BTCC Engineering

Since 2013 the British Touring Car Championship has run to the NGTC rules. The next generation touring car concept was introduced to control the costs of competing in this form of racing that had hit multi million pound budgets under the previous S2000 rules.

The BTCC has long been one of the world's most exciting and competitive championships and has attracted manufacturers and top drivers from around the globe. It has a massive following and aside from F1, it draws the biggest crowds both at the circuit and on TV.

NGTC basically defines a lot of the running gear of the car to a kit of standardised components. Only the bodyshell, engine  and the body styling kit can change between cars/teams. The engines are turbo charged 2 litre 4 cylinder  types with equivalency rules to ensure parity of performance.

So the room for engineers to find performance is severely restricted. However because the competition is so close (often only tenths of a second covering most of the grid) small detailed improvements can make big differences to grid position.

BTCC teams range from very professional manufacturer teams to very enthusiastic amateurs with a ton of volunteer help. When you are doing any serious race car engineering work it's very important to know what you are working from.  Touring cars tend to be hand built and parts made up ad hoc as the cars come together so knowing exactly what you have can be a problem.  In F1 for example every single part will be CAD modelled allowing you a lot of possibilities for analysis and simulation.

So I think it's really important to try and understand what you have and so part of that is to build CAD models where possible in the case of my current project I've assembled CAD models of all of the standard kit components to begin with. The team have a limited budget but also practical requirements for spare parts and the desire to try and keep up with developments.

The flat floor at the front creates an aerodynamic splitter element and is one area that can be changed by the teams as it must fit an offset of the front bumper/air dam plan view silhouette. As with all race cars you are looking to reduce the weight and keep it as low as possible. This team needed spare floors and at the same time we've reduced the overall weight and made the floor area larger to the extent allowed by the regulations.  As the front air dam creates a high pressure area in the front of the car and on top of the splitter with a reduced pressure underneath you end up generating down force.  As down force comes from the pressure difference between top and bottom of the splitter multiplied by the area of the fool that that pressure acts upon, the larger the area of the flat floor the better. In this case we've added about 1300 cms Sq so hopefully that and 3kgs less weight will make for very cost effective performance improvement.

The other part of this first stage of upgrades is to redesign the body kit to further reduce weight and decrease drag and increase down force.  We don't have the budget currently to conduct wind tunnel development and whilst we have CFD capability without the budget to scan the cars shape and create CAD data for this we can't make much use of it. So we are using experience and common sense to try and make improvements in the area.

As the car is currently 3 kgs over weight and front weight balanced we are aiming to reduce the weight of the front bumper, wings etc and then if required to make up the minimum weight with ballast low down in the rear of the car. As the cars race performance is dependent on how they use and abuse the tyres, balancing the front to rear weight split to equalise tyre use is likely to be important for overall race performance.

How Autosport GP Engineering bring dinosaurs to life.

How do you take a design brief to create a realistic 3D Jurassic Park Velociraptor and produce a pair of 1m tall figures in just 4 weeks including Christmas?

Well the answer is a lot of hard work, skill and a not inconsiderable amount of advanced technology.

Equinox Products of Whitstable regularly produce fibreglass figures for Harry Levy Amusements of Broadstairs. They came to us in early December with a sketch of a new machine they had to have displayed at a games and amusements exhibition  in the 2nd week of January. Under normal circumstances you might expect this to be a 4 month project not a 4 week one, especially as across Christmas all suppliers are closed.

Normally with these projects someone will produce a 3D CAD model of the end figure, or a skilled artist might hand carve it. In order to make a realistic looking dinosaur a particularly skilled sculptor would be required and they would need plenty of time, both of which are in short supply. In order to create from scratch a 3D CAD model with such detail is a very time consuming project and requires extremely experienced CAD surfacing designers.

Once a CAD model has been produced patterns in dense foam are produced. These patterns, are essentially the finished items only split into sections so moulds can be made from them. 3 axis CNC machining centres that are computer programmed by extracting the geometry directly from the 3D CAD model, are used to produce the patterns.

