Is it necessary to let the turbo cool down when you're using little to no boost?

In a situation where you are using the turbo but not in the final 5-10 minutes of the trip, is a cool down necessary?

 

Not really. If you drive it pretty hard then 30 seconds should be utilized. If you drive it super hard then 1 minute should be long enough for it to cool down.

 

our turbos are water-cooled, correct? so that would mean a better efficient cooling i guess

 

usually in the last 2-3 minutes before i arrive at my house, i try to stay of boost and then when i park and idle i wait until the fan starts and when it stops i turn off the engine...

 

30 Sec Should Be Ok

 

If I drive around with little boost I just shut off right away.

If I've been driving around with boost constantly/ often, I let the car idle for about 20-30 seconds and shut off.

Our turbo is water cooled so there really is no need to let it idle if you have not been driving aggressively.

 

I thought the cooldown was for the oil in the shaft bearing? Being water cooled will not help keep fresh oil in this bearing.

No, you don't need to cool down if you don't drive hard just before the end of your trip.

 

You are correct.

 

I try to always give the turbo 10-15 sec to slow down to idle speeds, unless I'm really romping on the car and then I'll let it idle or drive normal for the last couple minutes of driving.

 

I would say as long as you don't go full boost during the 5 minutes before you get to your destination, just let it idle 30 seconds. If you do go full boost and what-not then you need to park, just cool it off for like 1 minute

 

well even tho are turbo's are water/oil cooled still after beeting on the car everything is still real hot. did you no that the hottest point everything gets is 10 minutes AFTER you shut the car off??? well its true. so for easy terms lets say at 3 min of idle your car is at 200 degree's. now after 10 min of it being shut off the hottest point lets say gets to 250 degree. now if you beet the **** out of the car and then shut it off it was hotter then an at idle temp. so now you shut it off at say 250. ten min go by and now your at 300 degree. get my drift. its not to scall but this is how it works. its best to just let it cool. average cool time on a beeten run is about 3 1/2 min. i have my tt set to 4 min just to be extra safe. weather you think its needed or not well it does help wheather you think so or not. .

 

I did not know that I guess I learn something everyday about my car!!! thanks for the info
and to the original post I would just buy a turbo timer. I bought 1 and all you go to do is set it and it will idle the car for you.

 

i thought water cooled turbo did not need a cool down period
i know on garret's web site it stated there water cooled turbos do not need a cool down period

 

Please tell me you are joking! You are taking an extreme case and turning it into the norm. The best way to cool down a turbo car is to drive it with little to no load before shutting it off. This is easy to accomplish if you have an EGT and if you are not EGT equooied you will just have to guesstimate how much time is needed to cool the "hot" parts . The main reason why a cool down is needed on a turbo setup is because stagnant oil inside if the center housing will "coke up" if the engine is shutoff after a hard run is made. This run will have to "hard" enough to make the manifold and front pipe glow like a jack-o-latern on halloween and not just the typical "blow some carbon out of the exhaust" run.

If you run your car so hard it needs to cool down for 4 minutes in a parking lot you should be sitting with it to check for CEL codes, over heating, fluid leaks, and weird noises. If you have the time to run the crap out of the motor, you should also have the time to cool it down properly. Most turbo timers are just like super noisy blow off valves....... just another item to make sure everybody knows your car has a turbo on it.