Benefits of mass production. A person would spend a lot of time trying to build those and they wouldn't come out as nice.

The collector does need to be a bit longer to work right. I think PipeMax will tell you to put a 15 inch collector on it or something like that.

One nice thing about the Schoenfeld headers is that they have the long straight section before the collector so you can cut the primary tube length down if you want to. If you want to run a merge collector then you have the room to cut 10 inches or so off the primaries and weld in a merge setup.

+1 on the collector length; I was going to suggest 18" as a baseline.

The collector design used looks low tech, IMO. Merge or not, you might want to see what options you have to cut those off and replace them with a more efficient design (unless there's more hiding inside than the outside leads me to believe).

That is good feedback. Eventually I'll have more time to revamp my other set and maybe spruce up this pair.

I'm not really looking for some righteous hp number just trying to get a baseline on the engine + nitrous and detect any leaks, squeaks, etc. before it goes in the car. That said if I was trying to sell parts/engines and/or competitively racing I'd be more motivated to try some exhaust header variables.

This stuff is just a side hobby for me so I'm just excited to get my new combo running in the car after four years. Our local track is 45 minutes of back country roads from my house so I'm driving it there on a DOT tire, making some passes, maybe catch dinner and a movie and then putt home.

Maybe if we get serious with the Tunnel Ram/Lenco combo in the black car I'll try some of the stuff mentioned above. I am starting to consider getting an Indy low deck block however the cost seems obscene to me.

I have said for the longest time that the collector length need to
be added on.. in MOST cases it should end up in the 16" to 18" range
but other factors come into play... and a big one is RPM.... I use
to love building headers.. I think I am just over a 100+ sets.. about
14 sets for my own junk... plus doing a lot of 2 cycle chambers.. I
learned a lot of merge stuff working on chambers

Interesting notes Mr. P!

For conversation let's say I am going to run a full 3" TTI exhaust system. Would I want to cut back the 3" pipe on the head pipes and add in, for example, an 18" length of 3.5" to the collector? Is this an open header only thing?

For instance the dyno has 4" flexible exhaust tubing that goes to giant roof mounted mufflers.

Would the results improve if the exhaust was unhooked from the dyno room exhaust system? Obviously this is impractical - anybody want to weigh in on the theory aspect of it?


Also of note: I mocked up a standard Mr. Gasket header gasket to the Schoenfeld headers and the ports will need some clean up to match the gasket. Not a big deal because the surfaced them and then ground away the weld bead therefore some clean up with a carbide burr will be necessary.