long before even prototype parts are built. The next stage is that the components are made and the entire braking system put into one of Alcon’s two full scale dynamometers.This allows Alcon to simulate a full lap of a number of the most significant race tracks around the world to see how they system stands up to full and repeated load. Once testing simulations are complete, the brakes are fitted to Valkyrie development cars to be tested to limits far beyond those it is anticipated even the most committed customers will reach. In total, over 210 brand new part numbers were created for the brakes and pedal box which is also an Alcon design.
To put in perspective some of the requirements required by Aston Martin, it was calculated that the deceleration of the Valkyrie would be in excess of 3g at full braking force. To put that in perspective, a standard family hatchback will typically achieve around 0.9g during an emergency stop on a well surfaced dry road.
To use the Valkyrie brakes is very different to a road car and far more like a race car.They are not equipped with servo assistance, both to minimise weight and maximise pedal feel. This means that to achieve maximum deceleration, a pedal pressure of 120bar is required (a standard road car will usually trigger the ABS at about 40bar).Amazingly, full pressure at the pedal translates to 4 tonnes of pressure at the brake calipers.
While the Valkyrie has some of the largest carbon ceramic discs ever fitted to a road car (420 x36mm (front) and 385 x 36mm (rear), it is not simply a question of fitting the largest possible within the Valkyrie’s wheels. The disc material is crucial as are the size, shape and chemistry of the pads that clamp it. The calipers are machined from the highest grade aerospace-standard aluminium, each one starting as a 38kg billet, reduced to 4.7kg for the finished caliper.This is very different to a typical supercar two piece cast items. The billets that start the process are so large and of such quality that they are unavailable on the open market.This meant that Alcon had to commission them directly from the mill where they are produced. Machining a single caliper takes over 15 hours on a state of the art five axis CNC machine bought specifically by Alcon for the Valkyrie project.
To meet these targets the brakes come with a cooling pattern within the disc that has never been done before.With the enormous forces that will potentially be put through the brakes, keeping temps down was hugely important.Therefore, Alcon have designed up to three times more ventilation holes than you’d find in a more conventional carbon ceramic disc brake. This has required a whole new development process to determine how these discs can be manufactured and then validated.
So we find ourselves with the most advanced and strongest brakes ever fitted to a road car.They are required to stop a mass that weighs less than a typical, small family hatchback.Nevertheless, the ability to reign in the savage power of the 6.5ltr V12 is incredibly important as is the part that braking plays in the Valkyrie’s ability get round a race track like no other road legal car.