new and thinking of taking the leap for a duramax

[ericnottelin]

Hello everyone,

My name is Eric and I currently own a 2008 Chevy vortex max (6.0L) Silverado.

I found a 07.5 GMC truck just like my current truck but in the 2500 range with the duramax. It is an SLE (leather) crew cab short bed truck. The truck has 93k miles on it and They are asking $33.5k. I am offering somewhere in the neighborhood of $28k.

I tow a 9k toy hauler.

So that is a little about me.

I would welcome any thoughts or suggestions before i purchase it (assuming the dealer comes down on the price).

I am thinking of doing the EGR and DPF delete. I got a price quote for $1500 for the above which also includes a 5" exhaust w/ EFI live and a cts monitor.

Again any thoughts on pricing for the truck, upgrades (worth it or not), and anything else you think is important for me to know.

I drive like an old lady. I currently get 13-14 mpg average with my gasser and towing I get 8-9mph. Would love to increase this, especially with the higher fuel cost for diesel, just to so the higher cost of diesel is offset by the higher mpg.

Thanks guys in advance.

Eric

 

[xtremebikr04]

Welcome! Hard to beat the dmax!:thumb:

 

[duramaxdiesel]

Hi Eric,

You'll wonder why it took you so long to get out of your gasser Trust me, get rid of the EGR and DPF. I did and it is a night and day difference.

Welcome to the site:thumb:


Nick

 

[Poltergeist]

:welcome2:

 

[ericnottelin]

Wow guys thanks for the fast response.

As I am browsing through y'all 's site, I getting different opinions of leaving the exhaust stock or going to a larger diameter exhaust. I am not into loud. I just want a nice diesel sound that will not drive my young family nuts on loooonnnngggg road trips while pulling the camper. Should I stick with the stock exhaust and just do the DPF and EGR delete with tune?? Again, just looking to increase MPGs over stock and towing ability. I WILL NOT BE RACING!!!

 

[Gone Nomad]

...I am not into loud. I just want a nice diesel sound that will not drive my young family nuts on loooonnnngggg road trips while pulling the camper. Should I stick with the stock exhaust and just do the DPF and EGR delete with tune?? Again, just looking to increase MPGs over stock and towing ability. I WILL NOT BE RACING!!!

Once those two flow impediments (DOC & DPF) are no longer there, there should be very little (if any) lightly loaded cruise fuel economy gain by going from 3.5" to 4" exhaust.
Towing very heavy up hills all day, 4" would make a small difference, but only if the load is heavy and the hills are steep.

One problem you may have is 4" tubing is more commonly available than 3.5" and most muffler shops have no dies to bend 3.5" either. You may be able to find a used LB7 front pipe (no DOC or DPF) for around $50 or less, but if not, what may be the easiest way is to use a 4" aftermarket front pipe like this one and then transition down to 3.5" ahead of the stock muffler.
Working with your oem front pipe (i.e.: removing those extra components) is a PITA but you may want to retain the "totally stock" look, depending on your local regulations.

Among aftermarket mufflers, the 8" round mufflers at the bottom of this page are pretty quiet. I think the mufflers included with most aftermarket exhaust systems are louder than those.


Note: I've used the term "front pipe" to refer to what many others call a "down pipe" because on a DMax there is another pipe that comes down from the turbo (sometimes called a "turbo direct" pipe).

 

[NinjaMax]

Go to a 5" and use a borg warner muffler

 

[ericnottelin]

Go to a 5" and use a turbo as your muffler

I think that would negate my previous comment about not wanting to drive my wife nuts on long road trips...

 

[NinjaMax]

Lol...that whistle is soothing..

 

[ericnottelin]

Once those two flow impediments (DOC & DPF) are no longer there, there should be very little (if any) lightly loaded cruise fuel economy gain by going from 3.5" to 4" exhaust.
Towing very heavy up hills all day, 4" would make a small difference. Only problem you may have is 4" tubing is more commonly available than 3.5" and most muffler shops have no dies to bend 3.5" either. You may be able to find a used LB7 front pipe (no DOC or DPF) for around $50 or less, but if not, what may be the easiest way is to use a 4" aftermarket front pipe like this one and then transition down to 3.5" ahead of the stock muffler.
...

Ok, I'm new at this, so please don't beat me up to bad.

So your saying to save the money and keep the stock exhaust and just do the DPF delete with the part you suggested? I am talking with a guy from dieselautopower.com who I was referred to by a friend that had good luck with them. The guy seemed knowledgeable but at the end of the day, they are salesmen and I don't want to spend money needlessly. When they were pricing out everything, they said I could go to either a 4 or 5 inch exhaust that contained the DPF delete. They suggested a 5 inch as I was more concerned with a milder tone for $368.00.

Again, I appreciate your thoughts

 

[Gone Nomad]

Ok, I'm new at this, so please don't beat me up to bad.

