hey I have a 08 LMM and I'm looking to do some mods, I was wondering what everyone thought about everything, from intake, exhaust, downpieps, chips, exhaust brakes, leveling kit, everything. Whats the best out there, banks, edge, bully dog? I'm going to be towing a 40ft toy hauler and i want more power.

MBRP is one of the Best for Exhaust, EFI Live is the best for Prog's but PPE, Edge, and Quad are good to. Downpipe, not really needed, just block the EGR. Intake all u need to do is the PPE mod... May want to do a Transgo Jr....

Welcome to the forums.

Stock intake is good for 500HP easily. If wanted to do a different one then look at S&B intake. One thing to stay away from is oiled charge air filters. if other oiled they will mess up the MAF sensor and can kill it to over time. Plus those filters thin out over time if you keep cleaning them. They screw up the readings the MAF sensor will see over time because more turbulent air enters. So best is a dry 7 layer filter.

Leveling kit be better than screwing the Tbars up.

Exhaust depends. You have DPF back, Cat back and Turbo Back to choose from.
Best deep sound will be Turbo Back exahust but i want you to be aware of once you delete the DPF and reprogram the ECM to remove it from the ECM tune you will most likely voided your warranty. The ECM records the last 10 different changes. So if you take your truck in for a engine or transmission problem and have return the truck back to stock done to the tune. They will know once they start looking at the last ECM tunes and notice a non GM calibration code in there.

If you do DPF delete the Edge Evo Race, PPE Hot Race, Quad are the basic standard tuners that can eliminate the codes that will pop up after removing the DPF. The next best is EFILive but this is a full package tuner software. You do not get any tunes with EFILive. You make your own or buy tunes from others. Get EFILive from the vendors that sell it and they provide a tune or two free with purchase through them.

Banks has turbo back exhaust system with thier module system but Banks system does not do DPF delete. Edge attitude is another module system. One benefit with the module system is that it does not alter ECM tuning. So it can be easily removed.

Banks makes a module system with their intake, exhaust , and exhaust brake system.

Only thing running high HP tunes with a DPF on the exhaust is it will plug up quicker and regen more often. Also as mention do a trans-go jr shift kit to help the Allison last longer but it is no replacement for a built transmission. So this should give lots of search terms to use in the search tool to learn what you may wish or not do.

Brian

Do you drive the truck everyday, and are you against removing your DPF?

Tuning- Edge Evo Race, PPE Hot. Efi Live if you want custom tuning
Exhaust- MBRP
Intake-S&B
Down-pipe-Diamond Eye
Inline module-Banks
Leveling kit-Cognito

Tyler
MPF

Take a look at my signature below, mods listed are the best IMO :D

if you decide you want to do something that requires you take most of the front end off of your truck i would definatley install a fluidampner put one in my truck and love it.
also installed an airdog system easy to install and the engine runs smoother and because of the fluidampner it took out the very little engine vibration that it had... smoothest running engine i have ever seen. and i much agree with the guy that said to stay away from the oiled filters not olny what he said they will clog very fast and restrict your airflow. i have a bully dog on mine and like it but i didnt really do much research into it. also have a bullydog power pup programmer for it. love it... neighbor has an 08 cummins with a banks and its ok but i would still prefer to have a BD. and exaust is a must... not shure what would be best for you but i have a 5in on mine

I do drive the truck almost everyday, the dpf i am on the edge if i want to rempve it or to keep it.

The DPF on My Truck Fell off(Wink Wink) and i put the MBRP on there instead... havent had a problem at all with the dealer... My service guy knows its there and that i remove the prog before taking it in... as long as thay cant trace a problem to my mods, they dont care...

I have the 08 and barly get 12 mpg. I just order a dpf delete pipe tha just bolts into the same spot. It even has the bungs for the lines to be put back on..I have a Quad,level kit and going to get a valve cover bypass kit..

Yep have seen some like your suck on mileage. No idea why. It can depend the attitude your in, the way you drive it, the type of terrain you drive like hills or mountains. But hopefully the setup get 3 more mpg.

What is a valve cover bypass kit?

Brian

You take the valve cover breather lines and re route them down under the truck. You then plug the 1 inch hole in the intake. There was alot of oily slim in the intake tube of the turbo. I also took off the 6.6 logo black box on top of the engine and put a 2 inch plug on that.

Ok the PVC re-route option. I figured that was what you meant but wanted to make sure. When you mean 2" plug you mean one that fits inside. If so make sure you a second nut or locking nut on there. I have seen a post where someone has had theirs unscrew and the turbo ate the parts. Needless to say the turbo was shot. I recommend a fern-co cap. Can't fall in that way.

Thanks

Brian

well im still very new to the diesel world and all, what are some of the main advantages to getting rid of the dpf?

You will see your mileage increase 3-4 mpg, and it will let the engine breath. It opens up a few hp just by loosing the exhaust also.

Not to scare you but these are the things if you do a DPF and run into issues. If you run high HP tune and smoke the transmission then you are into a $4000 rebuild with Suncoast III by one of the many builders out there. GM charges way more and your still have stock weak transmission. If injector goes then your around $300 an injector plus labor outside of GM. GM cost for a full 8 injectors is around $6,000 from a post seen lately. Cheaper to go over 60 over injectors and then add a turbo, tune, and dyno for that amount. Now not all have had injector issues. But the percentage is hard to say on LMM anyways. LB7 were the worst. As to save transmission cheap help is a trans-go jr. Nothing like a built one but will help. Also if running HP tune then no wide open throttle in the upper gears 4th on up. Same for up and down shift in those gears. Once you slip it, it will just slip easier and easier over time till time to rebuild. Only slipped mine one but burned the C3 clutch pack when it was torned down. I feel converter was screwed up too.

Brian