Exhaust pipes remain one of the last bastions of hand fabricated metallic parts on an F1 (along with radiators). While we can all marvel at the metal shaping and immaculate welding, the exhaust is also a key tuning aids for the engine and highly influential on aerodynamics too. So here’s a quick dive into some of the unseen technicalities and details of the F1 exhaust from the normally aspirated V8 era.
It’s been a source of many a joke, that High Tech F1 cars run with a piece of wood bolted underneath them. The plank as it’s known by the regulations, is in fact a bit cleverer than a mere piece of wood. Its aim to prevent excessively low ground clearance in the wake of Senna’s 1994 crash has been challenged by the designers and now teams regularly run the tip of the plank along the ground.
A rarely seen part that came with some other R&D mock up parts is this Hydraulic fluid reservoir. This small unit keeps the hydraulic pump fed with fluid, although the example I have a 3D printed part and the finished part on the race car is more likely to be a carbon fibre piece.
Sometimes the level of engineering in F1 is best described by the smaller simpler parts, an example of this is the humble suspension mounting. This part being the point where the wishbone meets the gearbox to allow the suspension arm to pivot around it spherical bearing. This example is a 2012 Sauber C31 rear wishbone mounting clevis, but is typical of several similar clevises in my collection of F1 parts, albeit they appear to get a little more sophisticated in shape each year.
As F1 shifted from push rod rear suspension to pull rod, the packaging of the various compliant elements pivoting on it became more complex too. Here we can analyse in depth the lower section of a Sauber C30-C31 rear pull rod rocker from 2011-2012. This part pivots in a subframe mounted inside the gearbox, to operate the side springs\dampers, heave spring\dampers and anti roll bar.
It’s common for teams to buy in certain parts from third party manufacturers, these can either be manufactured to the team’s design or from the manufacturers. One example is the steering universal joint (UJ), a recent acquisition to my collection of F1 hardware is a Pankl part used by Red Bull Racing. The steering joint allows the high mounted steering column angle down to the steering rack, whilst still allowing smooth rotational movement of the steering column. Continue reading
Set up sheets have always fascinated me, they are the document used to list the hardware and set up to be used on a racecar, before its dispatched from the factory. My latest acquisition has been three Arrows set up sheets from 1997, covering three separate tests with three different drivers at two different tracks within the space of four months. It gives us insight what is included in the set up sheet, the actual set up differences and provides of a story of the team’s year.
Much like the shift in road car steering, F1 steering is now power assisted, with the hydraulic power steering rack now has been standard for many years. Integrated as part of the cars high power hydraulic system, the rack is an essential part of the cars set up. Without it the current suspension geometry at the upright would be impossible to steer without power assistance. Like all F1 hydraulic solutions, the rack is a simple solution, made possible by finely engineered details.
F1 cars still carry batteries other than the ERS Energy Store, while the tech in the ERS is top secret and hi tech, there is lesser battery tech under the skin of the car. Two other batteries are hidden away fulfilling critical roles, although their tech and installation is far from the cutting edge seen in the energy store.
Despite a huge ERS battery sat in the car, there remains a conventional 12v battery to support the car’s systems when the motor isn’t running. Even pre-ERS this battery was a Li-Ion cell type tucked away within the sidepod. Typically, this is a motorsport specific Li-Ion type from a number of common suppliers (Varley, Braille), but this Marussia technical drawing shows how the unit is ‘dressed up’ to suit an F1 installation. The basic battery has a carbon moulding bonded over it, with a Military-style multi-pin motorsport connector to join it to the car’s electrical system. This carbon lid hides the permanent cabling connecting the battery terminals to the connector.
From your digital kitchen scales, toy remote controls and smoke alarms, the aged 9V cell with its clip on connectors is an unlikely F1 part, but every car carries one and is fundamental to the car and driver’s safety. Unseen, the 9v Cell is part of the car’s fire extinguisher system, fitted in case the electrical system fails to provide the system with enough energy to set off the extinguisher. The positive terminal connection and voltage of the humble 9v cell is ideal for this situation, so everyone can now say they have F1 technology in their house!
F1 rightly occupies a place at the top end of engineering and technology. But that is not to say that F1 cannot take inspiration from most unusual of places. Many who follow this blog have inevitably been involved in the technically taxing assembly of flat pack furniture. Unbeknown to us the clever fasteners used in straight and right angle butt joints are equally at use in F1 cars!
Fastening thin bodywork or even larger structures like engines together on an F1 car is always a problem. Stiffness and lightness are the key aim, but carbon structure of the car is an obstacle to both at times. As these joints tend to work in tension, part-A wants to be bolted to part-B, tightened and then not fail when under load. An obvious way to do this is to has a threaded bolt going into a threaded insert. Placing a threaded insert into a F1 carbon structure is difficult, both as the insert invariably requires another metallic part to be bonded into the structure, then there needs to be enough structure to prevent the insert pulling out or the insert’s threads failing.
This problem is analogous to bolting crumbly chipboard sections together in your Ikea furniture, the point loads of a threaded fastener do not work in chipboard and the low cost aspect of flat pack furniture deters the addition of stiffening threaded inserts into the otherwise cheap chipboard matrix. So we see joints made up of fasteners going into larger diameter barrel nuts. The barrel nut provides the stiff threaded structure but its large size means it spreads its loads effectively into the chipboard, reducing the point load in the chipboard itself. While a fastening solution good for tension, but not good for torsion, we also see these flat pack fortunate joints aided by wooden dowels to prevent the structure twisting and pulling the barrel but fastener in ways that might break the chipboard.
Just the same approach is used in F1, the strong tensile joint of a bolt into a barrel nut perfectly suits the issue with carbon fibre. Now a large diameter hole is needed in the carbon, no metallic insert is required, just the replaceable barrel nut. So we can see the engine is bolted into the back of the Monocoque with just such a flat pack solution, thin sections of bodywork such as the rear wing endplate mounting are joined with barrel nuts, creating the stiff aero assembly without the need to compromise the thinness of the parts for a stronger bolted up assembly
Cam lock fasteners
Another flat pack feature that translates to F1 cars is the way the nose bolts to the chassis. We often see damaged noses replaced in seconds at a pit stop with the mechanic quarter turning a fastener and the nose easily being released. Again like the issue with joining up assemblies in tension, the nose and moncoques do not want to have large threaded assemblies inside them. So the F1 nose is mounted much like the quarter turn fasteners used for right angle joints in Flat pack furniture.
These consist of a pin and a cam fastener, where a rounded end feature of the pin slides into the tapering slot around the barrel shaped cam fastener. When the cam is turned, the slot pulls the pin in tightly towards it making for a stiff assembly and the taper provides enough grip on the pin to prevent it loosening. Usefully for quick nose changes, the reverse process to loosen the joint, the pin is ejected by the tapered slot helping the nose come off the front bulkhead.