6.0 With 4" Exhaust?

[hd01chevy]

i have had several different exhaust setup on my truck (01 ccsb 6.0)...have had magnaflow direct replacement muffler, too quite, 3" true duals..sounded mean as hell...now have flow pro dual in/out muffler....pipes are starting to rust out and was wondering if i could get a 4" exhaust for duramax to fit...also any idea what it would sound like....any input would be excellent

[04JJHD]

I think that would just be way too much flow for a 6.0, most people that have duals have 2.5"

[hd01chevy]

i have always had 3" on it since thats what was ran from factory,,...i know it woud have less back pressure, but is that good or bad, plan on using a 3" singlein/out flow,,that would help pressures some right..............just aasking

[Shatterz]

Ideally, with any motor you "in theory" want no back pressure, but in the real world this is not the case. An engine is basically an air pump, it sucks in air at the intake and pushes it out the exhaust. One of the things that keeps that air moving properly (since air is essentially a fluid) is velocity. In a perfect world you would want an engine that has no back pressure and very high velocity of air movement. But since this is virtually impossible there is some sacrafices you have to make to get good all around power. Having an exhuast system that is not too large contricts airflow somewhat but preserves a decent amount of air velocity, helping the motor move air more efficiently. This becomes important especially at low rpms, where the engine is not "pumping" as fast. Too large of an exhaust system will loose low end torque due to not enough "pumping" action and loss of air velocity. Granted when the engine is screaming @ 6K you'll see an improvment but this is not where you want peak power to be. These 6.0 motors seem particularly prone to loosing torque with exhaust modifications. 4" exhaust on this motor is unnecssary and you will only be loosing low end torque as a result. I would run a factory style single in/ single out muffler with 3" exhuast tubing. This way you can maintain most of the designed air velocity that makes these 6.0 motors run with good all 'round power.

[renegadeking]

Ideally, with any motor you "in theory" want no back pressure, but in the real world this is not the case. An engine is basically an air pump, it sucks in air at the intake and pushes it out the exhaust. One of the things that keeps that air moving properly (since air is essentially a fluid) is velocity. In a perfect world you would want an engine that has no back pressure and very high velocity of air movement. But since this is virtually impossible there is some sacrafices you have to make to get good all around power. Having an exhuast system that is not too large contricts airflow somewhat but preserves a decent amount of air velocity, helping the motor move air more efficiently. This becomes important especially at low rpms, where the engine is not "pumping" as fast. Too large of an exhaust system will loose low end torque due to not enough "pumping" action and loss of air velocity. Granted when the engine is screaming @ 6K you'll see an improvment but this is not where you want peak power to be. These 6.0 motors seem particularly prone to loosing torque with exhaust modifications. 4" exhaust on this motor is unnecssary and you will only be loosing low end torque as a result. I would run a factory style single in/ single out muffler with 3" exhuast tubing. This way you can maintain most of the designed air velocity that makes these 6.0 motors run with good all 'round power.

 

i couldn't have explained it any better and i totally agree with shatterz, PYPES (brand of exhaust) said you will only benefit from a 3'' or bigger pipe if you are putting out more than 450HP. and i was talking to a performance shop owner and he said you will lose all of your bottom end and he highly recommend against it.

[jro909]

you would lose more then gain with that big of pipe

[hd01chevy]

would the loss be extremely noticable.....like how bad of a low end loss......was thinking bout running 4" just because im curious of what it would sound like thru a flow and out my 8" tips....ya i know thats a big tip for a gasser but ive had em for 2yrs before it even became a big thing for diesels....i think they sound good thru my flo pro now but want something different from everybody elses 6.0 with pipes.....

[jro909]

your low end torque would suffer quite a bit

[slopez2500]

i have true duals, i believe the pipes are 3 inches, and i have 4.5 inch tips. sounds sooo sick

[yukon25008.1]

your gonna kil the truck, why would you want pipe that big?? its a little 6.0 right.. not a diesel?

besides the hp loss, the torque will suffer the most from lack of backpressure!

[[email protected]]

I have duals and they're 2 5/8" pipe. 4 inch is diesel territory, that would be ridiculous on any gas job.

[hd01chevy]

thanks all for the input...glad i asked before i ventured into this one....was just wanting to try something different, when i need new pipes i will just leave the setup on it i got.....had straights..definitely loud and mean...but after i put on mt flo pro i actually notitced it shifting better and towing better......must be the backpressure thing dunno.thanks again for input.

[Prokopchuk_9]

this is the kit i have

 

http://www.magnaflow.com/02product/shopexd...all&id=6418

 

its dual 3 inch IN single 4 inch OUT...i have a 5" tip on it. i never noticed any loss of power, in fact i thought it ran smoother. no low end power loss for sure. and it sounds amazing.

 

now 4 inch back from the collectors would be stupid i think. no backpressure. if you like big pipes buy a diesel. my buddy has 5 inch turbo back straight pipe on a cummins with a 7 inch tip . it looks awesome but sounds even awesome-r

[hd01chevy]

ChevyBoy any way i can get a sound clip of what it sounds like.thanks

[hockeypro1411]

I have true dual 3" straight pipes into 4" tips. I didn't notice any power loss versus open headers or Flowmaster Super 44's.