INTJ

I would like to see those numbers as well, but I’d bet that even a 30 RWHP increase would only gain about .3 sec in the 1/4 mile. That said, I am more concerned about mid range power increases. That may not have as much of an improvement in 1/4 mile times but will help response and acceleration in and out of traffic at cruising speeds.

To take the least amount of risk we can’t do anything to our trucks. There are some dealerships that are that fussy about any mods. Other dealerships are less fussy. Also, I don’t think we even have to use the dealer for warranty and extended warranty work—just need an approved repair facility, though I would thoroughly research that first. So the question becomes how much risk are we willing to take? The extreme end of the spectrum is putting a BIG HP tune in a Duramax. If we thrash the trans while doing that we aren’t going to get warranty coverage and rightly so. On the other end, putting an intake, cat back, and mild tune in a gas engine is unlikely to make enough extra power to break anything. I am am doing an AFE intake, Borla cat back, and Superchips tune for my year-old 2018 5.3 with 13,000 miles on it. Superchips said that an intake and cat back with their canned performance tune will add about 30 HP. The risk of breaking something with that is very low, and if I do need warranty work I’ll put the stock tune back in and maybe the stock intake. Most dealers I have dealt with say to bring it in stock—I don’t expect any issue with a cat back. With two different tuned Duramaxes all I did was flash back to stock and the dealer covered the repair, but the warranty items were small—a sensor and a TCM. I wasn’t trying to cover a fried transmission. Big tunes in the Duramax without beefing the trans and then trying to get warranty on damaged drivetrain components are a big part of why GM got so fussy about mods and warranty, Magnuson-Moss Act notwithstanding. Also, Superchips offers a two-year powertrain warranty, which eases the risk even more.

While I have no interest in the argument you’re having with Mileguru, I am not sure your comments about intakes and airboxes are universally applicable. For about 15 years I was deeply into Duramaxes and with a turbo diesel and the intakes on the LB7, LMM, and LML, there wasn’t much of an advantage until you exceeded 550 RWHP. And as we all know getting that much HP out of a Duramax is easy so there was a lot of testing done at HP levels over 550 RWHP. I think it’s different with naturally aspirated GM pickups. Blackbear’s posted dyno results confirm what intake manufacturers are showing with their own dyno results. Now I suppose one can argue it’s in Blackbear’s best interest to confirm the dyno results since they sell those products. However, when you look at all these posted dyno results, they do show all the parameters and for the results to be fabricated would mean that all these companies are lying and hoping not to get caught. I think that is less believable than the claims of 10-20 HP increases with an Intake. Another reason I am inclined to believe the intakes help at stock HP levels is because a naturally aspirated engine has to suck in all the air it uses. A turbo (or supercharged) engine forces air in and is much better able to overcome any restrictions in the airbox/intake system. So an improvement in flow that won’t help a turboed engine may very well help a naturally aspirated engine.

I wonder what happened? My 2011 LML was usually within .2.

The DIC on my truck is a minimum 1-1.2 mpg rosey. It is the least accurate one I have found. Are others that far off hand calculation?

After a bunch or research I went with the aFe Magnum Force Stage 2 Pro 5R Air Intake Systems (54-12332). I also got the filter cover and the dry element for those times when I might be out in dusty conditions. Living in Oregon I needed a CARB approved CAI and both AFEs and Blackbear’s dyno results show a real increase in HP. I am hoping for a little better mileage too—we’ll see. I also am adding a Borla touring exhaust to make the CAI work better.

All right you neer-do-well influencers of financial spend................ I am one of those guys who reads a lot and posts very little. And based on that reading on this thread as well as a bunch of phone calls to Borla and AFE, I just ordered this: Borla Touring with dual side exit (140544), aFe Magnum Force Stage 2 Pro 5R Intake (54-12332) plus a cover for the air filter and a dry element as well as the oiled. As a hot rodder from way back I was initially skeptical of the power and mileage gain potential, but it seems those numbers are real. I really don’t care to make my truck noisy (competition shooting and lead trumpet playing satisfy any need I have for sound), I just wanted more exhaust flow so the intake will work better. That said, I do like the sound of the Borla Touring. The Borla rep told me that the Borla Touring was slightly louder than the GMPP Borla, which is different than what I have read here. He also said there wasn’t an issue with AFM noise with their system. He said GM uses the flapper to take out the helicopter noise and Borla just engineered it with the muffler design. That is also different than what I read here. l’ll soon find out if the sound level and pitch is acceptable to these nearly six decade old ears. Anyway, thanks to all of you who have posted your thoughts, ideas, and experiences!!

Issue with Westin Pro Traxx 5” Oval Nerfs I have a new 2018 1500 LT 4x4 Double Cab with Max Tow. I got it last week and I am gong through the normal drill of setting it up, something I have done way too often over the last 40 years. I like polished stainless so I decided to try a set of Westin Pro Traxx 5” Oval Nerf Bars. I don’t know how may sets of nerfs I have installed, but it is usually a straightforward and easy task. The end of all this is the bars are 1/2” lower in the front vs the rear relative to the body line of the truck. They should be completely parallel. There were also significant installation issues. The brackets were supposed to be “B”, “C”, and “D”. I had no markings on the Bs but they were easy enough to figure out. The other two were marked “D” and “p”—yes, a lower case “p”. The Bs fit in their indicated positions without issue. I tried the rear most D and p rear brackets on both sides to see if it I could get the bars level front to rear but it didn’t matter. The p bracket was made so there wasn’t enough space to install the supplied flat washers—I just had to leave that off. Also, there isn’t enough clearance between the bolt head and the side of the bracket to fully tighten the lower mount, so I had to run the bolt differently that what they showed. The also published torque specs that were too high. There are bolt-clips that allow the bracket to be bolted to the sheet metal, and they call for 15 ft lbs. I didn’t like how it felt tightening those bolts so I carefully worked up the the 15 ft lbs. That worked fine until one clip broke well before 15 ft lbs. I was able to work around that by swapping a clip and the using a nut in that bracket, but I didn’t exceed 10 ft lbs on the rest of the brackets. I also had two hex bolts that hold the bars to the brackets wallow out before I got to the specified 30 ft lbs. I am not excited about mounting to the sheet metal. I prefer brackets that bolt to body mounts. When I removed the bracket where the clip broke, I discovered the sheet metal hole had distorted under the torque of fastening. I guess I will call Westin on Monday and see why my bars and sloping down and see if the sent me the wrong rear brackets. The brackets certainly look like what is shown in the instructions.