Help me Select Exhaust

pcruis1 · August 29, 2016

I've done a bunch of research and read 100s of pages on this forum. I've narrowed it down to two choices. First, is the GM Borla, which is about $1k plus the cost of the tips. I understand this is not a loud exhaust, but shouldn't have any drone, and should sound very "professional." Second, for some reason, I like the idea of the MagnaFlow Offroad Pro. I have a custom tune, and my guy can turn off the AFM, but i do have concerns that the Magna Flow will be too loud and not last as long as the higher quality Borla. Then again, the cost of the MagnaFlow is 1/2 the cost of the GM Borla. I drive about 25k miles per year, so I'm leaning towards the more conservative route, but was hoping someone might convince me the other way. Thanks in advance.

seansharley · August 29, 2016

It's my understanding there's no "bolt on" exhaust guaranteed to improve performance, just sound. So why not just remove the third cat, and see what you think? Save some $$ and get the sound, if that's what you're looking for.

camcamaro1991 · August 29, 2016

I have the GM Borla, I would highly recommend it for quality it will last. Yes its quite (PS you can swap the muffler out with the sport muffler as the primary cat back is the same for GM Borla and Borla kits the only difference being the Intermediate pipe, having the flex join on the GM Borla is better than the straight pipe on the Borla.... ask me how I know!), but again these trucks are more quite than the previous trucks. If you spend a lot of time in your truck keep it quite noise pollution wears me out on long drives.

^ posted just after Sean, but Sean that's incorrect. GM's new "Corsa" type exhaust is on the Silverado/Sierra All Terrain X, it adds 10Hp to the 5.3 SAE and I believe 7HP to the 6.2 SAE. (10hp is hardly measureable to the driver) There is no way to remove the 3rd cat without any damage to y pipe & warranty, to hollow it out its what guys do so it appears to be stock, at stock power levels the 3rd car really doesn't make any sense in effort spent to hollow it out.

SouthernSilveradoGuy85 · August 29, 2016

I have the GM Borla, I would highly recommend it. yes its quite, but again these trucks are more quite than the previous trucks

^ posted just after Sean, but Sean that's incorrect. GM's new "Corsa" type exhaust is on the Sierra All Terrain X, it adds 10Hp to the 5.3 SAE. there is no way to remove the 3rd cat without any damage to y pipe & warranty, to hollow it out its what guys do so it appears to be stock, at stock power levels the 3rd car really doesn't make any sense in effort spent to hollow it out.

I don't see how removing the 3rd cat would damage anything. I've also read that the 3rd cat is already pretty hollow, it's not like a normal cat. About the warranty, if replacing even just the muffler can void the warranty then removing the 3rd cat won't make a difference. The 3rd can is also not monitored like the normal cats so I don't see how it would void the warranty anyways, just like how changing the exhaust would. The 3rd cat is just to make it Cali legal.

piratepenguin · August 29, 2016

I was going back and forth between the GM Borla and the S-Type Borla. After my research i realized the GM was too quiet and wasn't enough of a difference over stock to warrant the 1k price tag. Thus i went with the S-Type. I love it. I have not needed to get a tune to remove the V4 mode either. I don't have any drone that annoys me to the point where it is necessary even though i was ready to purchase if it were needed.

pcruis1 · August 29, 2016

My practical side tells me to get the GM Borla due to the amount of miles I drive. That being said, I suspect that at some point in the near future my truck will not be my daily-driver, and thus, I wouldn't mind it being a little less practical. Thanks for the feedback guys. Keep em coming. Warranty is not an issue. I already have 60k miles on the truck.

camcamaro1991 · August 29, 2016

I don't see how removing the 3rd cat would damage anything. I've also read that the 3rd cat is already pretty hollow, it's not like a normal cat. About the warranty, if replacing even just the muffler can void the warranty then removing the 3rd cat won't make a difference. The 3rd can is also not monitored like the normal cats so I don't see how it would void the warranty anyways, just like how changing the exhaust would. The 3rd cat is just to make it Cali legal.

to "remove" the cat? its welded to the Y pipe.

to hollow it out.. its only worth 5hp and a little sound. its a 3rd cat just like the other 2 cats same material and same honey cone design, just no 02 sensors.

Don't even get me started on what the Dealers will do when you remove it or find that you hollowed it out. exhaust warranty is longer I believe 8 years and 80,000 miles

SouthernSilveradoGuy85 · August 29, 2016

to "remove" the cat? its welded to the Y pipe.

to hollow it out.. its only worth 5hp and a little sound. its a 3rd cat just like the other 2 cats same material and same honey cone design, just no 02 sensors.

Don't even get me started on what the Dealers will do when you remove it or find that you hollowed it out. (correction the OP is out of warranty)

All you have to do is make sure you cut it at the right spot. Basically just think about it before cutting. There's people on here that have removed the 3rd cat and replaced with a pipe with no problem.

camcamaro1991 · August 29, 2016

All you have to do is make sure you cut it at the right spot. Basically just think about it before cutting. There's people on here that have removed the 3rd cat and replaced with a pipe with no problem.

oh I am very capable person, I just don't think its worth it, I would rather bolt on a set of headers vs cutting off a 3rd cat.

