OEM Muffler Capabilities ?

[Biggfoot44]

More out of curiosity than any plans .

I've been going down the YT rabbit hole on exhausts , and got to thinking .

Context : Retained stock Cats . 3 inch main pipe diameter, 2.25 inch tail pipes . Stock 5.7L engine .

I get the impression that only midway down the rabbit hole , the Cats are the limiting factor.

Are there any actual numbers floating around as to dyno / time slip / carefully measured MPG of OEM muffler vs ( fill in blank , well regarded performance muffler ) . Other than the obvious esthetic pleasures of more Rumpa Rumpa , ticking off the neighbors ?

 

[Bigskyroadglide]

IMHO, without finding actual dyno results. Which exist but every dyno is different so very un comparable.

Remove the messed up smash point where the two head pipes get jammed into a 3 inch single pipe, by either putting a decent y pipe in or running true dual back to two performance muffler then connect your tail pipes. Cost $350 to $500 depending on what you buy. It will sound better and you might conservatively pickup 20 hp and lose some tq. $500/ 20 = $25 per hp.

The cats will flow more than you think.

If no. Then drop the 2k+ on a set of long tubes and go from there, including unlocked PCM, tuning, software and the like, more if you don't install long tubes yourself.

5k later, you, as a wild guess might make about another 80 hp, and pickup 65 tq. $5,000 / 80 = $62.5 per hp.

Sound about the same.

Your $$ your call. The truck will respond to exhaust mods, but you can get deep fast. Long tubes address the cats, but there is more to it

 

[Wild one]

A properly built 3.5" single exhaust will provide more gains then a pair of 2.5" dual pipes will,as it promotes better cylinder scavenging.But it has to be made using mandrel bends as normal crush bends defeat any gains

 

[Hanover Fiste]

Years ago I read where someone installed a $1500 cat-back system on a then-new 2005 and gained only about 10 HP. The stock system is already sufficient for day-to-day driving.

 

[Biggfoot44]

Years ago I read where someone installed a $1500 cat-back system on a then-new 2005 and gained only about 10 HP. The stock system is already sufficient for day-to-day driving.

No doubt Big Sky and Wild One are on point about how to do it right from scratch. ( But no , l'm not going down that $$ rabbit hole anytime foreseeable. )

Hanover Fiste quoted above seems closer to my curiosity.

Is his memory in the ballpark for muffler swap only , no other changes , being 10 -ish HP in the right neighborhood?

 

[jc56berg]

Exhaust is an interesting topic for me, not just for the sound but for the added performance. I went with AFE shorty's and retain stock y-pipe w/oem cats and a Borla ATAK cat back. Stock, locked pcm. Noticeable low end with the shorty's. At the time of install the truck even idled very smoothly 500 rpm's lower and maybe even picked up 2-3 extra miles to the tank full. H-Town stop and go traffic is a gas eater. Truck does very well on the open road. I have been to two muffler shops and both have said that the removal and replacement of the crushed double pipe will make NO difference. Truck is a daily driver and doesn't see high rpm's (4000-4800) to get on the freeway or passing. Not looking to throw money away (I just today filled up ). Any thoughts on the crushed pipe please pass on to me.

 

[Nick@GotExhaust]

The 2 biggest limiting factors in your exhaust are the crushed y pipe and restrictive manifolds. Long tube headers are the single biggest bolt on power gain you can do for your RAM. They replace both the manifolds and y pipe.

Message me when your ready to go down the rest of the way down the rabbit hole and want to make some power gains!

 

[Bigskyroadglide]

Here's the cheapest best sounding replacement muffler for a ram in my humble opinion. Don't need headers, pickup some noise for the neighbors and a few tens in mpg, if you can keep your foot out of it

https://a.co/d/0bkhxtWp

About a 1.5 hour install depending on the state of your existing exhaust system

 

[pacofortacos]

I will say this, I have the 3" single in/out oem muffler and just changing the tailpipe for the OEM single 3" to a OEM single 6.4L 3 1/2" tailpipe does slightly change the way that the truck runs - it moved the torque curve around just a bit but it was enough to notice.
Biggest difference is the 6.4 tail pipe makes the truck much more quiet vs. the standard 5.7 single tailpipe.
There is a difference in lower rpm performance and mpg - I just don't remember exactly what.
I want to think that the stock 3" OEM single tailpipe gave a slightly lower mpg BUT a more consistent mpg.
Where as the 3.5" 6.4 tailpipe would give slightly higher peak mpg but mpg varied more overall - both on highway mpg @ 74 mph.

