Exhaust upgrade?

[Dmaxin]

I have been looking to upgrade the stock exhaust and was wondering if one system was any better than the other? I have looked at a few differant ones and am just really unsure. Also does just that half inch increase in pipe dia. really make much of an improvement in power.

[IndigoDually]

I too am trying to decide what to do with the stock exhaust. Upgrading the exhaust is only part of the equation. Only installing a bigger exhaust may not show much performance improvement, it should lower EGT's some though. A larger exhaust will make an difference when adding intake improvements (like an Amsoil Air filter) and installing a box (Juice, etc.). The factory system works well for the stock performance, changing the muffler and tailpipe will help it some though.
So You really have to decide how far You intend to go. I for one am going to ditch the factory muffler and tailpipe and go from there. I'll probably go with a 4" muffler and pipe for now until I jump into a Box of some kind.

John

[Silver Bullet]

DMaxin,
I talked to several people (TDP and local muffler shop) before deciding just to upgrade the muffler. The conclusion I came to was...since I am not towing a lot a weight I could not justify the extra expense of a full 4" system. If I was towing more then the full 4" system would help with a little more flow and lower temps. The muffler has a 4" center, so if I decide to put on a 4" system I can reuse the muffler. The Dynomax I put on sounds good, but not exactly what I was hoping for. I really want to hear a straight pipe!

On edit:
I put on my K&N Air Charger at the same time and I like hearing the turbo whistle more than hearing the exhaust!!! :D I drive around with PS front window cracked just to hear it sing!!! The whistle is louder and it spools up quicker.

[ 11-08-2002: Message edited by: Silver Bullet ]</p>

[MaxRock]

Hey SB, when are you going to cut out that muffler and straight pipe your rig??? Enquiring minds want to know!!!!!

MaxRock

[DMAXDiva]

SB:

If you value your relationship with your neighbors, you may not want to straight-pipe your truck. I know, I know...it's all a matter of personal preference, but a straight is WAY-loud, epecially under acceleration...but if you really want to do it, I still have about 5 feet of stainless 3.5" pipe left from when I went temporarily insane and straight-piped my truck tongue.gif ...let me know if you're interested (you can always slap the muffler back on...)

[ 11-08-2002: Message edited by: DMAXDiva ]

[ 11-11-2002: Message edited by: DMAXDiva ]</p>

[Reno DMAX]

Me too!

I'm interested in changing out the restrictive muffler and would welcome any recommendations. smile.gif

[Steve Joneli]

I put the Kennedy 3 1/2 inch system on my truck. installation was straight forward and easy (for an exhaust) everything fit right. It sounds good and really helped the fuel economy and power. I would do it again.

[YZF1R]

I also have the Kennedy system and love it! By the way, the Kennedy system is 4 inch.

Steve

On edit: Opps, sorry Steve. Didn't see what truck you have.

[ 11-09-2002: Message edited by: YZF1R ]</p>

[ThePend]

If you go for an exaust upgrade. Look into the Banks system. Right now they are running specials. Give em a call and ask for Tony.

Lloyd

[chevmeister]

anyone on here insane enough to build a 5" system for these trucks?? I was thinking about some mack exhaust....... Maybe even stacks!
It really sucks when your imagination outweighs your CC limits.

[CSDMAX]

Kennedy has a 5" system also. It is a 4" down pipe to the muffler and then 5" from the muffler back.

[gardnerteam]

I too have been investigating for about a year and like Kennedy's 4"/5" system except for the loudness. In a email conversation with him, he "hinted" he might look for something quieter for the longbed CC at least, and for those of us who blew out out eardrums early in the 60's with open headers, no mufflers, and drag strips before we knew what damage we were doing to our hearing. While I am not quite deaf, I have a lot of hearing loss and like a quiet cab without background exhaust. I also want less pipe and muffler restriction. I have always achieved this on past trucks with larger exhaust (usually Banks or sometimes custom) with huge flow through mufflers which really did deaden the sound. Still haven't found that for the D/Max. How about it John, any more thoughts on a quieter muffler for your systems for the geritol crowd?

