3" catback exhaust upgrade. Surface treatment questions.

[Charlie207]

I bought a 3" catback consisting of T409 pipes & muffler. I also live in NH, where they dump salt & spray/pre-treat the roads with brine. It kills cars new and old.

I assume that the exhaust will last at least 5 years, which is probably as long as I'd reasonably expect this Yukon to last me anyways.

But, I'd like to try something similar to what I read about in THIS FORD FORUM POST where they applied a high-temp rust-preventative primer & and high-temp paint prior to installation.

Once this thing gets here I'll realize that I probably need to find a more quiet muffler to swap to, but that's a future problem.

 

[Thrust]

409 has less nickel and chromium than 304 so it will rust.
I think it's a great idea to use high temp primer or paint on it. Will definitely make it last.

 

[Joseph Garcia]

A fellow NH member. Nice. @Fubar0715 is also in NH.

I have a Gibson Extreme cat back stainless steel exhaust system for 3+ years now, and there is only minor surface oxidation on the system at this time. Besides, my Gibson exhaust system is warranted for life, so I have no concerns.

You can certainly try to put a high temperature coating on it, but if you do, make sure that you surface treat the system to remove all manufacturing oil residue before applying the coating.

 

[Charlie207]

A fellow NH member. Nice. @Fubar0715 is also in NH.

I have a Gibson Extreme cat back stainless steel exhaust system for 3+ years now, and there is only minor surface oxidation on the system at this time. Besides, my Gibson exhaust system is warranted for life, so I have no concerns.

You can certainly try to put a high temperature coating on it, but if you do, make sure that you surface treat the system to remove all manufacturing oil residue before applying the coating.

Yeah, I was going to refer to the good info in the post I linked. Seems straight forward enough.

 

[Charlie207]

FedUPS just dropped it off, and initial thoughts....

Packed reasonably well with no rattles.

Initial mock-up to see if the pipes would fit together easily... and they do slide together with minimal effort.

Catalytic coverter joint. Seller confirmed it will mate to the 2.75" factory joint.

Weld inside.... looks like a robot did it.

Muffler: 21" body, 26" overall, 6" diameter. I think it's going to be loud.

Yeah....

Robot welds...

The crush clamps that came with it. I bought some wide 3" band clamps to use instead.

Overall, I'm not horrified with it, for supposedly being T409 for a 3" exhaust, $300 shipped. I put some calipers on the tubing, and it's actually 2.875" tubing expanded to 3" at the ID of the muffler/tube joints. I'm not an exhaust pro, so I don't know if that's correct for a supposed 3" system, but I hope the 3" band clamps can tighten down enough.

I'm going to try to run out to the AutoZone near me and get some high-temp primer and black paint. Chome is icky...
Hopefully this weekend I can get it painted and installed. I am a bit worried it's going to be loud and drone without a resonator near the tip. I'm already looking for replacement mufflers that have the same overall dimensions.

 

[Fubar0715]

I agree about the chrome - personal preference. @Joseph Garcia Joe has dual exhaust living behind the 6.2L in his Denali but I considered going that way too but plan to go the route of a black stainless tailpipe that I saw on @RichardCranium Darren's PPV. Good luck with getting it all fitted together and look forward to your thoughts on the system.

 

[Fless]

FedUPS just dropped it off, and initial thoughts....

Packed reasonably well with no rattles.
View attachment 382843

Initial mock-up to see if the pipes would fit together easily... and they do slide together with minimal effort.
View attachment 382844

Catalytic coverter joint. Seller confirmed it will mate to the 2.75" factory joint.
View attachment 382845

Weld inside.... looks like a robot did it.
View attachment 382846

Muffler: 21" body, 26" overall, 6" diameter. I think it's going to be loud.
View attachment 382847

Yeah....
View attachment 382848

Robot welds...
View attachment 382849

The crush clamps that came with it. I bought some wide 3" band clamps to use instead.
View attachment 382850

Overall, I'm not horrified with it, for supposedly being T409 for a 3" exhaust, $300 shipped. I put some calipers on the tubing, and it's actually 2.875" tubing expanded to 3" at the ID of the muffler/tube joints. I'm not an exhaust pro, so I don't know if that's correct for a supposed 3" system, but I hope the 3" band clamps can tighten down enough.

I'm going to try to run out to the AutoZone near me and get some high-temp primer and black paint. Chome is icky...
Hopefully this weekend I can get it painted and installed. I am a bit worried it's going to be loud and drone without a resonator near the tip. I'm already looking for replacement mufflers that have the same overall dimensions.

If I didn't know better I'd think that @Dantheman1540 made those welds.

 

[Thrust]

Considering the price of stainless these days, that's a smoking good deal.

 

[Tonyrodz]

FedUPS just dropped it off, and initial thoughts....

