cool down turbos?

I have never owned a turbo before and don't have an owners manual. Should I let the turbos cool done a little before shutting off the car?
Also, what octane gas should I run?
Thanks.

I assume you have a vr4? If so, 91 octane or better. As far as turbos cooling down, my answer is yes, you should definantly let them cool down. When your turbos are running hard, the bearings are spinning like crazy and the oil is extremely hot. If you just turn your car off after a hard run. The hot oil just stays inside the turbo and essentially bakes your bearings as it cools and can leave gunk that shortens the lifespan of your turbos. So allowing the car to idle for a bit before turning it off allows oil to continue to circulate through the turbos as it is cooling, so it doesn't just sit and bake. Some say 30 seconds is enough. I personally think spending 80 bucks on a turbo timer is the best way to go. It allows you to take the keys out of the ignition and leave the car and it automatically detects how long to leave the car running, and then shuts it off when cool down is complete. Check out www.3sxperformance.com for a turbo timer if you're interested. I have HKS and am very satisfied. As I said before, some say 30 seconds is plenty of time, I let the turbo timer decide. There have been times that it has 'decided' my car needed up to 5 mins of cool down(after a 3 hour drive with speeds exceeding 100mph 90% of the time). I personally would rather be safe than sorry, so I go with what the turbo timer thinks, rather than just 30 sec. Hope that helps, and welcome to AF.