SA Mike

How long should I let the car cool down after running it? Having previously owned turbo charged cars (Rx7, Lotus Esprit) I know that it is important to let the turbos cool for at least a couple of minutes before shutting it off. Is that the case with this tubo set up. I've been doing this since I bought it.

PTurbo965

It depends on how hard you are driving it prior to turning it off. At the track, I would let it run a while because the temp of everything on the car is up higher than normal. On the street, I assume you are doing some fairly easy driving as you get close to home. I think that time alone would be adequate to solve any turbo oil temp issues. If you reach 6200rpms in your driveway, then adjust accordingly.

Megatron-UK

I've owned at least half a dozen different turbocharged cars and none of them have required any time parked up to cool down before switching off. It's about the worst thing you can do anyway if the car is very hot - just let it sit and idle... heat soak of every component!

The best answer is to say that you shouldn't really be using boost for that last mile or two of your journey anyway. I don't think anyone's neighbours appreciates sports car owners who fly past their homes, slam on the anchors and then turn into their own driveways.

Just be sensible for those last few minutes on your way to work or coming home, that's all.

Kevin

One minute at the very least.. Two minutes would be nice.

Go take a heat gun and point it at your heat exchangers and turbine housings.. It will range from 600-800 degrees.. The transfer of heat to your turbine wheel sucks the life out of the turbine side sealing rings and takes a toll on your bearings. I have posted in the past, where the hot shutdowns will literally silk screen blueing marks from your bearings and oil supply holes. Many comparisons from other turbochargered cars aren't good due to there watercooled bearing housings..

SA Mike

I have no idea what your talking about

dholling13

Cool down or be ready to buy one of Kevin's high flow units.

eyue

I would let it idle a minute or 2 before shutting off....

Megatron-UK

Sorry, but what exactly is the oil doing while you're sitting there idling? There's no air flow past any components when you're sat still.

Yes, I agree, shutting off when you've just been on boost and come to a standstill is idiotic, but I have seen no evidence at all that a turbocharged car needs to sit and idle before turning off - just drive sensibly on your last few minutes, that's all.

... and don't get me started on 'turbo timers' .....

38D

The rich A/F mix is cooling down the exhaust temps and thus cooling your turbine. Very diff than a water cooled car. And Kevin is the "the guy" in the US for building air cooled turbos, so he sees tons of evidence every single week.

Now I will agree that driving off boost for 3-4 mins is another way to cool down, but for some of us that actually race these cars, that is not an option.

Megatron-UK

Completely agree when racing or tracking your car - unless it's some kind of organised session with a cool down lap, then it's not an option.

SA Mike

Thanks Kevin, I'll just keep letting it cool down for a minute or two depending on situation. My Esprit like most, ran very hot so it was a must, just wanted to see this turbo being air/oil cooled was any different

eyue

I believe whether you are driving a turbo or not, let it cool down for a while after hard driving is a good practice !

asimler

This maybe slightly unrelated but can anyone confirm if the HVAC fans, if necessary, keep running if the car is hot enough even after switch off. The fans being the ones I believe are just in front of the rear wheelarches. Ive never heard mine running but for some reason thought I'd read that somewhere.

Even if true - would it help the turbo in any way cool down?

nathanUK '81 930 G50

My alarm has a turbo timer built into it. Very useful.

Boeing 717

I think it is important to let it idle, i usually coast down a hill to my driveway and start timing by the time it gets in the garage its been about a minute. On the Boeing 717 we get a message that sais "engine cool" three minutes after landing and only then can you shut it down so i think the principle is the same you have to let the bearings cool down.

JERRY