Packed reasonably well with no rattles.
View attachment 382843

Initial mock-up to see if the pipes would fit together easily... and they do slide together with minimal effort.
View attachment 382844

Catalytic coverter joint. Seller confirmed it will mate to the 2.75" factory joint.
View attachment 382845

Weld inside.... looks like a robot did it.
View attachment 382846

Muffler: 21" body, 26" overall, 6" diameter. I think it's going to be loud.
View attachment 382847

Yeah....
View attachment 382848

Robot welds...
View attachment 382849

The crush clamps that came with it. I bought some wide 3" band clamps to use instead.
View attachment 382850

Overall, I'm not horrified with it, for supposedly being T409 for a 3" exhaust, $300 shipped. I put some calipers on the tubing, and it's actually 2.875" tubing expanded to 3" at the ID of the muffler/tube joints. I'm not an exhaust pro, so I don't know if that's correct for a supposed 3" system, but I hope the 3" band clamps can tighten down enough.

I'm going to try to run out to the AutoZone near me and get some high-temp primer and black paint. Chome is icky...
Hopefully this weekend I can get it painted and installed. I am a bit worried it's going to be loud and drone without a resonator near the tip. I'm already looking for replacement mufflers that have the same overall dimensions.

That definitely will be loud.

 

[89Suburban]

That definitely will be loud.

I'm already feeling the regrets LOL.

 

[Charlie207]

Someone find be a swap? 26" OAL / 20"-21" body 3" ID.

It's date night with my better three-quarters, and I have to put the internet away.

 

[iamdub]

I don't think it'll be terribly loud nor drone badly. At least swapping in mufflers will be easy.

 

[iamdub]

Someone find be a swap? 26" OAL / 20"-21" body 3" ID.

It's date night with my better three-quarters, and I have to put the internet away.

Would be about stock volume at idle but with a stronger rumble and with a louder bark at hard throttle: https://www.amazon.com/AP-Exhaust-Products-XS2579-Muffler/dp/B004A5OBVA

 

[Charlie207]

Would be about stock volume at idle but with a stronger rumble and with a louder bark at hard throttle: https://www.amazon.com/AP-Exhaust-Products-XS2579-Muffler/dp/B004A5OBVA

Maybe something like this in place of the exhaust tip. But, have it tucked up under the bumper cover enough to look similar to the stock resonator turn-down?

3" Muffler

 

[iamdub]

Maybe something like this in place of the exhaust tip. But, have it tucked up under the bumper cover enough to look similar to the stock resonator turn-down?

3" Muffler

View attachment 382925

I don't see that making a whole lot of difference. It might clean up a slight bit of rasp at high RPM as heard from outside the vehicle. But, not $65+ worth of difference. You can get a whole other muffler for $65 and not need special after-muffler additions.

 

[Charlie207]

I don't see that making a whole lot of difference. It might clean up a slight bit of rasp at high RPM as heard from outside the vehicle. But, not $65+ worth of difference. You can get a whole other muffler for $65 and not need special after-muffler additions.

Good point.
I found the AP muffler you linked for $cheaper on Summit. https://www.summitracing.com/parts/aph-xs2579

I'm going to install the system as it is, and am priming/painting it now. My gf said she won't care if it's loud.

The JBA catback i had on my Armada was great quality, but pretty loud. This didn't bother me, but the drone at cruising speed was super annoying.

 

[Charlie207]

I wonder if I could cut the JBA muffler out from under my Armada, and use that???

 

[iamdub]

Good point.
I found the AP muffler you linked for $cheaper on Summit. https://www.summitracing.com/parts/aph-xs2579

I'm going to install the system as it is, and am priming/painting it now. My gf said she won't care if it's loud.

The JBA catback i had on my Armada was great quality, but pretty loud. This didn't bother me, but the drone at cruising speed was super annoying.

I saw it cheaper there, but their shipping charges make it higher than Amazon unless you don't have Prime.

Definitely give it a shot! You have nothing to lose. You might like it. At least your gf is cool with it!

If you like the volume and sound and only have a problem with it at a certain RPM (drone when cruising), you can attack just that frequency with a cheap piece of pipe and some math. You'll kill the drone but not muffle everything else, which negates the point of getting a louder aftermarket system.

 

[iamdub]

I wonder if I could cut the JBA muffler out from under my Armada, and use that???

Highly likely. Physical fitment is the only real hurdle and that's easy to overcome with offsets or even just welding a straight piece of pipe at an angle if needed.

 

[Charlie207]

If you like the volume and sound and only have a problem with it at a certain RPM (drone when cruising), you can attack just that frequency with a cheap piece of pipe and some math. You'll kill the drone but not muffle everything else, which negates the point of getting a louder aftermarket system.

Can you explain the "piece of pipe" used to cancel the drone wavelength?

It's all on the truck now, and I'm going through the paint curing heat cycles.

Idle 10 mins, cool 10 mins.

Idle 20 mins, cool 20 mins.

Drive 30 mins, let cool.