Tyre pressure system survives the force of Bugatti

Edited by the Engineeringtalk editorial team Dec 8, 2005

BERU F1 Systems is supplying its DigiTyre digital tyre pressure monitoring system for the world's fastest road car, the Bugatti Veyron 16.4.

BERU F1 Systems is supplying its DigiTyre digital tyre pressure monitoring system for the world's fastest road car, the Bugatti Veyron 16.4.

This is the system's first OE application and a rare example of direct technology transfer from F1 to road car.

With temperatures reaching over 100C and forces exceeding 2900g, traditional OEM tyre pressure monitoring systems (TPMS) would struggle to last necessitating the DigiTyre derivative.

The Bugatti Veyron 16.4's immense 736kW, 1250Nm torque, four wheel drive system and high top speed create the kind of arduous environment in which motorsport expert BERU F1 Systems has specialised for the past 12 years.

"This is a severe application, with the strain conditions exceeding those we witness in F1", says Managing Director John Bailey.

"On a production saloon the system normally experiences 2000g, but with 21in wheels, the Veyron 16.4 exerts over 2900g of centripetal force on the wheel electronics - the 35g weight in effect becoming over 80kg".

DigiTyre's components comprise wheel electronics, an ECU and an antenna system.

The wheel electronics contain a military grade battery, absolute pressure sensor, temperature sensor, accelerometer, microcontroller and radio transmitter/receiver - all housed in a very compact and robust Peek wheel housing.

By mounting this onto the rear of a modified valve there are no rim modifications and the installation becomes very straightforward.

BERU F1 Systems uses the pressure and temperature sensors together to identify a puncture situation, cross checking values with preset parameters defined at the factory.

There are two levels of alarm: soft warning - the tyre has lost a small but significant amount of pressure over time; and hard warning - the tyre has dropped below a minimum pressure level or the rate of pressure loss is large.

With the nominal tyre pressure set by a CAN databus message at the factory, the system works by compensating each wheel pressure and comparing this to its stored nominal pressure to calculate any pressure changes.

This approach avoids potential false alarms due to natural heating and cooling of the tyres.

System development hasn't stopped at the product itself.

The company is also providing wireless diagnostic equipment for end of line testing and dealer diagnostics.

Technology from the race track will also make life easier for technicians; in a race when wheel/tyre combinations are changed the system automatically learns when a wheel has been swapped.

The requirement for TPMS is being driven by legislation and tyre construction.

Modern rigid tyre walls mean that any drop in pressure will only lead to slight increased flexing of the wall when the vehicle is stationary.

Underinflation can lead to increased loading on the tread shoulders, reducing the contact patch with the road surface leading to difficult vehicle handling and loss of control on wet surfaces.

In response to tragic deaths and injuries attributed to tyre failure in the USA, Congress enacted the Transportation Recall, Enhancement, Accountability and Documentation (TREAD) Act in 2002.

Beginning in October 2005, and over the next two years, the act will require a pressure monitoring system for all US passenger vehicles and light trucks sold in the USA.

"We are expecting more and more manufacturers to look for turnkey, robust solutions".

"We are now talking to other OEMs, both high and low volume to offer a rapid, reliable solution to those selling to the US and other markets adopting the legislation", continues Bailey.