PSA for those with Aftermarket Exhaust

[ConspicuousConsumption]

Today I learned. Never knew about such things. Off to get my drill

 

[speedracer05]

That's it? That's not bad. I had no idea but that seems easy enough.

 

[ConspicuousConsumption]

Believe it or not, 3.25 cups out of mine. The driver side was 2.5 cups, mostly just yellow. My passenger side was sooty, which lines up with my passenger side having terrible exhaust tip dirtiness. Still not sure why.
Thermal 2.5”

 

[Toadster]

3/16” is more than enough…either the front or lowest end of the muffler right at the seam and in the center.

would one in front and back be recommended? or just one hole is good enough?
has anyone confirmed the sound improvement/un-improvement after the water is drained?

 

[nyuk98GT]

Toadster,

Borla instructions for Mustang mufflers (circa 2012 - some, not all mufflers) were to drill a 1/16" dia. hole about 1/8" from the weld seam at the inlet end of the muffler. The hole should be located on the centerline of the endplate bottom of the muffler. Borla's instructions had a note that only certain mufflers needed the drain/weep hole and it was recommended to call to confirm if a specific (Borla) muffler needed to be drilled.

edit/
Edited to correct hole location from bottom of the muffler to the bottom of the sideplate. I went back to the first page and started reading and came across post #31 by "THNX SVT" (thanks for posting that link to the Borla instructions).
/end of edit

HTH

 

[Toadster]

Wow so on the inlet side - weird?!

 

[UNBROKEN]

Wow so on the inlet side - weird?!

Not really. Most cars have a slight rake so the inlet side is generally the low side. You want the hole on the low side.

 

[Toadster]

Not really. Most cars have a slight rake so the inlet side is generally the low side. You want the hole on the low side.

I guess I just think the air is flowing backward but LOL

makes sense