I know it's recommended to idle the engine for a minute or so before turning it off, but I'm wondering whether this is always necessary, or only after spirited driving. If, say, the last few minutes of my drive home are under 2k RPMs, do I still need to let it idle for a minute or so? If I understand what the cool down is for, wouldn't keeping the rps real low for a few minutes just before shutting the engine off do the trick, regardless of whether this while driving or parked? Or am I missing something?

 

My take on this is that I try not to run the motor under boost for the last mile or so ( light throttle, less than 3k rpm ) so that the Turbo won't be spinning at high rpms, and the engine will be getting more cooling than if it were just stood still in a parking lot. Then once I park I let the engine run for 10 seconds or so and turn it off. The only time I let it idle for 2 minutes is I've been doing some "spirited" driving and haven't been able to cool it down like above. But I bet everyone has their own superstitions on this one.

 

i let the car cool for a minute or so (for regular driving, more if i was driving it hard)... got kind of old so i got a HKS Turbo Timer, does the job for me (along with a few other things)

it's a pretty nifty device that's there for you all the time.

 

my general rules...
normal, slow driving, no boost - 30 seconds (takes that long for me to get my gear out of the car.
boosted fun driving - 2 min and up - depends on what I was doing.

turbo timers are great. I've had one on my GSX for years now. Best part is setting it for 10 minutes and locking the doors when you go into a quickie mart on a cold day.

 

here's a question as far as the TT's... do you have to leave the car in neutral when you get out of the car if you are using a TT...?

 

If you want the car to stay where you left it, you will need to leave it in neutral when using a tt.

 

If you want to car to run you have to leave it in neutral.

 

For you guys who have experience using turbo timers: how often to you hear of tt-ed cars being broken into by thiefs who think the car was left running and is an easy target? I know that once they take the e-brake off, the car shuts itself off, but you're still stuck with a broken window and missing stuff.

If there a way to let thiefs know they are wasting their time, that the car can't be driven? Maybe some sort of steering wheel cover saying, "Stop thief, it's not what you think!" like some brake pedal locks have.

Just wondering...

 

I live where I can glide for the last half mile.
That helps keep air going through the car too.
I have a hard time believing that people sit in their car for 1 or 2 minutes while it idles.
If you don't drive hard you don't need to sit in your car for 2 minutes.
When at the track I drive around the infield after a run to cool the entire car including brakes. A little airflow goes a long way.
I can't believe how many people just park it after a hot run!