The 6.4 3 1/2" in/out oem muffler made the truck whisper quiet - I don't remember what other differences with the muffler - I should have removed the internal valve and tried it, but I no longer have that muffler to test with.

 

[inuyasha-rules]

Dyno days are coming up soon and if I have the day off I'll stick my truck on there just for giggles. It was modded before I bought it, with regeared rear end, ram air intake, magnaflo muffler and a mild tune. It's definitely got more power than a stock 5.7, and I kinda want to know how much.

 

[Wild one]

Exhaust is an interesting topic for me, not just for the sound but for the added performance. I went with AFE shorty's and retain stock y-pipe w/oem cats and a Borla ATAK cat back. Stock, locked pcm. Noticeable low end with the shorty's. At the time of install the truck even idled very smoothly 500 rpm's lower and maybe even picked up 2-3 extra miles to the tank full. H-Town stop and go traffic is a gas eater. Truck does very well on the open road. I have been to two muffler shops and both have said that the removal and replacement of the crushed double pipe will make NO difference. Truck is a daily driver and doesn't see high rpm's (4000-4800) to get on the freeway or passing. Not looking to throw money away (I just today filled up ). Any thoughts on the crushed pipe please pass on to me.

Shorties Do Not make more low end torque,that's a placebo effect created by your mind,your butt dyno is wrong,lol.Your exhaust operates the same as your intake manifold,the long runners in the intake create torque,while the short runners create high rpm horsepower,your exhaust is the same.You want long tubes to create torque.Your exhaust guys are wrong about the crushed Y pipe, fixing it will create a bit more power

 

[pacofortacos]

Wild one but at what rpm will the better Y pipe show any gains?
Will it help with towing in the 2000-2500 rpm range?
I don't think so, but could be wrong and is why I never bothered with it - well that and the lifetime service agreement

 

[Wild one]

Wild one but at what rpm will the better Y pipe show any gains?
Will it help with towing in the 2000-2500 rpm range?
I don't think so, but could be wrong and is why I never bothered with it - well that and the lifetime service agreement

It's definitely not going to hurt your low rpm torque capabilities thats for sure

 

[pacofortacos]

I have to see if the lifetime service agreement covers the Y pipe, if it does then that's a no go.

 

[Biggfoot44]

The 2 biggest limiting factors in your exhaust are the crushed y pipe and restrictive manifolds. Long tube headers are the single biggest bolt on power gain you can do for your RAM. They replace both the manifolds and y pipe.

No doubt .

But still curious about Muffler Alone , with the rest stock .

Are the Manifolds & Y Pipe the primary Limiting Factor ? Sufficiently so that muffler is then negligible, unless the " before " really sucks ?

Or are mufflers a significant factor still , despite the OEM manifolds , Pipes, and cats ?

 

[Biggfoot44]

Here's the cheapest best sounding replacement muffler for a ram in my humble opinion. Don't need headers, pickup some noise for the neighbors and a few tens in mpg, if you can keep your foot out of it

https://a.co/d/0bkhxtWp

About a 1.5 hour install depending on the state of your existing exhaust system

OK . If you're going for simple & inexpensive , with a " small , straight thru muffler w/ built in split for dual outlet " , dors the above really do anything significantly different from this ?

 

[Wild one]

OK . If you're going for simple & inexpensive , with a " small , straight thru muffler w/ built in split for dual outlet " , dors the above really do anything significantly different from this ?

View attachment 583033

All you'll gain from a muffler swap is noise,it's not gonna give you any power that you can actually feel.The choke points are the log manifolds and the Y pipe. The trucks really respond to a set of long tube headers and a tune for the headers.

 

[Biggfoot44]

All you'll gain from a muffler swap is noise,it's not gonna give you any power that you can actually feel.The choke points are the log manifolds and the Y pipe.

Ah Ha ! What l was seeking.

 

[Wild one]

Ah Ha ! What l was seeking.

Costs money to gain anything from a Hemi,if you want an actual power gain from the exhaust system,you're going to have to buy a set of long tube headers and tune the truck.Long tubes and a tune are one of the better bang for bucks mods you can do to the trucks,about the only thing that'll beat them for cost to horsepower ratio is Nitrous.

 

[crackerjack1957]

Costs money to gain anything from a Hemi,if you want an actual power gain from the exhaust system,you're going to have to buy a set of long tube headers and tune the truck.Long tubes and a tune are one of the better bang for bucks mods you can do to the trucks,about the only thing that'll beat them for cost to horsepower ratio is Nitrous.

Laughing gas will make the ones in the rear cry.........LoL