Un-muffled 6.2

[Tanner]

I think it is much faster now that I have mufflers and full exhaust on it.

Ahhh yes.... the 'Levi's dyno' comes into play here. I have yet to see anyone from my walk in life that has compared before/after HP/TQ results on their truck when going from factory exhaust to red-neck... errr,.... hot rod exhaust.

'Tanner'

 

[Tanner]

Minimal improvement, the exhaust is already dual and more than sufficient for naturally aspirated.

Turbocharged trucks can get by without a muffler because the turbine absorbs the sonic energy and converts it to mechanical energy which then goes to compressing the intake air.. Temperature also drops over the turbine which also reduces losses through the muffler.

If the sonic energy theory is true, then a loud, unmuffled diesel should run like a cat shot in the a$$ with a bazooka.

Temp drops over the turbine? Okay, how do hot compressed exhaust gasses drop in temp? I was evidently sleeping through Physics class...

 

[Cucvnut]

I hate my mufflers but i leave them on untill i can weld on my dynomax mufflers

 

[Sharecropper]

patracy, I bet that thang sounds good going up Racoon Mountain!

 

[Keith_J]

If the sonic energy theory is true, then a loud, unmuffled diesel should run like a cat shot in the a$$ with a bazooka.

Temp drops over the turbine? Okay, how do hot compressed exhaust gasses drop in temp? I was evidently sleeping through Physics class...

Sonic energy is the non-uniform pressure. These pulses in the exhaust manifold upstream of a turbocharger ARE a significant part of the total enthalpy (that is energy) which is extracted by the turbine. Heat and pressure, the "sonic" moniker distinguishes this as dynamic pressure, rather than static pressure most are familiar with.

This is why a turbocharger adds power without significant increase in back pressure. The rather low specific output (155 BHP) from 379 cubic inches and dual exhaust means performance isn't hampered by the mufflers. The total mass flow through the engine is also low due to the low engine speed (3600 RPM).

 

[wreckerman893]

So basicly anyone with a stock deuce falls into that category...

The deuces with turbos are not as loud as a straight pipe. In Alabama a turbo qualifies as a muffling device. When I built my bobber I split the exhaust into a duel stack set up and it quieted it down considerably.

I have a NA M275 tractor and I installed a better muffler on it than was on it when I got it. Twenty minutes in it before the new muffler would give me a headache even with hearing protectors.

Making noise for noises sake is rude and makes a bad impression to those outside the hobby.

 

[rbeasley66]

[media]http://www.youtube.com/watch?v=NT6DCjsy-BM&feature=plcp[/media]

When I built my bobber I split the exhaust into a duel stack set up and it quieted it down considerably.

Seems to me i am kin to someone that is driving that bobber around wreckerman.
This thread is usless without "SOUND"

 

[wreckerman893]

See.......nice mellow whistler sound.

 

[wayne pick]

There are two performance advantages to the straight pipe on my truck. The turbo spins up faster and the EGT are 200 degrees lower when going up steep grades and it has a real cool turbo whistle to it. It also discourages tailgaters as I boot the throttle and give em a soot shower. As far as noise goes, it's no louder than the raspy straight piped harleys, buzz box rice burner civics or 8in piped jake braked semi rigs arround here. I could really give a flying crap about how loud it is.

 

[patracy]

Ahhh yes.... the 'Levi's dyno' comes into play here. I have yet to see anyone from my walk in life that has compared before/after HP/TQ results on their truck when going from factory exhaust to red-neck... errr,.... hot rod exhaust.

'Tanner'

Tanner, go back and read his post. He thinks he has more power after he installed an exhaust instead of how it was running before with a "open" exhaust.

Sonic energy is the non-uniform pressure. These pulses in the exhaust manifold upstream of a turbocharger ARE a significant part of the total enthalpy (that is energy) which is extracted by the turbine. Heat and pressure, the "sonic" moniker distinguishes this as dynamic pressure, rather than static pressure most are familiar with.

This is why a turbocharger adds power without significant increase in back pressure. The rather low specific output (155 BHP) from 379 cubic inches and dual exhaust means performance isn't hampered by the mufflers. The total mass flow through the engine is also low due to the low engine speed (3600 RPM).

