Had a straight pipe put in place of the muffler today, sounds like a baby semi...haha, can faintly hear the turbo whistle through the exhaust and get a nice resonance at about 2700, interesting. Seems to pull mildly harder in the top end and same on bottom end *shrugs*, full throttle even with the windows down the engine is quieter, also when steady cruising it is quieter in the cab with windows down than it used to be.

But man does it growl when you nail it http://www.dieselplace.com/forum/smileys/Clap.gif

well as much as a stock duramax can growl...haha, wonder how restrictive that stock muffler is anyhow, looked the gases had to make two 180 turns inside based on the layout.

What size "pipe" is the replacement pipe size? My local exhaust shops say they only have 3 inch pipe....http://www.dieselplace.com/forum/smileys/Ermm.gif Would this still be ok?

Thats what they used for mine, you canhardly tell, I figure if I didn't like it I could always go with one of the aftermarket setups. Besides, even a 2.5 inch pipe would likely still flow better than the factory muffler.

cool,


They want $50.00, you'd say that's worth it just for the sound?

Our trucks use 3-1/2"
Most exhaust shops stop at 3".

The shop I took mine to also could not handle 3-1/2 but he ordered a piece anyway. We were able to "bellmouth" the ends with his expander and he just welded it up. The bellmouth helped compensate for the misalignment of the two ends.

Kinda like this......

http://www.uscom.com/~hoot/cars/duramax/gmc/exhaust/Picture3.jpgEdited by: hoot

Thanks guys,


I'm going tomorrow..........

Thats exactly what I want, but I've been to two shops that can't/won't do it.http://www.dieselplace.com/forum/smileys/Unhappy.gif One shop said that even if they would, that I would hate it because it would be way too loud...


I think they're FOS.


Did you guys use a stainless piece?


Mike

aluminized, it is very quiet, sounds like a UPS truck.

aluminized, it is very quiet, sounds like a UPS truck.

Mine is aluminized.

Quite? http://www.dieselplace.com/forum/smileys/Pinch.gif

yes, mine is pretty quiet, nowhere near as loud as my PSD was, might be due to the tailpiep angled to the rear, so all the sound is going away, and the PSD was direct sideways.

I dropped my truck off this morning for the straight pipe. I have the original 3.5" tailpipe from my 2001 6.0L and I told the muffler shop to cut it and use for my straight pipe. We shall see if he actually understood my english. Total cost is supposed to be $45.http://www.dieselplace.com/forum/smileys/Cool.gif

Got my truck back at lunch. The install looks sweet! They took my old 3.5" oem tail pipe (from 2001 6.0L) and cut two pieces that made lovely swooping "s" shape that fit the oem muffler's place perfectly.

As for you p*ssy's http://www.dieselplace.com/forum/smileys/Wink.gif that think straight piped is loud, you need to go listen to a 6.0L with a Flowmaster 70 series muffler. This thing is quieter than the quietest aftermarket exhaust (gassers) that I have heard. I am actually a little disappointed, I expected it to be as loud as my 1994 350 with glass packs. http://www.dieselplace.com/forum/smileys/Ermm.gif http://www.dieselplace.com/forum/smileys/Wink.gif

I imagine the turbo takes a lot of the bark out of it. cdhd2001, do you have a Cat? I am sure the cat would quiet it down as much or more then the muffler.

No cats here in Texas. (Well maybe, but I tend to shoot strays.)http://www.dieselplace.com/forum/smileys/Embarrased.gif

I got mine back today as well. I loved the ride home http://www.dieselplace.com/forum/smileys/Big Smile.gif I was hoping for some turbo whine like you can get with the Furd's 6.0, but the tone was exactly like I was wanting. Found a place that had 4" and it slid right over the stock pipe. $10.00 cheaper than they had quoted....http://www.dieselplace.com/forum/smileys/Clap.gifBest (cheapest) mod I've done with no remorse.http://www.dieselplace.com/forum/smileys/Embarrased.gif

My friend had his 01 dmax straight piped, and I thought it was much louder than my PSD. It really "rapped out" in the higher rpm ranges... I liked ithttp://www.dieselplace.com/forum/smileys/Cool.gif... his wife didn'thttp://www.dieselplace.com/forum/smileys/Ermm.gif


Mike

Well, I did it also, got "piped" today. It was a chore finding the 3.5" stock, but I ran across a supplier today and snatched up a piece. He also had some FPPF Total Power that I picked up.


