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Supercharger - Cooling Down
ash_hammond - 7/12/09 at 10:08 AM

Is it as important to let a supercharged engine cool down after a long run as you would if the engine was turbocharged.

-Ash

Mr Whippy - 7/12/09 at 10:20 AM

no, the turbine components do not get very hot and no where near turbo temps

stevec - 7/12/09 at 10:32 AM

If its a Rotrex it may be wise to idle the engine for a minute before switching off to allow the oil/traction fluid circulate and cool a little as the fluid is not rated at a very high temp.
Steve

ash_hammond - 7/12/09 at 11:04 AM

quote:
Originally posted by Mr Whippy
no, the turbine components do not get very hot and no where near turbo temps


Thats what i thought.

Its Cooper S....

A1 - 7/12/09 at 12:52 PM

id say yes too, just to let the oil circulate and cool a touch

flibble - 7/12/09 at 01:03 PM

If it's an eaton type then I'd say it makes no difference, not sure on centrifugals.

cd.thomson - 7/12/09 at 01:09 PM

it would appear you should do whatever you like

yes the cooper supercharger is eaton m45 I think

Project7 - 7/12/09 at 02:52 PM

Isnt letting the turbocharged engines idle for a while before switching off, to give the turbo time to stop spinning and prevent the lose of engine oil pressure mullering the turbo bearings?

With a supercharger the engine stops turning, and so does the supercharger.

MikeRJ - 7/12/09 at 06:08 PM

quote:
Originally posted by Project7
Isnt letting the turbocharged engines idle for a while before switching off, to give the turbo time to stop spinning and prevent the lose of engine oil pressure mullering the turbo bearings?


The idea is to let the flow of oil and coolant around the turbo cool it down. If you suddenly stop the flow of oil to a red hot turbo, the oil remaining within the turbo gets cooked and turns into carbon.

The turbo will spin down to sensible speeds very quickly (seconds) but it take take a lot longer to get it cool enough to safely switch the engine off if it's very hot. The easy way out of this is not to thrash it for the last few miles of your journey...

deezee - 7/12/09 at 07:16 PM

You don't leave a turbo diesel engine running for a minute at the end of your journey do you? That doesn't seize all the time.

Most turbo chargers are also liquid cooled to remove this very problem. I.E. the engine coolant soaks up any heat, not the turbo. As a supercharger isn't using exhaust gas at hundreds of degrees, its going to be fine.

ash_hammond - 7/12/09 at 07:37 PM

Thanks Guys,

I thought i new the correctish answers, was just checking i had not missed an important point.

-- Ash