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Some days my borla appears to be louder and some others quieter. One of these days I'll measure it with my meter to see if it's all just in my head, the difference it's noticeable though.
Some days my borla appears to be louder and some others quieter. One of these days I'll measure it with my meter to see if it's all just in my head, the difference it's noticeable though.
Don't quote me on this but I read somewhere that it's the new packing material inside the mufflers that "break in" during the initial heat cycles, it causes them to better absorb the sound which in turn quiets them down. The Borla muffler/resonator has several layers of sound absorbing material made from stainless steel and ceramic, other manufacturers like Flowmaster just use chambers and baffles so the sound levels on those types of mufflers shouldn't change over time.
Same thing happened with the Tanabe Touring Medallion on my IS350. First week it was crazy loud and droned on the freeway, after about a month it was almost as quiet as stock.
Maybe somebody who has more knowledge on this subject can chime in.
In my experience with aftermarket exhausts, they always get louder over time. The packing wears down and can no longer absorb as much sound. This of course occurs over many years of usage.
It does make sense that the packing would need a few heat cycles to work as designed, which would explain the drop in sound after a break in period. But I don't see how it will get any quieter with years of use.
I would really love to get a novel full exhaust but the price just kills it for me. I have been contemplating a borla exhaust for quite some time and maybe I will finally do it with those types of gains!
The catback kits are from the primary cats back. They lose the secondary cats and the resonator, but the primary cats (we have 4 cats total) are part of the stock manifolds. Add some PPE or Sikky headers and there ya go!
If you didn't have proof I would have never believed this. I have never owned a car that got such substantial gains from an exhaust... and a borla none the less. That is really impressive!
If you didn't have proof I would have never believed this. I have never owned a car that got such substantial gains from an exhaust... and a borla none the less. That is really impressive!