Cooling down turbo cars?

[recomdos]

I was out in my mates MR2 yesterday (which is unbelievably quick) anyway he says he has some sort of thing that allows the turbo to run when the engine is switched off for a couple of minutes, to allow it to cool down or something, thus prolonging the life of the turbo. (well that’s how I understood it anyway)

Now I've heard many people say you should let a turbo car tick over before switching off and others say it don't do anything. So now I don’t know what to think? When travelling to work or home each day I hit busier traffic and built up areas, so I ain’t going quick and certainly ain’t in boost, therefore I think of this as my ‘cooling down period’ before parking – heh!

I don’t sit with my car parked up and engine running though – would this not just make it hotter? I’ve noticed my fan has came on the last couple of days when I park up anyway, is this just because of the change in weather or something? The temperature gauge sits as always on 90 and never moves.

I’m sure this sort of discussion has been raised many a time before but I couldn’t find anything on the search results. Advise would be appreciated.

Cheers fellas! /ubbthreads/images/graemlins/beerchug.gif

 

[recomdos]

cool - thanx mark

 

[jetspeed]

what he had was called a turbo timer, it keeps your engine running after you take the key out for as long as you set it for. I used to have one on my eclipse gs-t and had it set for 2 minutes. I would get crazy looks from people when I got out of my car and locked the door and it was still running, a lot of times people would even come up to me and say "hey your car is still running" /ubbthreads/images/graemlins/lol.gif

 

[recomdos]

[ QUOTE ]
JetSpeed said:
what he had was called a turbo timer, it keeps your engine running after you take the key out for as long as you set it for. I used to have one on my eclipse gs-t and had it set for 2 minutes. I would get crazy looks from people when I got out of my car and locked the door and it was still running, a lot of times people would even come up to me and say "hey your car is still running" /ubbthreads/images/graemlins/lol.gif

[/ QUOTE ]

yeah - that's it!!!!!!!! that's what it's called! a turbo timer! I must admit when he switched off, i didn't hear it still running? /ubbthreads/images/graemlins/confused.gif maybe I wasn't paying enough attention, and too busy checking no bits had fallen off me due to g-force! heh it's so low down too!

But that's all it is, just a power toy, no luxury like the audi! plus at 20mpg it wouldn't be practical for me! lol

i think thsi turbo timer thingy sits on his dash and shows what boost he's getting too - would this be right?

fanx!

p.s. jetspeed I had a mate from Portland Oregon staying with me for a few months last year. ain't been in touch for a while, but he's over here studying. I do plan to visit him sometime - wot's portland like?

 

[jetspeed]

recomdos, yea the turbo timer is just a little box that you can mount anywhere really, right on the dash is a popular place though and yes they can be a boost controller as well, if you get the fancy expensive nice ones. Portland is awsome, I love it here in the Northwest and would rather live here than any other place in the US, definately come visit, you will love it.

 

[StephenBogan]

My mates got one in his Scooby. He's shown me how it works, it measures what boost you've been running for how long and from this gauges how long to leave the car running for. Nifty bit of kit.

I've always just let it run at idle for a minute or so if I've been kicking it a bit but if its to the extent that it glowing, I'll take it a run nice and slow till it cools rights down. Paranoia! Paranoia! That me, and myself! (but better safe than skint!)

 

[StephenBogan]

down the back of the engine mate, as Rich said, give it enough stick and it looks like a UFO landed under your bonnet!

 

[excursion]

It's always best to let the car idle after a hard run. The problem starts when the engine is shut off, the oil has stopped circulating through the turbo and the residue becomes superheated, and turns to carbon on the turbine shaft.

You can imagine what happens over time - coked bearings and unbalanced turbo. After-cooling can go some way to alleviating the problem but can never stop it - the oil is stationary in the bearing section.

boobies

 

[audidude]

There is no need to "cool down" the turbo on Audis - coolant still circulates after shut down.

Turbo timers are needed in less advanced engines and by those who enjoy the overt trappings of the turbo culture - you know - the flaunted boost gauges etc - goes with the reversed baseball cap /ubbthreads/images/graemlins/laugh_roll.gif

Cheers

 

[excursion]

That’s not exactly true mate, the water is there primarily to get the turbo up to temperature quicker and maintain a constant temperature during spirited driving. Aftercooling is a secondary benefit, but it’s no substitute for driving off-boost for a few miles or letting the car idle – the small amount of water that goes through the turbo cannot possibly cool that large mass of red hot metal quick enough to prevent carbonization of the oil.

