When people state EFI conversion with regards to the RS they usually mean the EFI OFAB or OFAC management from the fiesta which has the advantage of getting rid of the metering unit and producing a more reliable system especially if you use the coil pack.. The disadvantage and reason that I did not choose this system is the fact that only a few people can map it such as Stu or Amhed.

The cossie management uses the parts of cosworth range and has available all the options that these can provide such as antilag, water injection, air injectors, launch control, coil pack and closed loop.
The ECU's are good value for money and keep their money on the second hand market... Best of all they can be mapped by a large number of people such as MSD, Turbosystems, Field Motorsport, NMS and Amhed Bajoo to name but a few...... it was this massive choice of experienced and renown company's all across the UK capable of mapping my car which help me decide.

Im so often informed that by people with 20 year old cars that 20 year old management is not suitable, and that there are better options however nobody has ever explained whats is so bad or unacceptable about Cossie management or what advantage a system which only a very few people are willing to map or have experience with is to me....

Management is only as good as the mapper and there is a wealth of knowledgeable people who are highly experienced with Cosworth management... its good enough that new features are being developed and released all the time by people like Stu

At the end of the day you should take advice of the person you trust to map your car and what they are experienced with

other unbiased opinions can be found from peoples signatures.....its like MTV pimp that tuner -- wheres Westwood