In my last post we looked at the Engineering which “Team Dynamics” have but into preparing there shell by examining the Photos which Team Dynamics had published on Twitter. In this Post we will we look at the enginering behind installing a roll cage, again we will be examing a Team Dynamics photo. The photo was kindly published by Mat Neal Via his Twitter account (@ MattNealRacing)
In Touring cars a roll cage has two main functions the first and most obvious function is to protect the driver in the case of a crash or a roll, the second slightly less obvious function is to stiffen the shell and to to tie the suspention points together.
It is surprising how much deflection and twist a standard uncaged production car has. A race car with a flexing shell would be difficult to predict and setup for the race track and as a result would be slow.
The balancing act when designing a roll cage is the trade off between safety, stiffness and weight. Obviously a cage has to be strong enough to protect the driver in the event of a crash, has to be Stiff enough to not allow body flex but also as light as possible so as to allow the car to be competitive.
With the NGTC rules meaning that all entrants suspension will be identical the shell that sits between the specification and ties it together will be more important than ever and could easily make the difference between a good car and a poor car.
Although Team Dynamics can demonstrate considerable skills and prowess in Motorsport engineering I believe it is likely that they will have out sourced the cage design to a specialist company such as “Custom cages” or “Safety Devices” for the cage design to ensure that the best solution is utilised.
There are two main materials which cages tend to be constructed from “T45” High tensile carbon manganese steel and “CDS” Cold Drawn Seemless Carbon steel.
T45 is stronger than CDS meaning that a thinner tube wall thickness can be used to acheive the same strength cage as CDS and as a result a lighter roll cage can be made. T45 However is significantly more expensice than CDS.
Team Dynamics will definitely be using a T45 roll cage.
What else can we see from dynamics photo? I have highlighted the following points on the photo:
1, The impressive triangulation of the cage can clearly be seen. Also the diagonal bracing of the car from left to rear can be seen to be positioned quite far toward the rear of the car. Its positioned to the rear of the “B” pillar of the shell, this will allow the driving position to be much further back that in a standard road car. The drivers shoulder will probably line up with or be slightly behind the cars “B” pillar.
2, The cut out sections highlighted in the last post have been replaced with bespoke sheet metal fabrications increasing the space available for the rear suspension and rear wheels. The amount of shell which has been cut away is also evident in this photo as the cut away encroaches into the door shut area.
3, The full tank can be seen to be located in almost in the centre of the car. In past generation touring cars the Tank has been located further towards the rear of the car. This was to try to help balance the inherent front heaviness of a front engine, front wheel drive car. However it was found in the past that the handling of the car was adversely effected as the tank emptied during the race. Locating the tank in the center of the car helps the cars handling be predictable on both full and empty tanks.
4, The location of the fire extinguisher can be revealed to be positioned next to the fuel tank this moves away from some teams tradition of installing fire extinguishers in the passengers foot well. Installing the fire extinguisher in the center of the car will slightly increase the length of hosing needed but will help with the cars COFG. The rules mandate at least one nozzle directed into the engine bay, one at the driver and one at the fuel tank.
5, Team Dynamics impressive attention to detail is demonstrated here, where you can see the exact spacing of welds around the door shut has been measured and marked out for the fabricators to follow, creating a very neat uniform stiching of weld.
6, The rear cage points can be seen to continuing to the rear floor of the shell rather than to the traditional rear damper mounts on top of the rear wheel arch inner. This is notably different to the S2000 specification cars which used macpherson struts suspention, this is due to the civic now utilizing the NGTC double wishbone rear suspension, the cage will tie into the spec NGTC subframe at this point.
The next part of the Team Dynamics NGTC build will be to paint and assemble the shell.
I’ll be back in my next blog to continue to talk about the engineering behing touring cars…
Any questions or comments feel free to contact me at firstname.lastname@example.org