did you remove any 02 sensors b/c that would f**k up your a/f ratio and make your car run like ____. ( that could be wrong so don't take my word for it)

 

Yeah your ECU would be getting some F'ed up readings and your performance would suffer. Older cars didn't have all these sensors and an ECU controlling fuel injection and A/F ratios, that's why they would benefit by removing the restriction but on modern cars it's not that simple.

 

Wow..

 

back pressure is bad. exhaust velocity is whats imporant because the gasses moving down the header and thru the exhausr pipe are supposed to create a vacuum in the header pipe, which helps draw out from the cylinder the exhaust from the next combustion.
thats just what I heard

 

Turbos love next to zero back pressure - ie Straight single fat piped exhaust, NA and SC need the backpressure for some reason.

Don't take my word
This is just what I've heard.

 

When you drop the backpressure in large amounts, you are affecting many operating parameters. The amount varies with system design. You are greatly affecting the amount of air into the system, meaning your ECU needs to provide more fuel to keep the proper air/fuel ratio. This can also affect the operation of the EGR valve in some situations. This being said, if the drop in pressure is more than the system is designed to handle, it can degrade performance. Idealy, super low backpressure is great, if the rest of the system can handle it. So basically, it DOES affect performance. The degree to which it does (in a negative fashion) depends on the rest of the system. I know, this does not clearly answer all the questions as to when it is good and bad, as it depends on the engine and engine control system design.

Also, when you consider exhaust gas velocity, a good design provides the highest velocity with the least constriction. A system with a huge exhaust has very low restriction, but very low velocity. A system with to small of an exhaust provides the exact opposite. As we can see, there are many many factors to consider... which is best left to the intake/exhaust gurus to calculate exactly

 

lol...it was for fun and i did it for about 10 minutes its fun to try new things. And NO running open header will not mess up anything.

 

open header=loss of torque more top end

 

basically he did lose power, by removing the exhaust after the header he shortened the exhaust, therefore moving the "usable" powerband up a few thousand RPM's basically to a point higher than the stock intake manifold, cams, and ecu will ever let that motor see, so for a basically stock street motor the power is lost, the whole thing is not about back pressure per say, but about making power in a usable RPM range, somebody slap me , Im babling again, by the way I would like to introduce myself , Hi all, as you can probably tell from the screenname, I am somewhat of a header designer/fabricator/guru, pretty competant with intake manifolds as well but I can go on and on about myself lol, no really