Here’s a bit more info on it:
Audi turbo

 

[paulbinks]

The coolant pump runs for 5 mins or so after turning off the engine on my S3 but the turbo could still be rotating at 100,000 rpm with no pressure on the oil lubrication side which causes premature bearing/shaft wear etc, also how do you know you were driving off boost if you have not got a boost gauge fitted,try one you will be suprised to find out when it is on boost even when driving like a christian do-gooder.
Cheers " Bingo "
/ubbthreads/images/graemlins/beerchug.gif

 

[Ess_Three]

[ QUOTE ]
bingo said:
The coolant pump runs for 5 mins or so after turning off the engine on my S3 but the turbo could still be rotating at 100,000 rpm with no pressure on the oil lubrication side which causes premature bearing/shaft wear etc,

[/ QUOTE ]

Are you suggesting that the turbo could still be spinning at 100,000 RPM after the engine is switched off?

 

[recomdos]

[ QUOTE ]
ScotSTHREE said:
down the back of the engine mate, as Rich said, give it enough stick and it looks like a UFO landed under your bonnet!

[/ QUOTE ]


hee hee! lol as for all the other comments guys, I think I'll continue to just drive out of boost for the last few miles of my journey (I sound stoopid here, but that's as long as I'm under 3k rpm correct?, I ask because of the talk of all these turbo timers etc etc /ubbthreads/images/graemlins/confused.gif)

 

[mramage]

It's not really a question of revs, it's using a light throttle. You can still heavily be on boost at 2-3K.

Just be gentle with it. Stop and watch the turbo cool down after you've been driving hard at night. You'll see it takes a few minutes before it stops glowing red. Similarly, you could drive under 3K on full throttle from lights to lights and still end up with a glowing turbo.

Drive it like it was cold, lowish revs, as little boost as you can. Obviously if you've been thrashing it seriously it's worth a general cool down all round.

Lets put it this way. Coming off the motorway for services I drive at 70 or less for the mile before the services. I then stop for about 2-3 minutes before shutting off. Coming home I have 1.5 miles of 30 before my house. I take it easy, gently park and just give it a few (5) seconds before switching off.

Just apply some common sense and remember, this is just my opinion. If my turbo packs up tomorrow I might revise it /ubbthreads/images/graemlins/smile.gif
/ubbthreads/images/graemlins/beerchug.gif /ubbthreads/images/graemlins/beerchug.gif /ubbthreads/images/graemlins/beerchug.gif

 

[recomdos]

[ QUOTE ]
Mark R said:

Just apply some common sense and remember, this is just my opinion. If my turbo packs up tomorrow I might revise it /ubbthreads/images/graemlins/smile.gif
/ubbthreads/images/graemlins/beerchug.gif /ubbthreads/images/graemlins/beerchug.gif /ubbthreads/images/graemlins/beerchug.gif

[/ QUOTE ]

hee hee - I say the same sort of stuff! lol yep, I think I get the jist, can't understand how the car is in boost if less than 3k? /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/confused.gif me being blonde!

 

[mramage]

[ QUOTE ]
recomdos said:
hee hee - I say the same sort of stuff! lol yep, I think I get the jist, can't understand how the car is in boost if less than 3k? /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/confused.gif me being blonde!

[/ QUOTE ]

You're car is chipped from AMD, yes? You should have a printout, note how high the torque is low down /ubbthreads/images/graemlins/smile.gif Mucho boost! You defintely should be feeling some hefty pull by about 2.5K in a chipped 1.8T Should hear it also.

Honest, it's well into boost before 3K /ubbthreads/images/graemlins/angel.gif /ubbthreads/images/graemlins/beerchug.gif

 

[recomdos]

[ QUOTE ]

You're car is chipped from AMD, yes? You should have a printout, note how high the torque is low down /ubbthreads/images/graemlins/smile.gif Mucho boost! You defintely should be feeling some hefty pull by about 2.5K in a chipped 1.8T Should hear it also.

Honest, it's well into boost before 3K


[/ QUOTE ]

yeah - it is chipped from AmD, I'll have a looksy at the dyno chart thingys and see what they say. I didn't realise this would change boost etc /ubbthreads/images/graemlins/frown.gif just aswell I'm pretty carefult and concious about it all anyway eh? so with it being chipped should I take any other precautions?

 

[excursion]

LOL. yes it is easy /ubbthreads/images/graemlins/smile.gif