I'm not sure where you're getting this sonic energy stuff at. Everything I've ever been taught or studied is about the thermal conversion of exhaust energy back to kinetic energy. Sonic energy doesn't have enough potential to move the turbine.

Also you're wrong about the increase in backpressure. As you near the end of a turbo's map, the drive pressure hits and exceeds 1:1. Here's a video of my own truck. The 0-100psi gauge to the left is drive pressure (tapped pre turbo into the exhaust manifold). And the 0-60psi gauge on the right is boost pressure. Notice as I near the 45psi mark. (End of the effective map of the turbo) Pressures match.

[media]http://www.youtube.com/watch?v=G018zl9U-JY[/media]

There's NO way the rest of the exhaust can be any factor in this either. As once the exhaust passes the turbine it's dumped out into a 5" exhaust. No muffler and straight for the most part except for the bend over the rear axle.

The reason turbocharging works so efficiently is due to the fact they convert thermal energy back to kinetic energy. They do this conversion efficiently and without a physical connection to the engine. Approximately 1/3 of the energy of fuel in a ICE is wasted as heat out the exhaust.

 

[twomorestrokes]

Wasn't my truck. But I have had a gas engine without mufflers once. I had straight pipe running from the headers back to the bumper. I drove around the block ONE time and came back to cut the pipes and install mufflers.

FWIW, my 1008 is turbo'ed and I have a 3" glasspack muffler as well. My dodge has a 5" straight pipe (Cummins diesel), and it's annoying.

Oops, my mistake patracy. The truck in the video in question DID have mufflers on it. Sorry. I thought it was quiet for an uncorked diesel.

[media]http://www.youtube.com/watch?v=hPXVO6Bdync[/media]

 

[BigRix]

Let me be clear. I don't know for sure if it has more power with full exhaust or not. I know the vehicle drives faster now because I can actually drive at full throttle. It was so loud before that I just pussy footed around town. One, I didn't like the sound and two, I didn't want any extra attention from the boys in blue.

In high school. I would have loved the cherry bomb sound. Now, not so much.

It's too loud or I'm too old. Maybe both.

 

[dstang97]

No real gains in performance on a 6.2 - you hit a point of diminishing returns. And to let you know - the 40 hp increase injectors are a myth. I'll save you some time...

'Tanner'

Yeah save your money for the 200hp ones.

 

[twomorestrokes]

Yeah save your money for the 200hp ones.

 

[Blue2actual]

my 6.5 TD is running a 3 inch straight pipe. it's not loud all. Turbo makes it have a nice whistle!

 

[Brett09]

I cut off the mufflers before I installed a banks turbo on my m1008 just to see what it would sound like. I think I'd rather drive a riced up civic with the muffler plumbed into the cab. It was truly the worst thing I've ever heard. I still have nightmares.

 

[rhinob]

Is there a similar device that converts BS into fact? (other than the Internet)

Haha....that's funny. BUT, with certain aircraft they used 'augmenters' to take the straight pipes into a can-type configuration that supposedly adds a tiny bit of thrust. Early C-310's have such a setup. I've not studied this as an engineer, but have heard this from several different credible sources.

However, I will not be doing this to my M1009. It's already loud enough.

 

[SouthernSteel]

My m1008 the red one had holes cut in the bed and the exhaust was straight piped up into the bed u could see my tailpipes in the rearview. When the thing got warm it sounded great lol when it high idled that was annoying and freaking loud so i bought prebent tailpipes and some mufflers from advance autoparts and been happy ever sense Driving down the road was freaking ridiculous to say the least u couldnt hear yourself think with it straight piped

BTW im young to im only 33 i value my hearing and i enjoy driving my m1008 more lol


twomorestrokes im glad i couldhelp :] it took it away when i edited the post

 

[twomorestrokes]

I cut off the mufflers before I installed a banks turbo on my m1008 just to see what it would sound like. I think I'd rather drive a riced up civic with the muffler plumbed into the cab. It was truly the worst thing I've ever heard. I still have nightmares.

Hahaha! Thanks for that. Anyone know if you can get a front crossover setup for the 6.2 that is meant to feed into a larger diameter single pipe?

 

[robert c neth]

diesels in pa dont require mufflers .my kid and all his friends have them removed and they are not that loud.i geuss it depands on where you live .i live next to i 90 and there are way more annoying vehicles than a 62 or 6.5 without mufflers.