Upgrade package - exhaust/suspension/wheels

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Danneman

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I hope I put this in the right category, apologies if I did not.

I'm looking to make a few changes to my 2018 Tahoe LT, but the kind of upgrades I prefer to stick to with for my daily driver are things that the factory could just as easily have made - like selected parts from the next trim level up.

What I'm hoping is that someone could confirm that these changes - together, as a package - will work for my vehicle and should deliver an overall improved driver experience, as in a GenMo engineer would say "yeah, this is fine, you're not doing anything inappropriate for the vehicle, go for it."

  1. "Performance Exhaust" - part #19329322 - this is appears to be the cat-back system that came on the 2018 RST, but for the 5.3L.
  2. Magnetic Ride Control - I've seen a lot on people wanting to revert back to conventional suspension after their MRC needed maintenance due to cost, but I can't find a lot on going TO it. Is this done? Is there a kit?
  3. 20" wheels - I know the speedometer would need to be dealt with, I think I heard I might need to have something in order for a mechanic to adjust it, but that not all Tahoes have it. Is that right? Are there other implications, like shift points? ECU retune?

Thanks for any help. -DW
 

Brian71

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I can only answer the wheel question

In my case my Tahoe came with 22 inch wheels. In the winter I have a separate set of wheels/tires. They’re off my old 06 Tahoe. They’re 17 inch rims. The tire size of the 17 inch wheels vs. The 22 inch wheels are virtually the same. I’ve swapped the 22 inch wheel/tire combo for 17 inch wheel/tire combo for 2 seasons. I’ve had zero issues. No issue with speedometer or shift points.
I’m planning on replacing the 22 inch wheels for 20 inch wheels
 

Doubeleive

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1. Waste of money, muffler shop can build you something cheaper on the spot, but otherwise it should bolt right up
2. no you cannot upgrade to MRC, you maybe could if you had a ton of money and complete wiring harness and programming and lots of free time to experiment
if you are looking to tow and not have sag you could easily add helper bags, otherwise you could change over to bilsteins 4600/5100 or fox adjustables, etc
3. wouldn't worry about the speedo at worst it would be 2-5mph off, it can be corrected with a speedo programmer, nothing else required
 

CMoore711

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@Doubeleive is spot on. Don't waste your money on a cat-back exhaust system.

1. Just purchase a weld-in muffler that you're local exhaust shop can weld in and it'll cost you $200-$300 (max) for the muffler and labor. I would consider removing the exhaust flapper valve located after the muffler and replace with a straight piece of pipe. This exhaust flapper functions for the AFM.

2. Changing to MRC suspension would be a huge undertaking and cost a lot of money; Not so much for the shocks and struts themselves but as mentioned above more so on the electronic side of things. Modifying factory body harnesses and connections to all 4 corners of the vehicle, new/modified BCM (Body Control Module), etc. etc. It'd be more cost affective to trade in your vehicle for a different one with MRC from the factory if you wanted MRC that badly.

3. You don't have to extensively modify the ECM to adjust for different tire sizes. This device here would work well for your application:

In addition to making tire size adjustments to your speedo, it also provides a few other user friendly adjustments that will improve overall driver experience. And with the money you'll save from not buying a complete cat-back exhaust system it should fit into what you're looking to spend.

How many miles are on your '18 Tahoe?
Have you ever replaced any of the suspension components (shocks, struts, control arms, sway bar bushings and links, tie rods) or still on all original parts?
 

15burban

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For the "wheels" going to be a bigger rim won't effect your speedometer as long as the tires on the new rims are the same size. If you go bigger or smaller with the tires then you're speedo will be off.
 
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Danneman

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For the "wheels" going to be a bigger rim won't effect your speedometer as long as the tires on the new rims are the same size. If you go bigger or smaller with the tires then you're speedo will be off.
 
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Danneman

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Thanks everyone for their thoughts. If there is a non-zero chance that my vehicle already has some or all of the MRC wiring, does anyone know how I could confirm? What would I look for, where?
 

tooleyondeck

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Thanks everyone for their thoughts. If there is a non-zero chance that my vehicle already has some or all of the MRC wiring, does anyone know how I could confirm? What would I look for, where?
You could seriously do a complete airbag suspension for less than what it would cost to rip out your entire wiring harness, find out what you do and don't have, hunt down each component from GM (probably have to do that based on a VIN for a vehicle that has MRC), install all the necessary components to support the MRC system, and have your ECU reprogrammed. Just typing all of that was stressful lol
 

Coolman1987us

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This device here would work well for your application:
The mpvi3 from HP tuners is $400. The license for my 08 hoe was $100 (different for each generation). I not only shut off AFM but can modify hundreds of other settings for less than this waste of money.
 

Doubeleive

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You could seriously do a complete airbag suspension for less than what it would cost to rip out your entire wiring harness, find out what you do and don't have, hunt down each component from GM (probably have to do that based on a VIN for a vehicle that has MRC), install all the necessary components to support the MRC system, and have your ECU reprogrammed. Just typing all of that was stressful lol
Um where are these "components" going to plug in?
 

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