Moulds are then produced in such away as they can be split apart to extract the fibreglass finished figures once they are laid up inside. In each of these processes you can see there is a lot of time spent producing items that are just links in the chain towards being able to produce a final figure, and then a production quantity of them, in this case 62 items across the first few months of 2015.

Four weeks including Christmas, made this traditional approach a total non-starter. So a new approach had to be taken. We sent out for a model toy dinosaur figure and it was optically scanned. Optical scanning is an extremely accurate (0.02mm resolution or higher) method of capturing 3D geometry. It's used for reverse engineering and for inspection because it can capture, for analysis, forms that are hard to capture by other methods.

The resulting data from the scan is in the form of a mesh of data points representing the form of the dinosaur toy. Unfortunately the original pose of the toy was not suitable for how it was required to fit on the finished machine. We used a combination of advanced software, similar to that used to produce CGI movies, to re-pose the figure, and then cover the mesh with CAD compatible surfaces that can then be used for manufacture. Some mechanical fixing elements were added in the 3D CAD model at this stage.

Finally using this CAD data we 3D printed in plastic the finished dinosaur. However being over 1 m tall our 3D printers couldn't print it in 1 piece, but, luckily the software allows us to split it into smaller parts and add socket and pin details so that it can be clipped and glue back together after.

Three were made in total two for the exhibition and a third was used to make the GRP moulds from so that a production run of 62 figures can be produced. We were thinking of creating a bit of a stir in the local press by burying some spare parts in the beach at Whitstable and seeing what the reaction was when the were uncovered!

Can we help you with a similar challenge? If so then please contact me on 01227 392840 or autosportgpengineering@gmail.com

How Marussia might be able to get on the grid for 2015

So news has hit today that the hopes of the Marussia F1 team (now Manor) have been dealt a huge blow by the veto from Force India to them using the 2014 car although it doesn't comply with 2015 regulations.

As there is reportedly over £30 million in prize money from last year at stake I can imagine how the teams backers are desperately thinking of ways to get a 2015 compliant car ready asap. I've also been thinking about how you might be able to short cut the process so they can have a car ready in time.

The apparent stumbling block is that the front bulkhead on the monocoque needs to be 50mm lower than in 2014, so you need a new monocoque design. Marussia apparently had a 2015 design complete and pictures are being circulated of a wind tunnel model. So most of the thought process for the nose and monocoque has been done, but, there isn't time to manufacture a new one.

In order to manufacture a new monocoque you first need to machine a pattern out of high density foam or aluminum from the CAD model. This is several days/weeks of machine time. After this you have to make carbon fibre moulds from the pattern, again many days work, and then you get to make an actual monocoque. So you are looking at a vast amount of time and money both of which they don't have.

However there are ways to short cut this process. They are going to have to retain as many parts as possible from the 2014 car, so I would want to choose a point along a 2014 monocoque and cut it off (figuratively) retain everything rearwards of this point, and blend the rear of the 2015 nose design they already have into this point on the 2014 monocoque. What this allows you to do is reuse most of the monocoque pattern from 2014, saving machine time, also you can cut the moulds back to this point, remould a return flange on them and then the majority of the moulds can be reused. You can then machine a small pattern which is the blend from the 2015 nose to 2014 tub, make moulds from this with return flanges that can bolt onto the main section, and away you go, you have a new set of moulds from which a 2015 tub can be made. Reducing cost and time by at least 50%.

Unfortunately for them the external shape of the monocoque is not the only problem to overcome, packaging the steering, pedals, brakes and front suspension into this new space with the minimum of new components will be an equally difficult challenge, but if they are true racers where there's a will there's a way.

It might not be a typical F1 solution, or result in a particularly attractive car, but that's the least of their worries at the moment. I'm sure we'd all like to see them on the grid however they manage it. They clearly have resolve to keep trying even after the apparent death, after all I'm typing this blog one of their PC's that was sold off at the disposal auction.

Darren George
ex-F1 Design Engineer