Roe S/C with Belanger headers VS B&B headers: Graph inside

[Marv S]

Tri-Y headers have been around for a long time.

They were used on small blocks and less on big blocks.

The pitch was the same then as it is now - tri-y had smaller tubes and gave the benefit of increasing low end power - a good thing for the small block.

The merge collector exhausts used larger tubes and had higher flow rates. Result was more power at the top end with a lot of air moving but a bit less power in the mid range than a smaller tube tri-y.

You might conclude that for stock Viper with those small block holes that a tri-y has a benefit in the mid over a merge. But that the merge will flow more air at the high rpm use or forced air conditions.

[Mr Hemi Head]

It appears that B&B make a 5 into 1 and Tri Y, which ones gave the performance boost?

[DSR207]

It's gone for no reason...Here it is again David Weaver's before and after dyno graph

[KenH]

I guess the one thing that doesn't seem to add up to me is why there would be a relatively even gain across the whole RPM range. If the header is a restriction at the higher flow rates, you would expect to see near equal performance at lower RPMs and then the higher flowing header would pull away from the lower flowing header when it started to become a restriction somewhere in the higher RPM range.

Makes me wonder if there isn't some other factor at play.