[chevmeister]

well stacks would solve the noise problem. Move the exhaust noise up!

[ 11-10-2002: Message edited by: chevmeister ]</p>

[Kennedy]

gardnerteam,

Many have caught me out in the truck with the forwarding on. I can talk hands free under ANY circumstance. Big Dipper caught us enroute the DP Pull Off III. Elaine was driving, and the microphone is on the driver's side of the OH console. We were towing in the hills of MT at the time.

While I do have an mpeg with audio on my site, I believe that it is a poor representation of the system as it seems louder on the net than it does in person.

As for the 4/5" system, it shouldn't be a problem going about 8" longer on the muffler. Now in THEORY this will mellow it out more, but I have yet to verify. I have a "mega" muffler here, but I'm afraid it is a bit too long to fit without some major trimming to my existing system. There is no doubt that the 4/5 system is louder than the 4" system, it isn't all that bad.

I also had a customer with a short bed insert one of those stubby little Dynomax tin cans in the system ahead of the muffler with good results

Stacks will compound the headache factor by moving the exhaust exit closer to the passenger area. They also make it difficult to install a muffler.

[ 11-10-2002: Message edited by: kennedy ]</p>

[Buck]

I had a chance to get up to Kennedy's Saturday for a look at the operation and got to ride in his truck WOW! :D . Very impressive! The 4/5" exhaust is not near as loud as I thought. It's got a nice sound under FULL power but not annoying at all. Otherwise you can't really hear it. Top notch systems ;)

[Arnie]

Just had John install the 4 in. system, all I can say is WOW..... :D I love the exhaust! John had it on in about 45 minutes, fit perfectly. Sounds great, not to loud just right. It helps the "juiced" Duramax breath now. Thanks again John!! ;)

[HK 3]

For what its worth, I have a 2002 CC with an Edge Juice and K&N Air Inducton Filter. I have installed a 4" MagnaFlow "catback" muffler on the stock 3.5" exhaust. I put the 30" catback muffler because it supposedly would be the quietest muffler. The sound is more aggressive than the stock system, but certainly acceptable. I have had my Duramax idle next to an ATS 5" exhaust system and appreciate the "quieter" sound of the MagnaFlow 4" muffler with the 3.5" exhaust down pipe. I have installed a 4" MagnaFlow Stainless Steel tip which looks great and adds to the aggressive sound, but as stated it is certainly within a decibel range that I think is acceptable. I am not interested in someone hearing me coming from two blocks away.

On the EGT side, I have found that running with a 4.35 Juice with the 90 HP setting and pulling a 6,500 lbs. horse trailer and/or boat up the Parley's grade between Salt Lake City and Park City, Ut, (approximately a 9 mile grade with a 2,400 elevation rise at 80 MPH) that I run at a constant 1,175 to 1,200 EGT, well below the recommended 1,400 EGT max. You can order a galvanized 4" MagnaFlow out of several muffler shops in California for about $165 to $175 and UPS deliver runs about $20. The MgnaFlow 4" SS exhaust tip runs about $80. The only advantage I see in the full 4" catback exhaust systems is lower EGT's. I have found for the loads that I pull up Parley's Canyon, as mentioned above, the stock 3.5" exahust is adequate and the addition of the catback muffler has provided me with a reasonable exhaust sound and EGT ranges that provide excellent power without undue engine tempatures.

[Silver Bullet]

Thanks for the offer Diva...I am going to wait and listen to some other rigs before I do anything to change my existing setup. I don't think I want to go louder, just more diesel sounding!

[imported_]

Is one mandrel bent 4" exaust the same as the next guys 4" exhuast. I know the less bends the better, but does it really make a difference in performance. Everyone has to get from the front of the truck to the back and there is only so many options to do that. Locally prices are ranging from around $600-$1200 can for a down pipe back system. I just can't see one being $600 better then the other.

any suggestion?

