Many of us have done this and wondered Does Denting Headers Rob Power?
Lets find out in the video below.
I came across this test recently showing on YouTube and thought this would appeal to a lot of people who like me have fitted headers either when overhauling, modifying or fitting a different engine, and is often the case some ‘butchery’ is required to give the header/s clearance from obstacles such as starter motor or perhaps a steering box or shaft.
Then we wonder how much our mods have actually affected the power output of the engine. To find out several tests are done on a Dyno and I must say results weren’t what I was expecting.
Especially when you consider these guys were absolutely butchering the header pipes instead of heating and then gently squeezing the pipe just enough to gain the clearance required.
This way the overall circumference is maintained without obstructing the exhaust gas flow too much.
But no, before each test they just bashed it some more to see what power and torque loss would record on the Dyna without considering what the header would look like. If done like this in a vehicle it would be a case of “don’t open the hood!”
How much was the power loss? Well you will need to view this video to find out the results because to be fair you do need to watch it , and perhaps like me wonder what the results would be if this was done to a header with tighter radius curves. I guess a lot would depend on where you need to alter the pipe.
Tested on a 560HP warmed up engine, these headers were truly given a beating, especially on the last test. Find out much HP and Torque was lost.
A special thanks to Motor Trend Channel for this video. Screen shots are from the video.