I'm interested in a 1⅞ to 2 inch step header.
the pypes are what we run, they are a killer buy
yw, let me know if we can help
I'm interested in a 1⅞ to 2 inch step header.
Did you even read this thread? lol
I just have a hard time figuring out why anyone would want 2 inch headers, stepped or not, after reading this.Yes, of course. I had waited over a year to even post in this thread. So what did I miss?
I just have a hard time figuring out why anyone would want 2 inch headers, stepped or not, after reading this.
People in this post are over 1000hp on 1-3/4 headersIf they thought they might go F/I over 800 HP later, I could see buying headers once.
People in this post are over 1000hp on 1-3/4 headers
we also ran a 4" collector and 4" exhaust!!!!!
we also ran a 4" collector and 4" exhaust!!!!!
I get this question all the time, or more accurately I repeatedly talk customers out of going 'too large' with primary size.
Figured perhaps a thread is a better way to educate a little bit.
When it comes to headers, bigger is not always better. The easiest way to visualize this when it comes flow potential we can use math to see which primary size is best for a given exhaust diameter.
For the purpose of standardizing the math we will assume all headers have .050" wall thickness
Calculating the volume of exhaust flow is not easy, so we will focus on the area of the pipes for ease of comparison as volume is directly related.
Factory 2.75" OD exhaust has an area of 5.51 square inches
3.0" OD exhaust has an area of 6.60 square inches
Now it's time to calculate the area of the primaries.
Since these are V8 engines with dual exhaust the calculation for total area of the primaries would be 4x the primary size.
4 - 1 & 1/2" Primaries have a toal area of 6.15 square inches (Yes, larger than factory 2.75" exhaust)
4 - 1 & 5/8th" Primaries have an area of 7.30 square inches (A perfect size for dual 3" exhaust IMO)
4 - 1 & 3/4" Primaries have an area of 8.55 square inches
4 - 1 & 7/8th" Primaries have an area of 9.89 square inches
Given this information you can see unless you are running 3.5" + exhaust, there is no reason to run large primary headers.
Food for thought. You CAN go 'Too Big'.
http://www.onallcylinders.com/2015/...-at-the-science-behind-exhaust-header-tuning/
i have been making headers off and on for 30 years more or less. this is old tech. lost it seems on today's bunch.
I've been eyeballing the Doug Thorley headers as they have a Tri-Y design, but based on the pics I've seen online of their Coyote headers it seems they got the driver side correct but FUBAR'd the Passenger side. Looks like they designed the headers based on the old firing order, not the Coyote specific.