Ceramic coating of downpipe

[Tfsi_Mike]

2p worth? ^^^ ??? about 14 quids worth there 

[alackofspeed]

2p worth? ^^^ ??? about 14 quids worth there 

Bite me! 

[craigy123]

What have I started..........? 

[Tfsi_Mike]

2p worth? ^^^ ??? about 14 quids worth there 

Bite me! 

 

What have I started..........? 

War !!

[alackofspeed]

What have I started..........? 

A distraction from the pain of trying to find a replacement engine for one I killed on Sunday..... so thanks for that!

[alackofspeed]

What would pour faster, cold custard or hot custard?  

[pendantic barstewards mode  ]

bad choice - custard is a non Newtonian fluid, like ketchup and blood, and simple fluid dynamics equations don't define their behavior.

Hot custard does pour faster however....

[/pedantic barstewards mode]

 Quite fancy some custard and cake come to think of it .

[the bruce]

Awaiting Bruce's reply 

I already thought it's pointless, but I hope 'alackofspeed' has made things clearer:

If you've got a high velocity fluid you have a high pressure drop per metre of pipe, if you have a high temperature fluid you have a higher molar volume which dictates a higher velocity flow. Post turbo, temperature is bad, high velocity is bad, high back pressure is bad.

It's not quite as simple as the ideal gas law, as there are simultaneous elements to calculations governing exhaust gas flow, but very crudely... double the temp, double the volume. Double the volume, double the velocity (for a given molar flow). Double the velocity, quadruple the pressure drop.

My 2 p worth.

 

What would pour faster, cold custard or hot custard? 

bad choice - custard is a non Newtonian fluid, like ketchup and blood, and simple fluid dynamics equations don't define their behavior.

Hot custard does pour faster however....

again: 

Nice example, but different thing though, Alex.  Custard changes viscosity, gases mainly change volume with temperature.

[vRS Carl]

[94Luke]

I am utterly confused. Have you got a link to a web page or book explaining/backing up what you're saying Bruce?

[the bruce]

You won't be able to read most of my books.  (they aren't english of course)

Thought everbody here agrees that gases expand when they get hot.
Think of your tyres when you drive fast. Tyre pressure will increase.

I guess that's the point. 


Of course both larger diameter and smoothening sharp edges will improve flow.
I never would say anything against that.

[vRSAlex]

So what you are saying is that the pressure of the exhaust gases increases as does the volume?

With a tyre, there is no where for the gases to escape to so its going to gain pressure in a different way to an exhaust with an open end.  So surely the higher pressure will force the exhaust gases out faster?

[Tfsi_Mike]

Day 3 of the exhaust wrapping saga 

[RobH]

I never thought id see a willy waving thread in physics, my formulas bigger than your formular

[Poverty]

All this for a 2.0tfsi lol.

[Tfsi_Mike]

All this for a 2.0tfsi lol.

The engine the forum is based on....