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warm up/cool down times

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Old Dec 19, 2003 | 06:09 PM
  #1  
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pippyrips
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From: Bebind the wheel of my red rice rocket
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How long do you give your scooby when warming up before playing? similarly how long do you let it idle for before switching the engine off?

cheers

P.S.

The reason for warming up is obvious but why the cool down??
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Old Dec 19, 2003 | 06:12 PM
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From: In the sport section...
Talking

i usually wait untill the water temp is up before gunning it.

depending how far i've been depends how long i leave it idling, but i always leave it for at least 30 seconds, even if i've just nipped to the shops


gav..
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Old Dec 19, 2003 | 06:15 PM
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From: Lancs
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As far as i understand it, the Turbo operates at very high temps, because of the speeds it gets up to. So when you switch the engine off, the oil pumping around the Turbo stops moving and therefore cant do its job of cooling, so the oil that is in contact with the turbo can get "cooked" for want of a better word, and then turns into some sort of slush and muck, which has you can imagine cant be very good.
I might be shot down in flames but thats how i understand it
Of course i suppose it only applies if the Turbo has had a lot of use before you switch off
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Old Dec 19, 2003 | 06:30 PM
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From: SMACS member,Resident valeter/pc installer
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I drive away straight away after starting and only use the turbo after 10mins.This is to let the oil come up to temp.
After coming to a stop, I always idle for 1 minute.
I try to drive gently for the last mile or so also.

Hope this is useful

*****
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Old Dec 19, 2003 | 06:59 PM
  #5  
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Can only second *****'s advice
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Old Dec 19, 2003 | 07:07 PM
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From: LIVERPOOL THE CENTRE OF EXCELLENCE
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Just remember, it doesnt matter how long you leave it ticking over for. The important thing is you MUST rev it to 7 grand then turn it off.

If you listen closely you can hear the turbo spinning for a least 30 seconds.......with no oil feed. They love that.
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Old Dec 19, 2003 | 07:07 PM
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Third tabs on *****,
I just take it easy for last couple then sit for 1 min before cutting off
the engine,
Just feels like i'm looking after her!!!
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Old Dec 19, 2003 | 08:20 PM
  #8  
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From: Lancs
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Found this on `Motorsport Developments` website look at some of the figures




The average temperature of the exhaust gas, at the entry point to a diesel turbo, is 800 degrees centigrade. A petrol engine can reach 1000 degrees, glowing bright yellow. Hot enough to melt window glass.
New generation turbo's impellers rotate at up to 220,000 revs per minute. The impellers on a Boeing 747 engine rotate at about 7,000 revs in comparison.
The air entering a turbo's compressor impeller can be travelling at a speed close to mach 1.
At average engine revs, a medium size turbo will swallow 130 cubic feet of air per minute, equivalent to the interior volume of a transit van.
Turbo shaft balance is crucial - imbalance at maximum revs equivalent to a 2 kilogram force is acceptable. We often finds turbos supplied for service with 6 kilos of imbalance. This is equivalent to driving along with a brick attached to your wheel rim.
The "hot end" turbine blades in a turbo, are made from a high nickel content alloy, as used in jet aircraft engines. A blade will travel in the region of 820 mph at average engine speed, and the exhaust gas entering it will be supersonic.
A turbo will accelerate from 20,000 revs per minute to over 150,000 revs per minute in less that one second.


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Old Dec 19, 2003 | 08:34 PM
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From: Bebind the wheel of my red rice rocket
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nice one guys
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Old Dec 19, 2003 | 10:17 PM
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From: the middle bit
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wood add water temp is not sumin i'd wana wait to till i booted it redlining just kuz the water is hot is bad as oil will not necessarily be sufficiently hot
But yeah dont rape it from word go & within a minute of shut down & generally all good as a rul IMO
Si
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Old Dec 19, 2003 | 10:18 PM
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From: the middle bit
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thats drunk talk for oil takes longer than water to warm up
Si
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Old Dec 19, 2003 | 10:30 PM
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From: Aberdeen
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Agree with si

When my water temp has just reached operating temp, my oil temp doesn't reach normal(85-95C) until about another 5-8 mins.
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Old Dec 19, 2003 | 10:39 PM
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From: From the land of dings and dents
Thumbs up

Just remember, it doesnt matter how long you leave it ticking over for. The important thing is you MUST rev it to 7 grand then turn it off.
PMSL


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Old Dec 19, 2003 | 11:19 PM
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From: the middle bit
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works on a rotary lmfao
Si
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