View Single Post
Old 12-10-2009, 06:33 PM   #8 (permalink)
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 11,635
Thanks: 18,694
Thanked 6,063 Times in 3,708 Posts

engine tuning is kinda like algebra,whatever you do to one side of the equation,you've got to do to the other.
In the olden days of carburetors,you would have to re-meter the intake and probably change ignition timing to get the full benefit of the muffler,if not alter the whole intake tract.
With modern EFI you're probably safer there,although you are physically altering the tuning of the entire engine,and could stand to lose some low end and mid-range performanece as you kill back-pressure and it's beneficial scavenging effects.
And for "normal" rpm range driving,I suspect it will make no improvement.
Calculate your flow rate,and internal velocities based on the inside diameter of stock vs new muffler for say 2,000-2,500 rpm.I think you'll be amazed at how slow those gases flow after initial blowdown.
  Reply With Quote
The Following User Says Thank You to aerohead For This Useful Post:
dwhitney89 (12-11-2009)