Can someone help me understand the importance of backpressue?

[Rafs-T-Type]

Why couldn't you run your car with no headers at all? assuming a NA car . It just seems like the less restrictions the better it should move.

 

[earlbrown]

I cringe every time I see the word 'backpressure'.


If you run a cam that's why too damn big with too much overlap, corking up the exhaust will get you back a little of the power you lost from over-scavenging. The better of the scenarios is to run a correctly sized cam with as little flow restriction as possible. That way the scavenging effect you get from a set of headers can actually help instead of just letting raw air/fuel run out the exhaust pipe. That doesn't apply turbo engines.

On a turbo car the exhaust manifolds are pressurized so you can't make a low pressure pulse at the exhaust valve. Same negativity comes from too much overlap on our engines though. We don't need an exhaust snatch during over lap to pull air/fuel across the combustion chamber, we've got boost to do that job. Too much overlap just blows it right out the cylinder.

 

[TurboBuRick]

You get that Raf?

 

[DR BOOST]

Why couldn't you run your car with no headers at all? assuming a NA car . It just seems like the less restrictions the better it should move.

most people would prefer not to melt their inner fenders and raise their under hood temps 1000 deg.