Use when ambient air temperature is high and you're 'going for it' (ie. a hot day on your local best A road). Nothing noticeable physically but have had a heat probe on it and ytemperature drops by 2 degrees celcius instantaneously |EQU| more bhp (not a lot but enough). There is talk of someone designing a pressure switch which pops it on automatically but I don't use it enough to warrant one of those.
I usually use mine if I've been dawdling through slow traffic on a hot day and the road ahead is starting to clear and I'm getting ready to perform one of my 'overtake 7 cars in one go' manouver http://www.ltregister.force9.co.uk/graphics/Happy.gif border|EQU| 0 align|EQU| middle >
Got 3K then fit the Motec and map it to come on ,on auto when you want.
Speak to ADI Moptorsport in Leighton Buzzard. Ask For Brian he is running two Grp N evos in Competition, is building a GrpA,He is Ex Ralliart,and used to Run K Sport (when they were Good)