It may sound obvious, but in the motor sport industry only one thing is important, and that is winning races. Everything they do, everything they buy is geared to that goal, and that includes the many connectors scattered around a car’s body.Connectors have to meet military-like specifications in terms of reliability and there are constant pressures on the manufacturers to reduce the size and weight. Interestingly, when it comes to Formula One, the weight reduction is not to lower the overall weight, as most of the cars come in at below specified weight anyway and have to have weights added. What is important is where the weight is on the car.
If the designers can reduce weight spread around the car, they can replace it with weight low down in the car, reducing its centre of gravity and thus giving it better road holding capabilities.
As mentioned, the connectors themselves are variants on military and aerospace specification connectors but modified to reduce the weight without compromising the performance. Just changing the shape to a custom design is one common method.
“But it is challenging to make them smaller,” said Mark Richardson, business manager for autosport at Souriau. “We have the smallest connector in the market for sensor applications and that has stretched the know-how of what is available.”
A typical Formula One car will have about 130 sensors, so even saving a small amount of weight on the connectors to the sensors can add up to quite a large saving for the car overall.
“Our sensor connector for this year is 33 per cent lighter and smaller than the previous model,” said Richardson. “We have used lighter grade insulating material. We have developed machining capabilities to make smaller components. It is all about manufacturing capabilities.”
The alternative to making a connector smaller is to have more contacts per connector so that fewer connectors are needed. Thus some of the connector makers are looking at smaller versions of standard D connectors; these are known as micro D and nano D.
“With these, you can take a connector the same size as a standard connector and get four times as many contacts,” said Peter Boreham, general manager of Filcon. “So you save space and weight.”
Difficult to work with
But Gary Norman, principal technical engineer at Beru, one of the companies that uses the connectors to make the wiring looms for the cars, has found some of the high-density connectors difficult to work with.
“By the time you populate them with wire, and add splices, and put some resistors and capacitors in there, there is very little space,” he said. “This can be very difficult if you want to change things.”
Also, D connectors often come pre-wired, and all the wires are the same length, so companies such as Beru have to specify the length of the longest wire and then cut back the others to fit. This can be fine unless again something needs to be changed, as often happens with Formula One, even during a season.
Hypertac is one of the companies that makes D connectors for motor sport. Managing director Giuseppe Lancella said that the firm does make connectors with removable contacts for testing purposes but then produces a final connector with the wires fixed once all the testing has been done.
“The wires are very expensive,” he said. “There is a lot of work to cut the wires to requirements, so we have connectors with removable contacts that can be assembled in the field. But for reliability reasons, they prefer these only for testing. But when the design is finalised, they prefer to have a product completely assembled and wired. Sometimes we ship this using a fast courier just a couple of days before the race.”
No required tests
One of the difficulties – some see it as a benefit – of motor sport is that there are no required tests for components such as connectors to go through. Obviously, the manufacturers will do some basic testing, such as checking the waterproof seals and so on, but none of these are required.
“The acid test is to mount it on a car and see if it works,” said Richardson.” Any fault with the connector will immediately flash up on the telemetry system. The teams tend not to rely on test data we provide.” Typical faults at this stage normally involve the connector not being able to handle the car’s vibrations and thus the connection becomes intermittent.
For a brand new connector design, the norm is for this to be first used in a non-critical part of the car, one that will not affect the result of a race. If it survives a racing season there, then it would be considered for more crucial areas the following season.
This is fine for connectors spread around the chassis of the car, but when it comes to the connectors on the engine itself, most Formula One teams have their own test beds. A top team will produce around 100 engines a year, but only use around 15 of them in actual races, the rest are for testing purposes.
“The test engines are used to fine tune different aspects of the engine, and that includes the connectors,” said Richardson. “They go through some very rigorous testing to see if they are meeting the requirements.”
The problem for the connector manufacturer is that often they do not know exactly what tests they will go through or the actual design of the engine. The full specifications are kept within the team for secrecy reasons – leaks of such information are treated very seriously in the motor sport world as was seen by the very public row between McLaren and Ferrari last year, which eventually led to McLaren losing its constructors championship points.
“There is a high level of secrecy,” said Richardson. “We don’t know the full specifications. The best we can do is put them through military specification tests. The tests that the teams do are kept behind closed doors; we just know if it has passed. They will feedback information to help us improve the design, but the information is very specific. They will tell us the exact frequency it failed at rather than details of the full test.”
Formula One development also moves at a rapid pace with the car often from one season to another being completely changed, giving the connector manufacturers something like a three to four month window to develop and test a product.
This will become more difficult in the coming year as teams wrestle with the new kinetic energy recovery systems (KERS) regulations that are to come into force in 2009. These have come about in response to environmentalist pressures and they demand that the cars feedback some of the lost energy from deceleration into the car to give boosts of power for limited times.
This will take the connector manufacturers into a new area for Formula One. Typically, the amount of current flying around a car is quite small, about 30 to 40A, but with KERS this will jump to 300 to 500A and the connectors will have to handle that. To add to the problem, there is no set way for KERS to be implemented; it is being left up to each team to come up with their own design. For connector makers, this means there will be as many different connectors as there are teams.
Obviously, a higher power connector will have to be heavier, but one route some teams are looking at is to combine the connectors and cables of power and signals so the same connector can act as both. Shielding should not be a problem as the signals tend not to be at high data rates in racing cars and the current will be DC.
Author : Steve Rogerson
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