Drilling weep holes into new Borla?

[Cmitchen53]

I recently installed new Borla S Type (w/active) on my 19 GT. I was wondering if anyone else has ever drilled “weep holes” on the furthest lower point of the rear face plate? I’ve read a couple forums on other sites saying after you drill them people are getting almost half a gallon out of each muffler of water. (condensation) I’ll probably end up giving Borla a call later today. Any advice or info is appreciated!

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[cosmo73]

I don’t have an answer for you but do have Borla S type mufflers and would like to know if this is beneficial.

 

[Cmitchen53]

I don’t have an answer for you but do have Borla S type mufflers and would like to know if this is beneficial.

I’ll keep you posted! It can allegedly affect and distort the sound of your borla system. And not to mention the added weight and water just sitting in there potentially deteriorating your mufflers.

 

[Coosawjack]

I asked Magnaflow about drilling a weep hole in their mufflers and they promptly said it would VOID their Lifetime Warranty.....GO FIGGER??

Good Luck and curious what Borla might have to say??

 

[I Bleed Ford Blue]

I’ll keep you posted! It can allegedly affect and distort the sound of your borla system. And not to mention the added weight and water just sitting in there potentially deteriorating your mufflers.

The mufflers are made from 304 stainless so they won't rust out, so the deteriorating is a non issue.

 

[Coosawjack]

My Magnaflows were too........welds musta been mild steel since they rusted out at the welds!!

I still wonder why Magnaflows have no weep holes when most OEM mufflers have holes to drain moisture!!??

 

[dn1984]

doesn't it get blown out when you drive it anyways?

 

[Coosawjack]

My Marauder mufflers where mounted in front of the rear axle and you'd expect them to get hotter than rear mounted Mustang mufflers??

I'd expect the Mustang mufflers to actually hold more water since they wouldn't get as hot depending on driving style??

 

[Idaho2018GTPremium]

Let us know what Borla says. I have a feeling they will say don't drill a hole in the muffler. That said, if your Borla muffler starts to corrode and opens up like that Magnaflow up there, they should replace it under the million mile warranty.

 

[Cmitchen53]

Yep....

You drilled into your S-Types?

 

[Cmitchen53]

I attached the drain hole instruction straight from Borla. I haven’t been able to get a hold of a Borla Technician yet. I’ll keep trying. See attached PDF.

 

[Dr. Norts]

I drilled mine way back when and followed those same borla instructions.

Be careful as the bit is about to fully go through the metal. When it did on my pass muffler the bit side loaded and snapped. Goddamn muffler ate it lol.

Quite a bit of water came out of mine I wouldn't say it was a half gallon (1892ml) but it was at least 3 cups full (750ml). More than I'd want in my mufflers just sitting there that's for sure. It could also create problems if you put your car away for winter storage with the mufflers full. Ice forming will break / bend anything in it's path.

 

[I Bleed Ford Blue]

My Magnaflows were too........welds musta been mild steel since they rusted out at the welds!!

I still wonder why Magnaflows have no weep holes when most OEM mufflers have holes to drain moisture!!??

In my experience, magnaflow cheaps out on the stainless they use, they only use the better 304 on the outermost shell of the mufflers. The pipes, inner structure of the mufflers, the hangers are all 409, a much cheaper grade of stainless that will eventually rust out. That's why magnaflow is cheaper pricewise than most other brands. On the other hand, companies like borla use 304 thru-out the entire cat back system

 

[WD Pro]

A couple of random observations from me :

Surprised at the photo that Borla used - weld quality on the pipe exit isn’t the best for an official photo ?!

As already mentioned - that photo of the rusted out muffler has me thinking it’s not 304 ? 304 under most conditions will show little more than some mild surface discolouration (not normally rust coloured either).

WD

 

[I Bleed Ford Blue]

WD your right, I forgot about that. They are probably just 409 stainless. or it was a counterfeit muffler made to look like a magnaflow. On the past magnaflow systems I had, only the pipes had surface rust, the mufflers and tips were still shiny even after several years of winter driving in the rust belt. I have always known magnaflow to be a "Legit" company who stands behind it's product and doesn't claim its product is what its not. So maybe the bad muffler was a counterfeit. Maybe at one time they made mufflers entirely out of 409, but I've never heard of it.

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