EIKON

That’s been a common complaint or observation on the 2020. The brake functions the same as the 17-19. But the transmission functions differently. Also keep in mind the previous years in the L5P would be a lot more noticeable due to the spread in the gear ratios. The 10 speed has to drop several gears in order for it to be as noticeable. I haven’t had any issue with it doing it’s job and I’ve towed loads at max gvwr. It just isn't as pronounced as previous generations. It’s main function is for downhill speed control and it does a very good job of that, for me. YMMV.

I’m on my mobile and can’t see your signature. I’m assuming this is for a 6.6 gas truck. I would do the 3” Also, I would suggest using a muffler that isn’t a chambered design. Magnaflow and MBRP would bee good choices. Chambered mufflers aren’t going to flow as well and often times cause drone on these engines.

Well here’s the thing, GM can tell when an ecm has been swapped. Basically no matter which route you go, if you have a catastrophic failure and GM feels it’s worth spending a few bucks digging, pretty much all power adding devices are subject to being found. While certain devices do not leave a “fingerprint” in the ecm. There are various ways GM can piece together that more torque was produced by the engine than it can produce from the factory. Rumor has it that there is an invisible tuning option. But it’s not public ally available. Those guys are pretty tight lipped.

Your current available option are a few brands of inline tuners (none of which I would offer to my clientele at this time). There are also several companies currently offering direct ecm tuning. I’ll touch on that shortly. Banks Derringer and Edge Pulsar in-line modules that are currently in beta testing. Both are viable options for those not wanting to go to direct ecm tuning. The only direct/complete ecm tuning options commercially available at this time are companies using HPTuners software. In order to proceed this route, the factory ecm must be replaced with an ecm modified by HPTuners to allow software changes. This incurs a significant cost but allows more significant changes than an inline module will allow. Once the factory ecm is replaced, the modified ecm can be “tuned” by whichever tuning company you choose.

The stealth module is a very similar in function to a number of other in line tuners on the market for the L5P duramax engine. After reviewing a number of different modules and an ecm replacement option- I would not recommend the stealth as an option to my clients. That being said, the stealth is a viable performance device. Just not the inline tuning device I would suggest. Which is why I do not install it nor suggest it to my clientele. Do your own research and make your own informed decision. There are two viable inline tuning options on the market at this time(just my professional opinion) and one commercially available ECM tuning option. In the end, if you choose to alter the factory calibration of your L5P, understand that you are potentially accepting any engine, transmission, drivetrain, or powertrain issues as your own. I am well aware of moss magnuson and how it is intended to impact aftermarket equipment. It’s intended purpose is not for devices to increase work load in factory components. Back to stock equipment failures and warranty issues... While many of those issues can and and will be handled under warranty, if GM chooses to dig deep enough, there is a very good likelihood that additional power can be seen. Just because a given device does not leave a “fingerprint” directly in the ecm, does not mean that it cannot be seen in logs or other areas of the current architecture. As I inform all of my clients, if you exceed the factory settings for the vehicle, with the proper tools, additional power/torque may be viewed.

These are 20x9 +12. I had tried to stay with a 20x9 +18. I just had a hard time finding a wheel that fit my tastes. I wasn’t looking for a black or a chrome wheel. So the choices start getting limited.

Thank you. The wheels are some inexpensive wheels from Vision. Vision Turbine

My truck was only 1 and 1/4” higher in the rear than the front, stock. I kept mine pretty simple, I dialed in an inch on the front. That took out most of the rake. But didn’t put it dead level. I like my tread blocks flush with the fender and not sticking beyond. I went with a 20x9 +12 wheel and a 295/65/20 tire. That tire measures 35.3” tall. Which puts it right in between a 35 and 37. Tires labeled 35, typically measure in mid 34” range and tires labeled 37 typically measure in mid 36” range. I have zero rub. Off road at full lock, I would expect some fender liner rub. But have not encountered it yet.

Also check out https://www.peragon.com/ I had their cover on my 2015 RCSB truck and loved it. I’ve since installed the same brand cover on two friends trucks. Sold the truck. Just pulled the the cover off my truck after 3 years of ownership and it still looks great. I’d recommend their product again.

Have someone with a non generic scanner do a computer diagnostic prior to going to the transmission shop. Generic code ode readers won’t poll/read the manufacture specific codes or posssibly the additional modules on the truck. Most code readers only pull the generic obd2 codes.

The dealer is only allowed to put in calibrations gym has approved for your VIN number. If you want to add e-85 ability, you’ll have to do it aftermarket.

Physically that’s about it. But you have to add the ability in the tune.

While I didn’t illustrate it in my previous post, I had meant to point our that if you tune it on e-85 or with an ethanol sensor then you will make even more power. However unless you live in an area that heavily discounts ethanol fuel, it will have a higher cost per mile to run. I prefer to optimize the tuning for whatever fuel I have available. If all all you have is low octane fuel, then so be it. Tune it the best that you can for it. If you have mid grade, then tune for that. If you have premium, even better. For those fortunate enough to have e-85 and are willing to take the hit in the wallet to run it, then tune for that and get even more. Most of of the benefits of a good tune on relatively stock trucks, don’t have to do with peak power numbers. But you can very dramatically impact the feel of the truck, throttle tip in, throttle linear feel, torque application, transmission shift timing/patterns, etc...

Unfortunately not only is e-85 not available everywhere, but it also does not contain the same energy per gallon as regular gasoline. Because e-85 has a higher effective octane rating, the factory can take advantage of a more aggressive timing curve and higher overall timing. But, because of the lowwr overall energy volume per gallon, you must use more e-85 fuel to operate the engine. So e85 is cheaper per gallon however it takes more fuel to operate the engine. I have e-85 available to me. However unless the engine is turbocharged or supercharged where I need the additional octane for tuning purposes, I run my trucks on normal e-10 gasoline. The math for me works out. It’s cheaper to run e-10. When i I tune a truck, I tune it three times essentially. Regular (87 octane), premium (91/93 octane), and e-85. If the the truck doesn’t have an ethanol sensor then I add one. You’d be surprised how often your e85 is actually e60-65.

My 2015 made it 500 hard miles before I put on the kooks longtubes and a full exhaust. Added a clean air separator, modded the air intake, tuned out the AFM, and added an alchohol sensor. Ran it that way until 50k before I did the cam, converter, and swapped out the AFM lifters for LS7 style. The AFM lifters looked better than any set of AFMs that I have pulled out of 10-15k engines that had active AFM. Just turning the system off helps a bunch in my opinion. Some guys will argue otherwise. Ive seen them fail on other trucks even turned off. Not saying otherwise. But I believe turning them off early really helps.