2500HD exhaust modification for towing/work

[Seabee15]

Well I've had my 06' 2500HD gasser for about 2 weeks and its bone stock and its killing me. I need to do something to it to make it my own. First modification would be to do something that would increase my MPG a little bit. So I decided to modify the air induction and exhaust. For the exhaust I was thinking something that wouldn't be to super loud, or for the most part drone in the cab. Its a CCSB and I tow and plow with it. I dont want an exhaust that would annoy customers or my crew / family. I was thinking of a Dynomax Flo X muffler straight out the back with dual 4" tips?

Anyone had any luck with these or have any suggestions????

[Brody57]

Well I've had my 06' 2500HD gasser for about 2 weeks and its bone stock and its killing me. I need to do something to it to make it my own. First modification would be to do something that would increase my MPG a little bit. So I decided to modify the air induction and exhaust. For the exhaust I was thinking something that wouldn't be to super loud, or for the most part drone in the cab. Its a CCSB and I tow and plow with it. I dont want an exhaust that would annoy customers or my crew / family. I was thinking of a Dynomax Flo X muffler straight out the back with dual 4" tips?

Anyone had any luck with these or have any suggestions????

Hate to break it to you but your not gonna gain much MPG out of it. The 6.0s are gas WHORES no matter what you do. Best mod you could do that would affect the mileage would be a Blackbear Tune. Anything else is a waste of time. As in exhaust for the 6.0s, im Spintech all the way. They sound the best on the 6.0s in my opinion.

[bowtieguy101]

I disagree completely. open the exhaust and let some air flow in. Wont be a very noticable change in MPG but will help. Then tune. Tune without exhaust and intake is just pissin in the wind.

[Quyonmob]

I disagree completely. open the exhaust and let some air flow in. Wont be a very noticable change in MPG but will help. Then tune. Tune without exhaust and intake is just pissin in the wind.

Please show me where the stock intake is incapable of flowing the required CFM to feed a 6.0L at WOT.

Minimal gains to be had with exhaust.

Custom Tune (not handheld) = removing TM, clean up shift points, best gain for power and mpg.

[Stratosman]

No need to change the exhaust on a 6.0 for performance, other than headers, it's the same as an 8.1 from the factory, plenty of flow

Tune with stock exhaust = 100% difference
Tune with exhaust = 103% difference
Tune with exhaust and intake = 105% difference

[speedracer326]

Tune without exhaust and intake is just pissin in the wind.

I'm gonna have to disagree with you there. I did tune before exhaust (my own) and the tune made a bigger difference than the exhaust. This is on an old 5.7 that had the 1 3/4" frontal piping, restrictive as balls, and the tune still made that much of a difference. Within the tune, TM made the biggest difference, then the timing table. After that, the gains were small.

[XLR8N]

I disagree completely. open the exhaust and let some air flow in. Wont be a very noticable change in MPG but will help. Then tune. Tune without exhaust and intake is just pissin in the wind.

Whatever you do, just don't listen to this guy. ^^^

[moop]

Whatever you do, just don't listen to this guy. ^^^

x2 on that, the stock exhaust and air intake flow great, but a blackbear tune will pay for itself

[TheBigBlackHD]

The 6.0s flow quite well. Cut that gigantic factory muffler out and get a nice, quality muffler. I'd go Spintech or Borla. My dual Borla XR-1s fvcking scream at WOT but have a very nice mellow tone at normal driving RPM. Never had a real load on it to see how it sounds under load. I have a K&N FIPK2 on my 6.0, it was on it when I bought it, but I like none the less. It probably hasn't helped anything performance wise but it sounds cool. A tune will def help! Factory tune KILLS the 6.0!!!!!!! Remove 100% TM and stiffen the shift points will make a world of difference (from what I've read, I havent invested in one yet). Like said above, the 6.0s love gas! I get ~10.2 in the city and ~11 on the highway. Only way your gonna knock down excellent mpgs with good power is get a diesel imo.

[Brody57]

The 6.0s flow quite well. Cut that gigantic factory muffler out and get a nice, quality muffler. I'd go Spintech or Borla. My dual Borla XR-1s fvcking scream at WOT but have a very nice mellow tone at normal driving RPM. Never had a real load on it to see how it sounds under load. I have a K&N FIPK2 on my 6.0, it was on it when I bought it, but I like none the less. It probably hasn't helped anything performance wise but it sounds cool. A tune will def help! Factory tune KILLS the 6.0!!!!!!! Remove 100% TM and stiffen the shift points will make a world of difference (from what I've read, I havent invested in one yet). Like said above, the 6.0s love gas! I get ~10.2 in the city and ~11 on the highway. Only way your gonna knock down excellent mpgs with good power is get a diesel imo.

:iamwithst hahahahahahaha!

[Drumaniac3000]

Please show me where the stock intake is incapable of flowing the required CFM to feed a 6.0L at WOT.

Minimal gains to be had with exhaust.

Custom Tune (not handheld) = removing TM, clean up shift points, best gain for power and mpg.

Exactly, if it cannot feed the engine at WOT they probably wouldn't have put it on the truck.

[Seabee15]

I swapped my Airaid intake tube from my 5.3 to my 6.0... I'm not sure if i like it... From the looks of it, The airaid tube looks to be smaller than the stock tube...

what are your guys input??

Oh yeah, I'm also swapping my K&N drop in filter from my 5.3 to my 6.0.... No Good?

[Quyonmob]

Oily MAF....

Paper filters are cheap, keep the most crap out of your engine, and can usually flow more than enough air for your engine at WOT.

[bowtieguy101]

I am noticing alot of people disagreeing with me. Thats fine. The factory exhaust will flow. But open it up with aftermarket adn it will flow BETTER, Then tune for greater results than a tune alone. This is nto the first time this has been done adn a simple dyno run will support everything I am saying.