Well, don't feel bad. I have people try to do that to me all the time, for posting factual data and test results. You'd be astonished at the examples I could cite.
I've never understood why so many people on these forums act like a drag race or a dyno test is should be judged like a popularity contest or a beauty pageant, but it is what it is.

So your saying to save the money and keep the stock exhaust and just do the DPF delete with the part you suggested?

Yes. No doubt about that. And it doesn't matter how many others post opinions to the contrary. If you want to get the most bang for the buck, that's the way to go. If you stumble across a good LB7 front pipe for $20, use that. If you have to pay $50 for an LB7 pipe, it starts to weigh in favor of that $73 DiamondEye 4" front pipe, mainly because it gains you flow on that first bend where the exhaust gases coming down from the turbo are still the hottest (and thus, the most volume). As the exhaust cools down some, especially aft of the muffler, there is less need for as large of a pipe.

I am talking with a guy from dieselautopower.com who I was referred to by a friend that had good luck with them. The guy seemed knowledgeable but at the end of the day, they are salesmen...

...which is a very important point to keep in mind. They lurk on forums like this too.

I don't want to spend money needlessly.

Me either. A lot of guys on forums like these have a different outlook though.

...they said I could go to either a 4 or 5 inch exhaust that contained the DPF delete. They suggested a 5 inch as I was more concerned with a milder tone for $368.00.

They suggested 5" in order to HAVE a milder tone? Well, no...
All else equal, a larger exhaust will be noisier. In fact, if you used one of the 4" Flo-pro mufflers at the link above, it would be quieter with the oem 3.5" tailpipe than with an aftermarket 4" taipipe.
The only way a 5" system is quieter is if it has a different, quieter muffler than the 4" system, and that's usually not the case.

Also, a 5" exhaust is overkill for a DMax with under 400hp (and probably if under 500hp). For instance, GM stayed with 3.5" pipe on the 397hp LML.

BTW, most aftermarket tailpipes are two-piece. ANSA Silverline is an exception.
...

 

[ericnottelin]

Great thanks. I did discover that the part you suggested was for the older style. Mine will be the 2007.5 and greater (I believe it is the LMM). I wonder if my local muffler shop can do it for me without ordering the part

 

[ericnottelin]

That was what the guy told me. A flopro 5" kit would be quieter than the 4" kit. Something about the tone.

 

[ericnottelin]

I found this pipe aFe Atlas Exhaust Kit DPF Delete Pipe GM Duramax 07.5-10 LMM EC/SB (AL)

Wasn't sure if I could do hyper links. This seems like it would be a direct bolt in for the stock exhaust. It is $179.00. So about a $200 savings if I am looking at this right and I would just keep the stock exhaust and muffler

 

[Gone Nomad]

Great thanks. I did discover that the part you suggested was for the older style. Mine will be the 2007.5 and greater (I believe it is the LMM).

If you're talking about this DiamondEye pipe:

...the only reason it might technically be only for older than 2007.5 is because it has no provision for a DPF.
The actual fit is all the same from 2002-2010.
The one at the link above is 409 Stainless Steel (at least that's what the part number indicates).
When you see "(AL)" that usually means it's aluminized mild steel, which means it will eventually rust out.
Your stock exhaust is some form of stainless steel (supposedly 409), and it does rust, but mostly just surface rust.

I wonder if my local muffler shop can do it for me without ordering the part

They probably can if they can bend 4" pipe but the result probably will cost more than buying a manufactured pipe because they'd have to weld on a flange on the front end to mate up with the turbo downpipe, via a V-band clamp. This kind of stuff is outside the realm of what run-of-the-mill muffler shops do, although if you provide them with a flange, I'm sure their welder could put it all together. Most of them use mild steel wire in their MIG welders, so that's another source of rust. That's why a manufactured SS front pipe is the way to go, if you want longevity.

 

[Gone Nomad]

I found this pipe aFe Atlas Exhaust Kit DPF Delete Pipe GM Duramax 07.5-10 LMM EC/SB (AL)

Wasn't sure if I could do hyper links. This seems like it would be a direct bolt in for the stock exhaust. It is $179.00. So about a $200 savings if I am looking at this right and I would just keep the stock exhaust and muffler

That's a DPF delete pipe. The "(AL)" means it's aluminized steel rather than stainless steel. The 4-bolt flange is the front; the 3-bolt flange is the rear (muffler side).
It replaces the section between the front pipe and the muffler, and it leaves the DOC in place. Replacing the front pipe allows you to eliminate that restriction and also the extra bends that associated with the DOC:

You could use the DPF delete pipe if you were doing it all yourself, since it's all bolt-on (after you get the rusty nuts to break free).
But it may be more expensive than the solution I outlined (although maybe not if you replace it yourself vs. having some work done at a muffler shop).
The advantage is that you can take that pipe back off yourself, and put the oem DPF section back in place; a lot of people do this because they want to be able to revert back to stock every year or two.