I purchased a 3' section of Aluminized for $15. Had the installer flare the ends, cut the OEM muffler out and welded in the piece after a bit of trimming. Labor costs - $30. Total cost..... $45 http://www.dieselplace.com/forum/smileys/Clap.gif


My impressions -


At idle no discernable difference.. accellerate away at a casual pace and you can notice a lower rumble. Rolled the windows down in traffic, sounds like a deep aftermarket exhaust on a gasser, with the usual diesel inflections.


But... when you romp on it http://www.dieselplace.com/forum/smileys/Wacko.gif .. hard to describe, but the phrase vulgar obscene mutant Freightliner comes to mind. It sounds like what I suppose open headers on a Diesel would sound like, "rapped out" as Dieselman84 calls it fits. No regrets, I'd bet performance and EGT reduction-wise it's as good or better than a 4" system. Not for everyone, but I'm quite satisfied.





Mike

Maybe I have been on the flightline too long, but I don't find it loud at all...

You guys need to here a straight piped dmax towing a 5th wheel. Accelerating at a decent pace makes people turn their heads 2 blocks away! Just not loud enough to break windows!http://www.dieselplace.com/forum/smileys/Clown.gif

cd-


That is my main concern...towing straight piped. Had thought about doing the straight pipe as well (instead of 4" system), more for EGT reduction than anything...ok maybe some more rumble!!!


But am concerned about the "noise" from the passenger seat if the exhaust note is intrusive while towing. She was just commenting on how quiet it is the other day... http://www.dieselplace.com/forum/smileys/Disapprove.gif


Bob

With the windows rolled up you barely hear a rumble in the cab. It is only loud when you have the windows rolled down going up a 6% grade. BTW, my wife loves the sound our straight piped dmax!http://www.dieselplace.com/forum/smileys/Embarrased.gif http://www.dieselplace.com/forum/smileys/Cool.gif

I'd like to hear one in person. I haven't heard too many piped Dmaxs of any kind in my area. I too have concerns towing. My straight piped 350 was fun until the second hour towing my enclosed sled trailer. I know gas to diesel is different. We need someone to fashion a kit. It can't be too hard.

What I like to know is, do you get any noticable power from the straight pipe mod. http://www.dieselplace.com/forum/smileys/Cool.gif





2001 Dmax 24000 mi Edited by: easymon4u

No noticable difference here.

If any of you think a DMAX is loud when straight piped, you don't remember your 6.5's very well, when they were straight piped,,,huh, whats that you said? http://www.dieselplace.com/forum/smileys/Big Smile.gif

I have a new 4" system on the way to my doorstep as I type this. I was wondering, how would the exhaust sound if I installed the muffler "backwards", with the louvers facing the rear of the truck instead of the front? I want a good deep rumble, but I'm a little concerned that straight pipes might be too loud.


Kevinhttp://www.dieselplace.com/forum/smileys/Cool.gifEdited by: Fireman

Ok, for you guys that have had it on for a while, is there any difference in mileage? This one has a cat, so I figure it wouldn't be too loud. Is there anybody who makes a kit or something so I could just do this at home? Would like to get stainless steel. I am a fairly decent welder, and have access to one, so I hope to do it in the garage and save the labor costs.

No milage or power diffence for me but I didnt have stock exhaust. I could also roll a grapefruit through my other muffler so it was not restrictivehttp://www.dieselplace.com/forum/smileys/Approve.gif Gained some sound thoughhttp://www.dieselplace.com/forum/smileys/Cool.gif

I found this one already made up $70.00 + Shipping.
http://www.exhaustproslinc.com/

NICE! (http://www.exhaustproslinc.com/mufreppip.html)

Their you go puttin more good stuff on here to make me want it. Its's workin too! Only problem is my xmas money is spent for the next 2 years already http://www.dieselplace.com/forum/smileys/Embarrased.gif

[QUOTE=easymon4u]I found this one already made up $70.00 + Shipping.
http://www.exhaustproslinc.com/[/QUOTE (http://www.exhaustproslinc.com//QUOTE)]


easymon4u. Does replacing the muffer with a straight pipe do anything for performance? How much louder is it? thanks.

I straight piped my Banks 4", I could only take it for a week or so. The first time I towed with it was it. Way too loud!! Muffler is back on, I didn't notice any difference in egt's either.

John

Mine's been straight piped for a couple years now.

I was actually looking for someone to mandrel bend aluminized pipe, I was going to offer the same thing! I can get the aluminized stock and have the ends flared and offer that cheap, its the bending I can't find someone to do. He's making a few bucks for sure at $70, but I can't fault him for that, it's a great option and having the clamps makes it a simple install (mine's welded).


Mike

Lakedaisy...
It is louder, but I really can't say if more power is being made. Maybe, some restictive weight sure has been dropped.

Same vendor, lower price.


