X pipe H pipe or side by side
I see what you're saying and can't make an argument against it because I don't have the time, money and resources to do all the testing you have apparently done. With that said can we not assume that most guys on here are hobby guys like me and lack the resources to completely science out the headers on their cars like you have done? I can say this however, every car I've had with a full exhaust gained torque and sounded better when I added an H pipe. The cost was minimal and all it took was a few hours of work. Maybe it is a crutch but its a nice inexpensive one that works good.
Did you actually DYNO your stuff? If not, you can't say what happened.
I always relate this story. I had a customer come in and want an engine. I told him to bring it what he had, so I could get it on the pump to see what he truly had for HP (and as per normal, he mas 150 less that he thought as he had an HONEST 350 and not 500).
We made wholesale changes to his program, made him correct his gearing and buy new headers. When done, we found about 75 HONEST horsepower. And he promised me he was a chassis tuning wizard.
At the track his car was S-L-O-W. After 3 weeks of pissing and moaning I decided to go out and see what the issue was. He couldn't tune a fish. I wasn't any help, be cause I'm a drag race guy. He blew the tires off every time he touched the throttle. Since he couldn't fix his car, I took 86 degrees total timing out and made the throttle open only about 75%. Then he set his fastest lap times every.
There is more to testing and tuning than time slips. Sometimes, killing horsepower is faster. And without actual data, you have no real idea if you made HP, lost HP, moved the torque curve up (making the same RPM effectively less powerful), moved the torque curve down (same as killing HP).
I'm not criticizing you. Just saying without data, you have no idea what happened, except the car was quieter and went faster.
I hope you understand this.
