GM Borla exhaust measurement help

1300c · February 20, 2017

Please clamp it open first before spend a couple bucks..

I have a bunch of stainless steel hose clamps,and I plan on doing that first in the next couple of days. I did it on my 15 with stock exhaust, and didn't like the v4 sound. But I still want to remove each variable one at a time. I should've stated that earlier.

1300c · February 21, 2017

So I clamped the exhaust open, and that's not going to work. I've called Borla a couple times, and I can't get a consistent answer on the bypass pipe. One tech said it was to allow exhaust gas to bypass the valve allowing better valve operation due to it being in front of the muffler. The other tech the 2nd time I called said it was solely for cold weather starts, and not for better sound or valve performance.

1300c · February 26, 2017

Improved my flutter. I got under the truck, and noticed the flapper wasn't closing all the way. I fixed that, the flutter sound has decreased by at least 80-90% V4 sound has decreased a bunch to with no loss of performance.