From Elise FAQ
Compiled by Dot
Although written for MGF owners, the following is an excellent resource on the available induction systems, ITG did not want to be included in their testing which is a shame as their system is arguably the best (but most expensive - so maybe not value for money): http://ourworld.compuserve.com/homepages/robmidgleybell/filter.htm
To summarise, the following induction systems were tested:
Panel Filters: Jamex, Ramair, K&N, Standard paper Cone filters: Ramair, Pipercross PX, K&N 57i, Pipercross Vector
The K&N 57i emerged as the winner. For the full details, and for suppliers, see the link above.
The Hurricane system was not available at the time of the test, it slots in between the K&N and the ITG system, is priced accordingly and has developed a good reputation since this test was performed.
After fitting a new air filter, you should reset the the IAC (Idle Air Control) Valve by pushing the throttle pedal slowly five times (with ignition on and the alarm demobilised).