Since the pickups have a bend in that area (as you can see on the pipe above) to clear a crossmember,
what you would do with the other pipe (the front pipe) is mate up to the existing 3.5" pipe just behind where the DPF is. The 3-bolt flange at the muffler would not need to be taken apart, because a muffler shop would weld it together in place. They'd squeeze the 4" pipe down the a little, and swell out the existing 3.5" pipe a little to put them together (if you used a 4" front pipe rather than an LB7 front pipe).

The main thing to remember is that the fit is the same for all of these, except for the overall length for different cab & bed combinations.
The HD pickup chassis is the same from 2002-2010. Even the 2011+ are not all that different in terms of how these exhaust pipes fit.

One last thing (you've probably already noticed).
The tailpipe outlet is reduced to under 3" where it enter the "megaphone" tip.
It takes about 2 ft. of pipe to replace that.

 

[Hot COCOAL]

I read this thread, and I'd like to welcome Eric:hello:

While I understand you're not looking to build a "race truck" there are benefits beyond horsepower for most the bolt on mods, if one were so inclined to look from a perspective other than racing, while all work toward making a more efficient and powerful platform.

IDK what the sales guy was smokin, bigger is louder, period...4" is plenty big and can be made quiet, enough...

I understand not wanting to waste money and all, and the options being laid out with piecing together an exhaust are solid, but let's look at the prices for cheap full 4" stock replacement systems, I got mine from diamond eye for $400 delivered to my door, downpipe back 4" w/muffler, I could've got the quiet tone option with a resonator for another $100, but opted out and I'm "ok" with the noise level, although pulling 12k up mountain passes get old, mine is down turned over the axle tho...

Opening up the exhaust system tip to tail like that is good for a bunch of reasons, creating a free flowing path for the exhaust gasses to travel eliminates points of heat concentration, relieves back pressure, moves more volume of gasses and in doing so frees up a few ponies and maybe a few tenths of a gallon of economy. Win win, not to mention opens up the pathway to the turbine so you can hear it spool better
$400

PCV re route:
Gets all the recirculated oily vapors and gasses out of the clean air intake tract for the engine and turbo, both beneficial to the air volume available to the engine for maximum performance, and also saving the intake plenum, runners, and intake valves from oily build up, sludge and gunk.
$65

An egr delete will require some tuning, which I'll wrap back around to, but will also keep out undesirable gunk, oils and soot from the intake system, with the same benefits as the PCV reroute to a greater degree
$350

Tuning
Who doesn't want an extra 130whp?
Just cuz it's there doesn't mean it's a race truck, it's just optimized for performance, and the best thing is, you can have more than one tune, so you can have tunes for every occasion, known as DSP5 efi live tuning, I'd suggest getting set up with a switch, an auto cal and stock trans tuning
$700

Trans go jr
For the transmission, needed to help shorten the shift event and increase line pressure for added power holding potential
$95

There $1610 is what you'd need to spend to have a ripper of a street truck that can do everything it was intended to from the factory and more, while attaining better fuel economy at the same time, well, that is if you can stay out of the boost

The best thing is...Everyone of these mods can be done in your garage in a couple hours or less

That's a pretty sweet deal if ya ask me, can't be duplicated in any other platform than a turbo diesel like these modern trucks from the big three, you can't get the power increase for the same amount of cash anyways, step up for more power than this set up offers tho, and it's gets expensive in a hurry



:thumb:

 

[Hot COCOAL]

Let's not forget available discounts...

As they say, you gotta pay to play...
But, becoming a member of the NHRDA (National Hot Rod Diesel Association) costs $75 but has perks such as discounts on tons of merchandise, you may want to look into that as well, sometimes they have special offers with merchants that discount $150 or more off exhaust systems and there are other parts too.

Just somethin to think about:angel:

 

[bigjohn]

Welcome !

 

[ericnottelin]

Sorry guys, I worked all day and was losing the battle for sleep last night.

Thanks again for all the advice. The exhaust info has been very helpful. At least I have a lot more info to make an informed decision. I can't thank you guys enough...

The PVC thing is new and I will have to research how to do this.

Now I am also planning on doing the EGR delete. I have noticed that some guys said they just installed a blocking plate. Is this the same thing as the EGR delete kit or is it a more simple mod that does the exact same thing. The EGR delete kit is $130.00. They said it is a little work but can be done in a few hours. What is the benefit / downside of doing the blocking plate (if different from the "kit") vs the traditional kit.

I do plan on doing the EFI live with CTS. Cost $$$ but the sales guy said I would be able to adjust tunes on the fly. I was told I would have five tunes from 40 -100 hp gains. They told me to play with different tunes to see what ones I liked and which ones provided the best MPGs.

I was told I didn't need the trans tuner as I was staying under 100hp. I have had a truck with a shift kit in it and that was way to jerky.

Again guys, thanks again. I sure hope all these questions and answers in one place helps someone else out as well.