Crew 6.2 took some pics of his process for hollowing it out. nice little how to and lots of pics here to showing the 3rd cat its just like the fronts. http://www.gm-trucks.com/forums/topic/162350-hollowing-out-the-3rd-cat/

Aldila · August 29, 2016

I have the GM Borla, I would highly recommend it for quality it will last. Yes its quite (PS you can swap the muffler out with the sport muffler as the primary cat back is the same for GM Borla and Borla kits the only difference being the Intermediate pipe, having the flex join on the GM Borla is better than the straight pipe on the Borla.... ask me how I know!), but again these trucks are more quite than the previous trucks. If you spend a lot of time in your truck keep it quite noise pollution wears me out on long drives.

^ posted just after Sean, but Sean that's incorrect. GM's new "Corsa" type exhaust is on the Silverado/Sierra All Terrain X, it adds 10Hp to the 5.3 SAE and I believe 7HP to the 6.2 SAE. (10hp is hardly measureable to the driver) There is no way to remove the 3rd cat without any damage to y pipe & warranty, to hollow it out its what guys do so it appears to be stock, at stock power levels the 3rd car really doesn't make any sense in effort spent to hollow it out.

Would the 10hp apply to the Corsa Catback 14873?

pcruis1 · August 29, 2016

I was going back and forth between the GM Borla and the S-Type Borla. After my research i realized the GM was too quiet and wasn't enough of a difference over stock to warrant the 1k price tag. Thus i went with the S-Type. I love it. I have not needed to get a tune to remove the V4 mode either. I don't have any drone that annoys me to the point where it is necessary even though i was ready to purchase if it were needed.

Pirate, the S type was on my short list as well - love the sound. Looks like it's slightly cheaper in price than the GM version (touring), but obviously louder. Good news that you're not getting much drone.

SouthernSilveradoGuy85 · August 29, 2016

oh I am very capable person, I just don't think its worth it, I would rather bolt on a set of headers vs cutting off a 3rd cat.

Crew 6.2 took some pics of his process for hollowing it out. nice little how to and lots of pics here to showing the 3rd cat its just like the fronts. http://www.gm-trucks.com/forums/topic/162350-hollowing-out-the-3rd-cat/

I would too and want to get headers, I was just saying that you can remove the 3rd cat without damaging the y-pipe which you said it would.

Waterfowler41 · August 29, 2016

Oh man I feel your pain about selecting an exhaust.

One word of advise, wait until this weekend to buy it if you can. Go to autoanything and go into their online chat. If the exhaust you want isn't already on sale or the current, probably Labor Day coupon code, doesn't apply, whine about it in the chat to them. They will knock %% of or even apply the current coupon code.

I was chatting with them this morning about the AFE rebel system and the guy randomly asked me if I wanted an enhanced price. I said yes and he dropped the $680 exhaust down 12% which beat Amazons price.

This will be the third exhaust system I buy from them because they are still saying competitive with Amazon.

Sent from my iPhone using Tapatalk

camcamaro1991 · August 29, 2016

Would the 10hp apply to the Corsa Catback 14873?

GM stated the GM performance exhaust 23442234 or 23442233 for L83 engine. I believe its Corsa or made by Corsa for GM. I think its save to say any decent name-brand cat back will add 10hp.

Pulled from the article listed on GM:

In true GMC fashion, the Sierra 1500 All Terrain X provides plenty of capability. A powerful 5.3-liter V-8 engine is standard, while a new stainless steel performance exhaust system delivers both a bold exhaust note and increased performance. In fact, with 33 percent less backpressure than the stock exhaust, All Terrain X’s performance exhaust provides a 10-horsepower gain over the base 5.3-liter V8, bringing peak power ratings to 365 hp at 5600 rpm and 383 lb-ft of torque at 4100 rpm.

http://www.gmc.com/gmc-life/trucks/sierra-1500-all-terrain-x.html#

BlueCrayon · August 30, 2016

I went through this very dilemma myself in the last few months. My thoughts:

I wouldn't get the GM Borla....personally not enough sound gain over stock for the $$.

I didn't like the magnaflow too much either....although nice deeper rumble, also thought too quiet.

I had actually just about convinced myself to get a Gibson sport because of decent sound and cheap, but I heard way too many stories about poor fit and leaking.

Same goes for the MBRP and I, personally didn't really like the sound, a little too raspy for me.

Really like the Flowmaster outlaw, but don't make for 2016 6.2L.

Same goes for Volant.

Pretty much made my way full circle to my 2 all-time favorites Borla (S or atak) and Corsa (sport or dB), just didn't want to spend that much money.

After hours of shopping around, finally just bit the bullet and bought the Corsa sport for 1000.

Going on Saturday...I'll let you know my thoughts...I had one on my LT1 camaro for a long time and loved it.