I ran a pair of the same 2.5: Dynomax Ultra Flow (17222) mufflers with a JR flat collector set of headers, 3.5" collectors, 3.5" head pipes (almost to the mufflers), and reduced down to the 2.5" (very short) opening at the front face of the mufflers. "Down turns" right after the mufflers.
The exhaust was designed like a Holley carb center main body: Large front section, venturi,
then an expansion into the muffler.
I saw very little difference in power between the open collector performance and the closed exhaust.
It will be interesting to see how much different the VOE mufflers are with the 3" stainless head pipes
I have from the HO Racing Tri-Y headers going on the car in the near future.
Tom V.
Try it and see what you come up with.
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"Engineers do stuff for reasons" Tom Vaught
Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward.
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