check your the TEMP gauge on your dash... you shouldn't boost 'til its at its 'running temperature' i think its a knotch above the first line is where you should be.

as far as cool down... as long as u haven't driven your car 'hard' you should just be able to turn it off right when u park. if the stock turbo needed a turbo timer it would have came w/ one.

i think even if u have an upgraded turbo... aslong as u haven't driven ur car hard... should be fine.

but if u think you need a turbo timer... cuz of cool factor... hey! i'm all for it!

 

I warm my car up for like 5-10 minutes, so that the needle is above the lower line for at least a minute or two.

For cool-down, I'll let the engine idle for at least one cycle of the electric fan to cool the radiator, and then shut it down once the fan stops.