Buy it now for $49.95 & $10.00 to ship. 6 available.


http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2451372224&category=33 633&rd=1

I see that.... Hummm

I wonder how good they fit.. It's not Chevy specific according to the description.

Camstyn,


I questioned them on this issue. If you purchase one of them, you tell them which truck you need it for and they send you the correct pipe. Below is the link to their website. The muffler eliminator pipes have different part numbers, but they could still all be the same part.http://www.dieselplace.com/forum/smileys/Confused.gif


http://www.exhaustproslinc.com/index.html

I wonder how good they fit.. It's not Chevy specific according to the description.

I had mine welded on and it had to be trimmed about 1" on each side. I guess it would depend on where you cut the muffler. I like it's sound. You can install this with just the clamps, and I would loosen the pipe hangers to fit with out to much trouble. Thats why the place that welded mine had to trim the part to get it fitted, he did not loosen the hangers. Get a good sawsall blade and go for it. "Man I need a transgo kit now, and some new rubber". Come on W-2 forms. Edited by: easymon4u

is straight piped legal? We have anal retentive bears around our local area. Does the egt really go down ? I am looking to put the temp stuff in like a few of you guys suggested and now with this straight pipe idea it sure sounds better than 700 bucks for a 4" exhaust sys. again thanx for the idea and infohttp://www.dieselplace.com/forum/smileys/Clap.gif Edited by: AkDually61

I suggest you check with a local muffler shop and see what they think. It's really not that loud and it will help your air flow.

I wonder how good they fit.. It's not Chevy specific according to the description.

I had mine welded on and it had to be trimmed about 1" on each side. I guess it would depend on where you cut the muffler. I like it's sound. You can install this with just the clamps, and I would loosen the pipe hangers to fit with out to much trouble. Thats why the place that welded mine had to trim the part to get it fitted, he did not loosen the hangers. Get a good sawsall blade and go for it. "Man I need a transgo kit now, and some new rubber". Come on W-2 forms.





If you use clamps, does it permit you to put the muffler back on if its too loud or Johnny Law catches you with it? Do they supply the clamps with this kit?

I just installed my straight pipe from www.exhaustproslinc.com (http://www.exhaustproslinc.com) last night.....It took longer to plug in my sawzall.


Amazing sound, kinda loud though for the neighborhood if you nail it.

I have a neighbor that seems to mention it often. I lighten up on the pedal going through residential neighborhoods. At least it's not as loud as my horn. http://www.dieselplace.com/forum/smileys/HiHi.gif

http://www.dieselplace.com/forum/uploads/762_DSCN4929.jpgEdited by: hoot

Hoot, are those flutes for real??

Yep

So as not to highjack this thread, read more here....



horns (http://www.dieselplace.com/forum/forum_posts.asp?TID=4851&PN=3)Edited by: hoot

Hoot,


I'm a finite element analyst by trade and I was curious as to what package your previous graphic is from... FEA, solid modeler, CNC software? Do you do design work?


Mike

Hoot,


I'm a finite element analyst by trade and I was curious as to what package your previous graphic is from... FEA, solid modeler, CNC software? Do you do design work?


Mike

Mike,

It's CATIA V4. CAD/CAM and everything else in one package. It's in highest category of design software available. It's the software Boeing used to design the 777. Also Chrysler, Lockheed Martin and Airbus use it. I'm a CNC programmer. I use CATIA to do programming and some tool design work.

Mike

Edited by: hoot

http://www.dieselplace.com/forum/smileys/Big Smile.gifHad a straight pipe installed in place of the huge muffler. I have 2300 miles on my DMax and now I like the sound coming out of the tailpipe. The turbo and CAT muffle the noise just enough to make it sound like a baby big rig. I can't wait to take it out and climb the hills on the way to the left coast. I took it to a reputable muffler shop here in Fresno. $5 a foot for the 3 1/2 stainless and $45 dollars labor for the cuts and bends to match it up. I am a happy camper. I am keeping the muffler around just in case uncle sam decides to start inspecting exhaust systems for some reason.

Has anyone compared a straight piped truck to one with a straight through muffler? I was thinking I might want to buy one and now I wondering if it's just a total waste of money.


Also it would be nice to hear how much EGT improvement that can be expected. I know it's kinda hard to nail down the numbers but any input would help. --SS

aluminized, it is very quiet, sounds like a UPS truck.


Shoot..The International T444E in my UPS truck is one loud SOB!!! I get told by my customers all the time that they could hear me coming....LOL!!! Who needs a horn!!!! http://www.dieselplace.com/forum/smileys/Cool.gif


I can see why Furds are so damn loud...Powerstucks are International engines. What I can't figure is why, then, are they so unreliable? See my sig to see why I ask.