[Richard L]

Putting a small nozzle upstream of the supercharger is very effective.

If you are cruising at medium to high speed whilst the throttle opening is small, The heat gererated by the S/C's step-up gears and bearing, coupling with air/rotor surface heat riase due to friction is quite surprising high - it can reach 100C+!! Once the throttle is opened wide, the increase air flow brings the charge temperature down drasticly but it wil take a few seconds.

The first pocket of high temperature air entering the combustion chamber will more than likely to set -off a detonation sequence and it will normally continue. The engine's knock controller will immediately take action and retard the timing and the power loss is immenent. All this happens within a second or so but it will take time for the engine management to re-advance the timing to re-gain performance.

The way to overcome this condition is to prevent it from happening in the first place. A small trickle of water upstream of the S/C in the region of 75-100cc/min will acheive this cooling effect.

Great care has to be taken in winter when you spray water/menthanol mix onto a large surface area of the rotor, it will freeze and ruin you S/C for good. It is better to disable this spray system in cold winters wirth sub-zero temperatures.