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Header wrap

Posted: Mon Jan 19, 2009 2:57 pm
by misfit4life
Does wrapping your header give you any gains or is it just a bunch of BS

Posted: Mon Jan 19, 2009 3:09 pm
by racer12306
Very minimal really. The issue on a street car is it getting wet. Could get moldy and nasty quick.

Posted: Mon Jan 19, 2009 6:05 pm
by acrclonetrooper
all it is really going to do it keep the heat down around the pipes....but like stated above. any difference would be minimal.

Posted: Mon Jan 19, 2009 9:08 pm
by JaxMadine
Its good for making the header rust out prematurely. You wrap what you want to protect from heat, not what causes the heat.

Posted: Wed Jan 21, 2009 10:37 pm
by DOHCRT
The purpose of header wrap is to keep the heat inside of the header. This, in turn, helps to maintain exhaust gas velocity and improves exhaust scavenging.

This is the same reason why stainless steal is the best material for header construction. Stainless steel does not transfer heat as well as mild steel, therefore more of the heat stays in the exhaust gas.

Heat is energy (power). Anytime you have heat radiating away from anything, you are loosing power.

Posted: Wed Jan 21, 2009 10:56 pm
by racer12306
^^^yes, but on a street car its a waste

and can cause problems.

Posted: Thu Jan 22, 2009 1:55 pm
by DOHCRT
racer12306 wrote:^^^yes, but on a street car its a waste

and can cause problems.
Why exactly is it a waste? Just because the car is driven on the street doesn't mean the principles of thermodynamics do not apply. If you're trying to achieve maximum output from an N/A engine, every little bit helps. If you're just looking for a few extra ponies from bolt-ons, look elsewhere.

Its only a waste if you wrap a shitty header. Header wrap or ceramic coating isn't going to make a poorly designed header perform better. That being said, you shouldn't waste your money on a header that is poorly designed. Conversely, if you have a nice long tube header, you will benefit from wrapping it. Get a header with a good merge collector and you will see a lot more power gains. Why do merge collectors work so much better than dump collectors? Because they promote much higher exhaust velocity.

Wrapping a header only causes problems if you live in the rust belt. Mild steel headers don't last too long in these climates anyways. Not everyone with a street car has to drive through snow covered salt every winter. If you do live in an area where rust is a problem, stainless steel is the way to go.

If I had an N/A engine, I would definitely use a stainless header with no wrap because I live in the rust belt. If I lived in a place like Arizona, however, I would wrap the header.