[Silver Bullet]

Blue,
You may want to consider the number of pieces...the more pieces means more places to have exhaust leaks unless you get it all welded. In my book fewer pieces is better.

[chuntag95]

Brad,

Yes, there is a difference. Your statement about less bends being better is right on. Think of each bend dragging on the exhaust. The sharper the bend, the worse it is. I won't bore you with the fluid dynamics. Now, the second thing to look at is the material the system is made out of. There is aluminized steel ($3-400 systems), 409 stainless ($575-800), 304 stainless (mufflers on the previous and pipes on the expensive 1000+ systems) and finally 316 stainless steel (for the custom, money just isn't a problem guy we all wish we were). I have listed them increasing in price and quality of material. As you go up the scale, the steel is less likely to rust or turn colors due to heat (oxidation). Now, I will not tell you what to get, BUT consider the elements you drive in up there. Some have aluminized steel and it lasts them as long as they need. The need is different for everyone. It can be measured in miles, time or a combination of both. Read and make an educated decision. :D I think Mac is the steel man and can answer all of the questions on what each steel has for it's alloys and why some will surface rust and others don't. A 1/2 percent of nickel or chrome makes a big difference sometimes.

About as clear as mud again, huh? tongue.gif

[imported_]

hey thanks Chris,

Round and Round. Sometimes to much information is a pain in the a$$. ;) I am going to find out what all the systems are made out of and then do some testing of my own. I have access to some neat salt spray and humidity cabinets. They can be very useful to determine the long term effects of Saskatchewan road salt in the winter. I am also going to paint some of the pipe with some special high heat products (zinc based) I have at my disposal.

BTW, the remote start is working great!! :D :D

[1822]

Put the KD 4" on my 02. Fits like a glove and sounds just right with the muffler turned to the quiet side. Made a big difference in power also.

[Dmaxin]

I have been looking at a lot of exhaust systems and was wondering if the down pipe from the turbo is replaced with these systems? It seems like some systems have the down pipe and some dont. :confused: Also, has anyone heard of or used the Aeroturbine muffler from banks? It sure looks kinda neat. Thanks

[DMAXDiva]

Hi Dmaxin;

When I purchased the Banks system back in June, the company indicated that they would NOT be pursuing a down-pipe from turbo, but spoke with them again in August and they said it was "in the works"... :confused:

All I can say is, when my truck was up on the lift to install the system, I had a chance to eyeball the stock downpipe, and there's not much room there at all! Stocker is wedged pretty tightly against the firewall, so I wonder how anyone can add another .5inch diameter to it...??? I've heard that a few companies have tried it, but have not yet seen one...

[Dmaxin]

DmaxDiva thanks for the quick response. Are you happy with the banks system on your truck? Did you notice any power gains above stock? Thanks again

[chuntag95]

Big Blue,

Post your torture test results. It would be interesting to see what you find out. I don't have to deal with salt much here in Texas, but I do like over engineering. :D

[DMAXDiva]

Dmaxin:

I think the Banks setup is really awesome; install was a cinch, sounds terrific, and EGT's were reduced an average of 150 degrees. Banks claims power gains of 15-20hp, but the truck was never dynoed, so I can't confirm that. Honestly, I think 20hp is really stretchin' it, but then that pesky Juice box has certainly obscured any legitimate perceptions I might have had! tongue.gif

[big dipper]

I guess I am a little late here, but I will fill you in anyway. JK's 4/5 is pretty nice. You really can't hear it much while cruising, but it will let you know when you step on the throttle. Sounds very authorotative in a kind of deep and mellow note. Kind of like having a set of Flowmasters on a big block! No droning noise that some others have complained about. As I said before, very nice!

It looks as if I will be "displaying" the 4/5 at the Ohih Dyno Day if anyone would like to check it out.

[ksss]

Big Dipper,

I have a couple of questions concerning the 4/5. How loud is it in the cab under full acceleration and is it objectionable at that level. I typically have my foot into it and don't want to go deaf(er). Does the 5" exhaust look odd coming out of the pickup? thanks