DIY stainless catback

[langston1726]

Thought I’d throw this out there for anyone looking for cat back alternatives and not wanting to spend $600 or more for a name brand stainless system. Sure you can just do a muffler swap or delete for much cheaper. My only issue with that is the factory pipe size on the 5.3s is 2.75” diameter so you’ll either have to use reducers or have someone weld it in place with a 3” or 2.5” muffler. 

 

I’m running a 3” Dynomax intermediate pipe and tailpipe. These are both direct fit on the 2014-2018 crew cab shortbed trucks and will use all factory exhaust hangers. Not sure on the double cab or standard bed. I’m currently running a Borla extension pipe, 19” Borla ProXs muffler, and an old Corsa pro series tip. The system is all clamped so I’m able to swap mufflers if I get tired of one and want to try something else. You may need to cut the extension pipe depending on the muffler length you decide to run just know you should have roughly a 30”-32” spread between the intermediate pipe and tailpipe. I have Texas Speed longtubes and catted Y pipe but this should bolt up to the factory y pipe. 

 

With all of this including clamps and depending on your choice of muffler and tip, you should have less then $400 in a full stainless catback. 

 

The Dynomax pipes are both 409 stainless steel and run around $100 each. Here are the part numbers

 

Dynomax intermediate pipe (pn 55608)

Dynomax tailpipe (pn 54704)

Borla 3” Ext pipe 304 stainless

choose one ($50-$65 each)

 (Part number includes 1 clamp)

 (pn 60564) 21” length

 (pn 60556) 15” length

 (pn 60554) 11” length

 

You’ll need to order 3 clamps if you decide not to have it welded. Hope this helps someone out. 

Edited January 19, 2022 by langston1726

[Snowcamo]

diggin your current setup. 

[16LT4]

Still expensive, not only in money but in time/labor .  I just installed a complete Proven Ground 3" 409 stainless cat-back system with flow-through muffler and 304 stainless tip.  The system bolted in without issue, didn't require any trimming/measuring/cutting/frustration, and included all stainless band-style clamps instead of u-bolt clamps.  Price?  $364, SHIPPED.

Edited January 19, 2022 by 16LT4

[Black02Silverado]

Thanks for posting this.  It gives options for those that like to tinker on their truck and enjoy doing it. 

Edited January 19, 2022 by Black02Silverado

[CamGTP]

I have the full dynomax catback on mine, runs a similar cost but obviously doesn't sound like yours.

 

Also the 409 stainless is cheap stainless, it surface rusts very easy and for sure anywhere with salt. I painted my exhaust with header paint prior to install.

[16LT4]

16 hours ago, CamGTP said:

Also the 409 stainless is cheap stainless, it surface rusts very easy and for sure anywhere with salt.

 

For sure, but still better than aluminized steel.  I don't know what the stock pipes were, but my intermediate pipe was very flaky, pitted and crusty, so if it was "Stainless", it was labeled by a marketer and not a metallurgist.  My cats, y pipe, muffler and exhaust pipe were in far better condition than the intermediate pipe.  

 

My winter-beater X3 is a 2008 with 186k miles and its entire exhaust system is pristine; it has a ground strap attached from the end of the intermediate pipe to the chassis to ground out stray voltage, so that may be part of the reason.  When I get around to it, I plan to ground my exhaust aft of the muffler somewhere to the chassis as additional rust-preventer.

[langston1726]

So far, I’ve only seen some surface rust on the hangers of these after a few years. I am in Oklahoma so the roads aren’t covered in salt for months like further north. 

Edited January 20, 2022 by langston1726

[LowRado17]

On 1/19/2022 at 10:58 AM, 16LT4 said:

Still expensive, not only in money but in time/labor .  I just installed a complete Proven Ground 3" 409 stainless cat-back system with flow-through muffler and 304 stainless tip.  The system bolted in without issue, didn't require any trimming/measuring/cutting/frustration, and included all stainless band-style clamps instead of u-bolt clamps.  Price?  $364, SHIPPED.

Just looked into the Proven Ground kit you mentioned. It looks pretty good for the price. Do you think it would fit a regular cab short bed? Maybe just trimming the intermediate pipe?

[16LT4]

6 minutes ago, LowRado17 said:

Just looked into the Proven Ground kit you mentioned. It looks pretty good for the price. Do you think it would fit a regular cab short bed? Maybe just trimming the intermediate pipe?

 

The kid came with another shorter intermediate pipe; between the 2 pipes (trimming the longer one may be required depending on model), all combinations of 1500 K2s are covered.  Of course, reach out to the seller/company to verify.  It fit my CCSB with no modifications necessary.

 

I love the sound, better throttle response and "cleaner" shift logic the transmission first started exhibiting once I installed the air raid jr.  It's too soon to tell for sure, but the last 50 miles, my fuel economy has gone up by 25% as well (I filled up after installing the system).

[M1ck3y]

Nice work, that's perfect for someone trying to figure out which muffler to go with. Can you get these in 304ss? As stated above salt/chemicals will hit 409 hard. I'm in the salt belt and 304ss gets surface rust; the lighter the gauge the worse it get's for some reason. 

 

For what exhaust companies charge for their 304 kits you should be getting 316. Major rip off imo.