Headers N stuff

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Frank Enstein

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There isn't a "Best setup for Everything". There are many other factors that flavor the outcome.

As an example, I made a stepped, equal length, 4-2-1 header for my Yamaha 1100. It worked really well but at high rpm it over-scavenged, lost power and went rich. If I reduced the overlap by retarding the intake cam it would have worked even better. As a quick fix (no time or money) I put a more restrictive muffler on that dampened the over-scavenging at high rpm.

If you have more exhaust duration on your cam than the engine wants and/or really good exhaust ports in the head(s) true duals will not show much gain from a balance/merge pipe in the exhaust.

This it commonly overlooked by enthusiasts and racers alike. An X pipe on my Firebird gained 40 horsepower over true duals with the same mufflers and tailpipes. Pontiac heads have pretty weak exhaust ports compared with an SBC, BBC, or LSX.
On a comparable BBC the gains would likely be half that due to the engine pumping out the heads more easily in the first place.

Where people get misguided is what works on one combo may not work on one that is a bit different.

The common denominator is you need to tune the entire package to see the most gains.

Car magazines would put an open carb spacer on an engine and gain 23 horsepower but there was no mention of tuning!
Did the engine run better from the increased plenum volume/larger radius for the fuel to make the turn into the runner or did it gain because the engine was too rich and the spacer leaned it out.

The bottom line is choose what you want for exhaust and tune it until you're happy with how it runs.

BTW the Firebird gained 80 HP tuning the carburetor. The carb ran fine out of the box but careful, methodical tuning brought out it's true potential.
 

Supercharged111

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Shorties gain no power as I’ve seen (at a track) on a few cars. Any HP “gained” on a 3300lb car will be even less noticeable on a 4-5,000lb truck

Hedman makes an “Elite” series and I haven’t installed a set yet but there isn’t anything on the market that comes close to them in heavy duty construction. 14 gauge tubes and 3/8” flanges should provide a pretty reliable header (in a long tube and ceramic coated).

I’ll be installing the Hedman Elite on my project.

My 1500 has Hedman Elites on that I bought back in 07 or 08. Just be sure to weld the outlet flange to the header or you'll be constantly retorquing.

They did this with a 360 (?) hp LS . They ran duals, duals with an H pipe and duals with an X pipe. The difference was not worth the time. They came out with something like 2 HP and 2 Lb Ft of torqe difference across all three.

The one I saw may have been a small block, but the difference was more like 7-8 ft/lb between divorced/H/X/Y. X is still worth it for the sound, made a huge difference on my Z06 for sound. That coincided with longtubes and a 3" midpipe, so overall the car picked up substantially from an idle to redline as well as the shriek it now has up top.
 
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