Cosworth's little black box

Data collection and analysis on an F1 scale

Data logging and analysis is not new in sailing, but the move into the marine market in recent years of British based firm Cosworth is. The company - famous for its F1 motor racing credentials now includes the Pi Research business and with it a spohisticated package of data logging hardware and analysis software.

Now commonly used at the Olympic level (product development has been with Skandia Team GBR) and at the Grand Prix level - America's Cup, Volvo, TP52 etc the Pi range of equipment can now be applied to racing boats to the 40 foot mark. This has principally come from the Pi Garda, the dinghy product, which now has options for a Tacktick interface or a generic NMEA interface for easy, common, data collection.

We saw the Pi Garda in action on a demo day organised by Tacktick and Cosworth on Jim Macgregor's Elan 410 Premier Flair - a quick lap of the Solent followed by some technical analysis afterwards in front of a laptop using the Pi Toolbox software.

The waterproof unit itself is pretty compact - just three iPhones thick in modern language, or 40 B and H in old. We located it on the chart table and hardwired it into Jim's Tacktick interface to collect the instrument data. Inside is amongst other things a GPS, accelerometer, battery, and a logging mechanism that can take everything Tacktick can throw at it at upto 500 times a second. It also comes with an on-off button and finally a 'data marker' button to put an event down on the trace of information.

After the sailing session, with the data downloaded onto a computer the power of the software is demonstrated and various aspects of your sailing can be investigated. Very cleverly video can also be brought into play and syncronised with the data and displayed on the same screen - either from onboard cameras, or say from a coach boat.

Click above for larger image

The screen is laid out in tabs with a default setting of General, Tuning, Tactics, Tacking, Gybing, Starting and Diagnostics showing the tip of the analysis iceberg at your fingertips - further custom tabs can be set up for your personal requirements. You are also able to overlay your track on Cmap charts which enables more specific race analysis.

The overall goal is one of setting up your boat and sailing technique to get the best VMG upwind and down and improving the manoeuvres such as tacking and gybing. The result should also give you strong confidence in your numbers. This isn't going to happen overnight, and is an iterative process - with techniques changed, logged, and if an improvement seen in the data, adopted.

One example cited to us by Cosworth's Simon Holloway, was some two boat testing carried out in Dragons. One boat had and aggressive fast style of tacking, the other a more graceful slower style. It had been difficult to separate the two on the water and following some Pi Garda analysis some interesting conclusions were found. In the end it was a mixture of the styles that worked best for VMG through the tack - so both boats gained after modifying their technique.

The Pi Garda system is priced at £1,850 so is a serious investment for the racer, but if you are committed to improving your sailing in this way, then the power and sophistication that it offers is impressive and will run through many seasons of racing. Some time will need to be spent on getting your existing instruments up to scratch with spot on true wind and boat speed inputs specifically - and the Pi Garda can actually assist with this calibration.

The investment may also be worthwhile for coaches who can take the unit from boat to boat as required. The data files are also reasonably compact and so in theory can be emailed off for analysis elsewhere.

Additional units include a clip on wind sensor for boats without one (such as an SB3 or Melges 24), and an IMU. This Inertial Measurement Unit brings pitch, heel, roll and associated rates into the mix. For the Grand Prix racer the Pi Sigma LLB is for you and costs in the region of £10k and includes its own wind processor.