With the FOM world TV feed now using on-board Infrared (IR) cameras, it’s been interesting to see how the tyres temperature changes around the lap. But in Korea we were treated to a rear facing IR camera on Mark Webber’s car that showed the front of the T-Tray splitter warming up and staying hot around the lap. This image helps to highlight both the cars set up and the construction of the car around the front of the T-Tray. Many fans jumped to the conclusion it’s the plank itself running hot under the car, but it is in fact the titanium skid blocks conducting heat through to the floor mount.
IR cameras have been a feature on F1 cars for over ten years, when I first noticed McLaren openly testing with Thermoteknix cameras. Since then the technology has matured and team may even race with IR cameras installed to monitor tyre temperatures across the tread. Now the cameras are also used to confirm the exhaust path over the sidepods and floor, in order to be sure the exhaust is blowing where it’s expected to be.
The FIA cameras are similar, but the temperature gradient is simplified to a few colours within a narrow temperature band, so as not to give away too many of the team’s secrets. Pointing them at areas other than the tyres shows the unusual temperature signatures around the car, hot areas such as brakes, exhausts and radiators show up in colour on the otherwise grey image.
The front of the T-Tray on Webber’s car, appeared surprising to many fans and theories of KERS batteries and coolers circulated the internet. In fact the hot spot was a metal reinforcement mounted above the T-tray. This component is part of the system to resist the FIA deflection tests for the T-tray. The protruding carbon fibre splitter is relatively flexible, but to meet the FIA application of a 100kg load up under the tip off the T-tray requires stiffeners to be fitted inside the hollow splitter section. On the red Bull this is formed of three parts; firstly the flat plate extending from the bottom of the tub to the front edge of the splitter. This plate is some 20cm to reflect the FIA that can be applied up to 10cm from the cars centreline. Then there is the vertical strut to help support the front edge of the floor and lastly a metal plate across the top of the splitter edge that connects all the parts together. It’s this last plate that can be seen on the IR camera.
On its own it would not be hot, so the source of heat is from the titanium skid block under the floor. Beneath the floor is the cars legality plank, this is aided by several circular Ti skid blocks that fit into holes in the plank. Its these skids blocks that scrape the track and teams will tune ride height and suspension setting to ensure they skims the track, but do not unduly wear. Obviously excessive wear would be a legal issue, but they are remarkably resilient to constant light grounding. On the front of the plank there’s a single central skid block which bolts through the reinforcing plate and the top plate. So the tremendous amount of heat it generates passes through the fastener into the other components. This conducted heat is what’s seen on the IR camera.