2008 LMM 6.6 Duramax Aftermarket Exhaust System

(wstr01) · (wstr01) **Join Date: Feb 2001** 05-12-2008, 2:34 PM

Anyone done one of these?

Which brand/system?

Fit and finish?

Noticeable difference in power/mileage (worth the money)?

What other mods with it?

I'm looking for better performance which should mean better mileage.

I think I just want to K&N and exhaust it.

(h20jnky) · (h20jnky) **Join Date: Mar 2003** 05-12-2008, 2:55 PM

i put a dual 4" banks system on my '06 with an AFE stage II cai and no chip.. mileage is better but i only use it to tow? going to powell with 4 adults, 20' VTX and coolers full of food and booze it averaged about 17ish.. you can do plenty of mods to help with economy but towing is relative.. injectors, chips, programmers, batteries, E3 plugs, propane injection, intercoolers, high ram manifolds, exhaust, intake, the list is endless for a diesel.. eBay usually has good deals if you know what to look for.. good luck!

www.bankspower.com
www.mbrp.com
www.afefilters.com

mendo247 05-12-2008, 3:07 PM

www.dieselplace.com

Go here and check their forum on exhaust.

(shane97210) · (shane97210) **Join Date: Jan 2007** 05-12-2008, 3:28 PM

are you talking about a turbo back or filter back? i put a 4" MBRP filter back mainly for looks. did not change sound or mileage. to change mileage you need to remove the dpf and get a programmer that will allow it to run without the dpf and not throw codes. i really want to do the same but am worried about losing my warranty. on the diesel place site there is extensive info about this subject and also the intake. general consensus is the stock intake does just as good or better than most aftermarket. i get 11-12 towing, this new emmisions crap sucks.

(wstr01) · (wstr01) **Join Date: Feb 2001** 05-12-2008, 5:50 PM

Yea, filter back. Guess that answers that question. Still gonna do the K&N cause i get a killer deal on them.

Towing my 23' toyhauler fully loaded up and down grades it was 10mpg this past weekend. The truck only has 1500 miles on it so it may get better with time.

Freeway and around town it's high 18's.

Do not want to mess up my warranty either. Not worth the extra mpg's I may see and it has plenty of power.

(tanner) · (tanner) **Join Date: Oct 2005** 05-12-2008, 6:26 PM

DO NOT PUT A K&N FILTER ON YOUR DURAMAX. You will clog your MAF sensor in no time. Only run dry filters on these trucks. NO OILED FILTERS. GM has actually issued a bulletin about oiled filters.

Honestly I wouldn't waste your money on an aftermarket intake or filter. The stock filter/intake setup actually outflows ALL of the aftermarket units except for one. And the difference between those two is very minor and only noticeable in extreme horsepower set-ups.

(siuski) · (siuski) **Join Date: Feb 2003** 05-13-2008, 6:58 AM

I'll repeat, DO NOT put a K&N on the D/A!

As for your original q, I just put a MBRP 4" DFP back with a muffler delete. I needed to clear a rock guard:

http://www.wakeworld.com/MB/Discus/messages/65921/547051.html

It looks a lot better, but there are no performance gains that I can tell, have heard that it'll drop the egts down 50 deg or so, but I don't have a guage yet. Can hear the whine of the turbo better, but it is not louder. Was easy to install, backed onto a set of ramps and got the original piece out w/o cutting it for future warentee work in needed.

(Message edited by siuski on May 13, 2008)

(jim33) · (jim33) **Join Date: Feb 2008** 05-13-2008, 7:04 AM

Try BullyDog

(tanner) · (tanner) **Join Date: Oct 2005** 05-13-2008, 10:37 AM

If you really want to do something with your mileage, look into a programmer and ditch the DPF like stated earlier. I prefer PPE or EFIlive, but unfortunately GM's ECM now log the last 10 serial #'s of the "program" that was loaded into it. They can cross check this with GM authorized tunes. So now they will know if you have a tuner unless you run an Edge product.

(h20jnky) · (h20jnky) **Join Date: Mar 2003** 05-13-2008, 11:05 AM

knee brace, i know k&n's have had more than a few problems with the oil spreading onto the mass airflow sensor like tanner said, thus ruining it. hopefully you will not have that problem, but i know a few people who have had it happen and warranty did not cover. if warranty coverage is a concern, then dry filter seems like a more logical choice.. just my .02

(wstr01) · (wstr01) **Join Date: Feb 2001** 05-13-2008, 2:50 PM

I ditched the K&N idea.

I guess I'll just leave it stock. I don't trust the dealer to honor the warranty if i start messing with it.

It's still way better than the Sub for pulling, handling while towing and mileage so screw it.

Maybe someone will come to their senses and make diesel prices comparable with gasoline. The truckers have to really be feeling the pain (which in turn will flow down to us, as always).

(tanner) · (tanner) **Join Date: Oct 2005** 05-13-2008, 4:05 PM

Yeah this new little suprise GM started doing w/ the ECM's caught a few of us offguard. Of course... I left my warranty behind a long time ago somewhere around 430hp when I decided to redo the tranny. Some 200+ hp later with a custom twin set and I don't remember what a warranty does anymore .

(gwnkids) · (gwnkids) **Join Date: Nov 2003** 05-13-2008, 9:23 PM

Look up the PPE filter mod on dieselplace it modify s the factory box and uses the factory blue filter.

The PPE hot + 2 is the tune to get and the turbo back does help alot RBP or MBRP

Check with Chad at Alligator performance for the best price. Easy install and good sound from a 4" system.