Length of header primaries
 

How much can they vary within the same set without some negative effect on power? 2 inches , 4???

Re: Length of header primaries
 

http://speedtalk.com/forum/viewtopic...42375&start=15

http://www.exhausting101.com/?p=37
http://www.speedtalk.com/forum/viewtopic.php?t=41836

Check these out & look into Calvin Elston.
He blows away some myths about Exhaust systems.

Re: Length of header primaries
 

Larry Meaux, the guy who does PipeMax software, is another good source.

Re: Length of header primaries
 

Thanks guys...Adger , lots of intense reading there...LOL
Alan I have a copy of PipeMax also...I'll take another look. When he gives you a "range" of lengths that fit the harmonic order , then I can only assume that as long as you're in that range , even if there's length variation....you're good to fly.

Re: Length of header primaries
 

Some guys even run unequal length on purpose.....

See you at the races,
Wayne Kerr

Re: Length of header primaries
 

Joe,
You are correct about the reading... & I am like you on the range of pipe length. I would say hit in there some where in his range. That is exactly how I had my headers built for my V-6 in a Gen 3. Even the steps vary some. They seem to work well. After all the header is just Rocking the TQ Curve up or down...
2 " on a 32" pipe is about 6%.. off the top of my head..

Re: Length of header primaries
 

I talked to Calvin for about 30 minutes today......great guy , really knows his header design....fun talking with him. He asked me how I found him...I dropped your name , he knew / knows of , you.
In summary , he suggest more emphasis on the collector ( make that a merge) as a way of influencing the relationship between a primary too short or too large and its connection to recovering torque (in the event of too large a primary )...or , a smaller collector.

Re: Length of header primaries
 

i have built a few sets of headers for street cars,stockers and chassis cars ,, in a stocker engine bay is very challenging to map out your equal lengths, but being careful not to create restrictions by trying achieve equal lengths ,i always try to plot out the smoothest paths with out to many bends and using bigger radius bends where i can , collector sizes are like camshaft choices, you can get close but to find that perfect combo dyno testing is key to getting the most out of the combo, but as you know there just isn't enough time to test everything
in my opinion you want to focus on what you can build for torque ,,most carbureted stocker engines are done making power between 6200-6700 ,, torque around 4500 -5000,,,

gmonde