Manifold shroud to filter pipe
Manifold shroud to filter pipe
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Discussion

SamHH

Original Poster:

5,063 posts

233 months

Sunday 26th November 2006
quotequote all
In my car there is a shroud that covers the exhaust manifold. There is a pipe that connects this shroud to the air filter. What purpose does this serve? Don't you want the air going into the filter (and eventually the engine) to be cold not hot?

GreenV8S

30,956 posts

301 months

Sunday 26th November 2006
quotequote all
In very cold weather, engines tend to be more tractible if they're fed warm air. It helps the fuel evaporate better and reduces puddling and all the transient problems that come with that. Warm air reduces the peak power, but most people are more interested in having an engine run smoothly and reliably. Engines with air heaters on the exhaust would normally have a manual flap with 'summer' and 'winter' settings, or a thermostatically controlled flap, to bypass the air warmer in hot weather.

SamHH

Original Poster:

5,063 posts

233 months

Sunday 26th November 2006
quotequote all
Thanks for the explanation.