2013 Silverado 5.3L Upgrade Path?

Metability · January 11, 2019

Hi all, new to the forum here

My truck recently came out of warranty, and I am ready to do some upgrades. The truck is pretty much stock with the exception of some minor stereo stuff and some 20" wheels and tries from a 2016 GMC Sierra High Terrain. Installing a Top Gun Customz 1.5" leveling kit this weekend.

I do a fair amount of towing. I want to give the truck some more power for those times that it is needed. I tried searching, but I can't find out what most people are doing to these trucks to squeeze some more power from these trucks. What would you suggest? Drivetrain is totally stock. It has 3.42 gears if anyone is interested.

Pic attached of the truck as of yesterday, and a bonus one with the boat behind it.

Thanks for any and all advice!

Lucas

sefiroxx · January 11, 2019

Exhaust will get a bit,

But ultimately, you'll end up going down the path towards turbocharging. Posted heads, cams, upgraded postings and rods, new lower end casting etc. Look at the following on an attempt to blow one up and see the dyno results:

http://www.trucktrend.com/how-to/engine/1213tr-vortec-5-3l-big-bang/

greatmizzou · January 11, 2019

There isn’t much you can do to turn up low end torque with engine mods. You can certainly ramp up high rpm torque tho but it will cost you at towing under 3,000rpm. I’m sure there is something but I haven’t seen it.

All the research I’ve done suggests re-gearing and using the right tire size is the only logical way to add Noticeable towing power.

Where exactly does your truck turn up short while towing...or has it ever completely flat out failed to tow something?

Metability · January 11, 2019

I'm just looking for some additional power over what the motor currently has, preferably on the low-end. The tires are pretty close to the stock size. The boat is pretty easy to tow, comparatively speaking, to say a travel trailer, but it is simply just heavy. I'm sitting around 7k lbs on the trailer and my truck doesn't have as much power as I would like when going up large inclines.

swathdiver · January 11, 2019

1 hour ago, Metability said:

I'm just looking for some additional power over what the motor currently has, preferably on the low-end. The tires are pretty close to the stock size. The boat is pretty easy to tow, comparatively speaking, to say a travel trailer, but it is simply just heavy. I'm sitting around 7k lbs on the trailer and my truck doesn't have as much power as I would like when going up large inclines.

The first thing you should do is get it tuned by BlackBear. The results will be like driving a new truck, especially with the improvements to the transmission.

There are camshafts from Crane and Cam Motion that increase low end torque and do not move the powerband higher which is counter-productive for a truck. You could also consider a change to 3.73 gears. Many will consider these mods too tame but such has always been my way. If you do not want or need to go into the motor, a supercharger will be the best bang for the buck. It will add about 100-120 horsepower and give you all the power necessary to pull that trailer anywhere. These mods will take you from about 315 horsepower to over 450 horsepower.

RMR · January 11, 2019

A custom tune with HP tuners. Your in Vegas so I imagine a dyno tune shop exists. It will free up torque being held back in stock tune. And remapping the AF mixture. Likely not to lose any mpg with this route. I would guess a $600 endeavor. One option.

Metability · January 12, 2019

I am interested in getting the truck tuned. Is BlackBear going to be the most reputable shop for something like this? Does anyone have any experience on tuning these trucks and keeping them able to pass emissions testing? I wouldn't be opposed to purchasing a second ECM to be able to pass emissions still. On some of my older cars, there was a possibility of switching the tune on a basic switch setup. Is that possible?

I was thinking of sticking to quicker upgrades on the motor for now, but I would not be opposed to running a blower on it. I've heard that the 5.3L can hold a supercharger with a decent amount of boost. How well will my 6 speed transmission hold this power?

I am thinking of doing exhaust and a tune for now, followed maybe by gearing. Any other suggestions?

Thank you!

swathdiver · January 12, 2019

1 hour ago, Metability said:

I am interested in getting the truck tuned. Is BlackBear going to be the most reputable shop for something like this? Does anyone have any experience on tuning these trucks and keeping them able to pass emissions testing? I wouldn't be opposed to purchasing a second ECM to be able to pass emissions still. On some of my older cars, there was a possibility of switching the tune on a basic switch setup. Is that possible?

I was thinking of sticking to quicker upgrades on the motor for now, but I would not be opposed to running a blower on it. I've heard that the 5.3L can hold a supercharger with a decent amount of boost. How well will my 6 speed transmission hold this power?

I am thinking of doing exhaust and a tune for now, followed maybe by gearing. Any other suggestions?

Thank you!

It's even easier than that! With the AutoCal device, you can simply flash your stock tune back onto the ECM and go pass emissions and flash it back in the parking lot before heading home! BlackBear can do remote tunes or in-person. I got lucky and was able to meet up with Justin, he lives out your way and am sure he frequents Vegas for tuning sessions. HP Tuners allows you to tune your truck, it will eventually be the path I take but for now wanted to take advantage of someone else's knowledge and expertise. And as Scott mentioned, there might be a great tuner in your area that could tune your truck on a local dyno. Lots of ways to skin the cat and I showed you mine!

The transmission will handle it but be at or slightly over the rated limits, as if it was a 6.2! if your right foot has too much fun you'll have to overhaul it sooner rather than later. Then of course, you can make it near bullet proof.

I have read that our stock exhaust is plenty and an aftermarket one will not offer any performance advantages. Then I read about this one or that adding horsepower or increased mpgs. Still researching that subject. We always upgraded the exhaust on our old muscle cars.

RMR · January 12, 2019

Agree with swathdiver. Exhaust (catback at least) wont gain much, but will get you the sound you may want. I ran 10lbs boost with a Edelbrock SC on a 2012 Tahoe 5.3. Now, I'm at 7000ft, so was still missing some of the dyno corrected 429rwhp and 469rwtq. Dad has had it at 3000ft for a year and still no issues. I did add chrome moly push rods and ARP head bolts - but that LS is tough. As for the transmission, with some torque management mods to limit first and second gear a little and stiffer shifting - zero issues 20K miles later. Just my experience.

Edited January 12, 2019 by RMR
grammer

Metability · January 15, 2019

I think I will reach out to the guys over at Black Bear and see what I can get worked out for a tune. That sounds like a nice option as long as it is switchable. I had a previous go at tuning one of my old cars (1992 ECM) and it went alright, but at this point I would rather have someone who knows the vehicles best to get the job done.

It does scare me a bit about the transmission. I don't really feel like replacing parts that break. Does anyone know what kind of power the stock tranny will hold? Please keep in mind that I will be towing with it a fair amount. Up to about 7-8k lb boats. @RMR did you have to drop the transmission for those mods?

I think that an exhaust will help me out. I don't really care for the loud droning noise that it will cause, so that will likely take some reasearch. Is anyone running headers on these trucks for more power? How do they sound under tow?

What about installing electric fans? I have heard that this can free up some lost power.

Thanks!

LSA

RMR · January 15, 2019

Metability, no Sir. That was accomplished within the HP tuner capabilities. I considered a true shift kit, but with the right nerd behind the laptop - never an issue. The speed shop owner said his 2010 Tahoe with the same trans held up until he got to about 600rwtrq. Then he broke a gear in the differential. Replaced it and pressed on. Even when he swapped out to a 408 stroker twin turbo pushing just over 900rwhp- he just modified the torque management again and has been good to go. I think he does all of his heavy throttle at speed and roll racing sports car. Not a lot of digs and burnouts. Purpose tuning was key.