[DarkCharisma]

Spark plug delete? :wink:


I disagree completely. open the exhaust and let some air flow in. Wont be a very noticable change in MPG but will help. Then tune. Tune without exhaust and intake is just pissin in the wind.

Stock intake flows plenty fine.

[TheBigBlackHD]

I am noticing alot of people disagreeing with me. Thats fine. The factory exhaust will flow. But open it up with aftermarket adn it will flow BETTER, Then tune for greater results than a tune alone. This is nto the first time this has been done adn a simple dyno run will support everything I am saying.

What people are saying is factory intake and exhaust is plenty capable for the 6.0L. Many people, like myself, will even go as far as saying the dual 3" exhaust is too much for the 6.0, after all its designed for the 8.1. Exhaust and an intake wont net the same gains as they would for say a 5.3 or 4.8. What the 6.0L need more than anything is a tune!!!! Factory tune kills the it!!!!!!!!!!!!!!!!

[DarkCharisma]

I am noticing alot of people disagreeing with me. Thats fine. The factory exhaust will flow. But open it up with aftermarket adn it will flow BETTER, Then tune for greater results than a tune alone. This is nto the first time this has been done adn a simple dyno run will support everything I am saying.


I won't disagree that an intake and exhaust typically sound better, and it's arguable whether or not they create any gain (I think the 3" exhaust on the 6.0L is excessive...), however for the cost of an exhaust ($350) and intake ($250), he could get modifications for proven gains... like an ECM tune.

A dyno shows that it gains power... at 5k RPM and higher. The engine only pulls so much air, the stock airbox, intake and exhaust is plenty of flow for an added 100HP (at least) on top of the stock output.

[RWSZ71]

I dont want an exhaust that would annoy customers or my crew / family. I was thinking of a Dynomax Flo X muffler straight out the back with dual 4" tips?

Anyone had any luck with these or have any suggestions????

IMO the dynomax x-flo muffler is one of the best sounding for the 6.0, however the drone in the cab is very loud. If you tow a lot I have to recommend not running the pipes straight out the back unless you want to deal with it every time hitching trailers, guess it matters what you are towing.

[DarkCharisma]

Exhaust != Power. The money is better spent elsewhere.

[bowtieguy101]

I won't disagree that an intake and exhaust typically sound better, and it's arguable whether or not they create any gain (I think the 3" exhaust on the 6.0L is excessive...), however for the cost of an exhaust ($350) and intake ($250), he could get modifications for proven gains... like an ECM tune.

A dyno shows that it gains power... at 5k RPM and higher. The engine only pulls so much air, the stock airbox, intake and exhaust is plenty of flow for an added 100HP (at least) on top of the stock output.

Not the size of the pipe thats resrictive, its the cat and the muffler. high flow cat adn high flow muffler will really let the tune come out.

[Quyonmob]

Not the size of the pipe thats resrictive, its the cat and the muffler. high flow cat adn high flow muffler will really let the tune come out.

No... the tune should be done to accomodate the any changes to the exhaust. Your statement implies the exhaust will improve the results of the tune, this is false. The tune will improve the results of the exhaust modifications. Refer to the amounts Stratosman posted.

[bowtieguy101]

Tuning without free flowing exhaust is reverse engineering. Get it flowing so the tune does what it should.

[rebelbowtie]

the factory HD cats are high flowing. the entire exhaust system is very well performing, unlike older GM vehicles. /argument

[Quyonmob]

the factory HD cats are high flowing. the entire exhaust system is very well performing, unlike older GM vehicles. /argument

this

[bowtieguy101]

They flow much better than older trucks, no doubt, but still more restrictive than most aftermarket .

[DarkCharisma]

k dude

[Jameslleary]

Stock mufflers are turbo design....not going to benefit from changing millions of $$ in engineering, with the exception of a tune, as a lot of vehicles AF ratio are a little fat from the factory.
Get a tune first , and go from there.

[speedracer326]

Except that stock design with all that R&D wasn't for performance, it's for quietness. I think the general concensus is that the muffler itself sucks while the rest of the system is up to par since it uses the same pipes as the 8.1.

[Jameslleary]

Except that stock design with all that R&D wasn't for performance, it's for quietness. I think the general concensus is that the muffler itself sucks while the rest of the system is up to par since it uses the same pipes as the 8.1.
Agreed, however, OE mufflers from about 01` have been a free(er) flowing Turbo design, with Hemholz resonators incorporated into them to help keep the noise down.
OE Pipes seem to be getting better and better...almost mandrel bent looking.
If a muffler change is to be done, I think a 30" round case Magnaflow will put a smile on his face, while still keeping his clients happy, but I don't think he will see enough of an MPG difference to justify the cost.

[6.0 Bowtie HD]

In my experience on my 05 2500HD changing the muffler didn't do much but make it sound better when I get on it. Which made my mileage worse because I want to romp on it all day long. I have the single Borla XR-1 on mine. I really need a tune. Its bit louder than the one your looking for but I love it. My mileage stays around 11 no matter what. Even with the mud tires and my heavier foot. Id pass on the air intake personally invest in the tune. I see your in Gulfport. What Batalion? I'm in Port Hueneme

[Benny00Z71]

Tuning without free flowing exhaust is reverse engineering. Get it flowing so the tune does what it should.

Is this thread dead now?

A custom PCM tune will will benefit some from exhaust and and intake. ORY and free flowing muffler help, but tunes can really be maximized with a heads and a cam...

It's not reverse engineering to remove TM, which a custom tune does. Also, even with everything stock, the spark tables can be changed to run optimally on premium gas, adding HP.

Lastly, just add some stickers. It's common knowledge slapping a couple on will add at least 50 HP. :rocking: