Re: exhaust wrap

["Jim Adney" <jadney@vwtype3.org>]

> Also, why would a Turbo engine require header wrap, and not a normally
> aspirated?

To keep it simple, the turbo is there to extract power from the 
exhaust; it uses this power to compress the intake air.  Part of that 
power is stored in the form of heat in the exhaust, so the warmer the 
exhaust the more power the turbo will be able to extract from it.

I'm sure the actual thermodynamics are much more complicated, but the 
end result is the same.

In a normally aspirated engine all the power in the exhaust is going 
to be wasted anyway, so no one really cares HOW you waste it.  Of 
course wasting it in such a way that it makes the engine overheat 
would be be counterproductive.

Jim
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Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
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