If I read that chart right, about 40+ HP and 40+ lbs Torque at around 4500 RPM with the 265's over the 315's. And that advantage is noticeable through 5200, then the 315s play a bit of catch up, but still are down a bit. I would assume thats just airflow but would love to see that if you would have had a hat on it when testing. The other thing that would be interesting to know is air/fuel distribution per cylinder, that would have required separate sensors on each cyl. Just to see why the 265's are out performing the 315's on this engine even at higher RPMs. Was that just more air, or better more even distribution?Did you see the graph at the end of the video. That was optiona 2 vs 3. Option 1 was slightly lower than 2 but didn't tha e open headers. I only did mid pipe testing to see what the car config numbers looked like.
Also interesting, would be that the 265's dont fall off as hard at 6800? I am curious what the possible thoughts are there.
Anyway, Thanks for sharing. I love this kind of Dyno testing.