Ahh - no wonder none of the references to Vipers on TFs mentioned all the hassle I had
I'll make sure I make that clear in my 'how to'
Difference on Mk1 F is really obvious - idle went up to 1200 rpm until I reset the the system, so quite a bit of fuel economy.
Not surprising really:
Old system: over 3m long, 540 degrees of bends and 60mm diameter intake in engine bay.
New system: about 1.5m long, 180 degrees of bends and 76mm intake in nearside vent.
So basically, in the MK 1, the new system is shorter, less convoluted, with larger intake and better location
But much more important is the massive improvment in throttle response and and the wonderful sound - my 19 year old son couldn't stopp grinning when we took it for a test drive
BTW does anyone know what the situation is regarding access to the air vent on a Mk2 F?
Ok - I'll put that info in the 'how to'