Engine Masters - X vs H vs Straight Exhaust

Well put mat, I believe that's exactly what they were going for. Kinda like doing a dyno run with a k&n filter or regular paper filter, just a good premise on what should happen when swapping one for the other

I wonder if they would have tried to dial
In the carb and timing with each change what the outcome would be

I'm sure that would show right up on the AFR gauge if they used one.

My only guess is, a bit similar to the dented header test, what if the two seperate exhaust tubes were already big enough for the engine in the first place?
No real improvement would be expected whatever the crossover would be.

I'm thinking maybe some benefit would become visible if the exhaust was on the small side to begin with, and combining both pipes with and H or X could show more beneficial.

I haven't watched the video, but peak numbers are not the important factor in most applications. It's the "area under the curve" that affects acceleration. Even if a combo is down on "peak" HP and/or torque by a sizable amount, it can be out-accelerated by one with less peak but a "fatter" curve. Also, a few HP through the range may not sound like much, but it does add up.

I tested X-pipes & Dynomax mufflers on my car 10+ years ago and it was beneficial, even before I took the 60+ lbs of weight out from elsewhere in the car to bring it back down to "race" weight.. I forgot the numbers, but they were good enough to where I kept it on the car despite the pain of having to drop the exhaust on the rare occasions I had to pull the engine or trans. But it does only involve the 6 collector bolts and 2 hanger nuts towards the back. I had Dynomax UltraFlo mufflers at the rear end but went to their "bullet" style for more clearance around the center section with no obvious performance difference. It's all TTI stuff, including their 1 5/8"-1 3/4" step headers.

I kinda like the quieter tone & I hear more of what's going on. But it did scare me initially because I heard noises I never heard before over open headers. I get lots of compliments too. The X-pipes & mufflers are also on my 360 Aspen wagon for NHRA. I just have to get it back together after getting water in the engine.

As many have said, each combo is different and your results may vary. Just gotta try it. But reading & listening to a variety of sources, opinions & results can help you make an "educated" decision.

Almost forgot.....After having dialed in the carb over the years, my particular combo did want a little less jet after the exhaust was installed, which I figured out later.

The whole point that everyone is missing is that X pipes drop ~3dB. X-pipes make more power because you can use a free-er flowing muffler that would otherwise be twice as loud. Also the formulas for best H vs X pipe placement are different. Once the ideal collector length is established, the H pipe goes halfway down the ideal collector. (even open collectors benefit from this) X-pipes go where the end of the ideal collector is. Throwing a couple band or V clamps pre and post the X completely gets rid of the "oh no my transmission is trapped problems. If you want to sound like a blatty Harley, straight pipes are for you.

It's like lookin for power with oil weight. Stupid.

My Dart goes on the dyno this monday.
Now with 2.5" exhaust X-pipe and Borla's.
But too much has changed since the last dyno session to give any sane comparison.

It's not logical that a 6 inch connection could make any power and the video
indicates no meaningful difference.
I would think above idle there would be no flow at all between sides and there very well may be some interference.
In either situation the exhaust can't get out any quicker.