If thats true, then all the NMRA guys would be running tailpipes, but they're not. Pure Street and Factory stock run tailpipes, but thats because its a rule.
Let me restate that. At my current horsepower (260-270) and exhaust with dumps (3") is not restrictive enough and results in a loss of back pressure. Horsepower increases but torque decreases. To solve this I could add more power to utilize the exhaust size that I have or make the exhaust more restrictive (such as tailpipes) to match my power. So in my situation restricting my exhaust may actually give me a better ET due to increased backpressure to equal more torque. I do agree if they allowed Prue Street to run dumps they would most likely go fasted because they could actually benefit from a less restrictive exhaust. All depends on your combo (I should have said that in the first place).