Originally Posted By Peter J
The Plus 8 has Aircon: it will be interesting to see how well it works, but as Peter says, sealing the inlet area of the heater box to keep engine bay air out is crucial.

I'm beginning to think that a raised solid edge for the heater box to within 1cm of the bonnet and sealed with a "D" rubber seal to meet the bonnet might be the answer.

The problem is you can't see or measure the gap with the bonnet open or shut. So it can only be done by trial and error using "witness chalk". Very, very tedious.

Of course a really expensive improvement is a new bonnet with the rear 4 louvres reversed, to scoop air in.

thinking
Put a cone of plasticine or bluetac or similar down and lower the bonnet. It will squash the plasticine to the gap height.
As for the louvres, how about catching the air that comes through the rearmost and ducting it to where you want it?
The rear louvres are in an area of positive pressure on a trad as the screen is an air dam,and the Plus8 may be the same?
Some time ago someone posted photos of bits of wool on his bonnet showing the airflow and identifying the positive pressure into the louvres.

Last edited by sospan; 11/01/15 12:47 PM.
Plus Four MY23 Furka Rouge