hey guys, i have a Q about the K20 or K24 builds that builders do. I see a lot of builders running the short exhaust out of the Hood, pretty much a long tube header, or running a side dump front fender even on NA cars./
Doesn't the engine need a exhaust to create backpressure? im talking about exhaust like these

 

No, it does not require it. Stock to moderately built engines utilize some exhaust "scavenging" to increase mid-range torque as well as maximize light throttle and idle conditions.