Kamauxx

iTrader: (1)

I'm wondering if anyone knows for sure, the outside diameter of the different size mufflers from Spiral Flow?

Summit says:

2.5" = 4" O.D.
3.0" = 4" O.D.
3.5" = 4" O.D.

This sounds to me like Summit just copied and pasted the same info. I don't understand how they can keep the same O.D. while changing the interior dimensions. Any info.?

gtpvette

iTrader: (2)

I have a pair of the 3",,, but the car is at home. I suspect Moroso uses the same center section of the muffler (where the spiral section is) and just welds on different front and back sections based on the exhaust pipe size used.

Kamauxx

iTrader: (1)

Wow, really? So going with a 3" over 2.5" muffler of this type will only make flow differences because the pipes have to be upgraded also then, right?

Full-Force

iTrader: (11)

its is 4"

SS4Luck

iTrader: (10)

i have the 3" in/out and my outer is 4"...

ss1

iTrader: (32)

I have 3" Spiral Flow's, and yes the OD is 4". Same deal for all of them, they all use the same cores, then open the ends up to the correct size for the inlet/outlets.

Kamauxx

iTrader: (1)

Thanks for the information everyone.