Cold Air Induction ?

[dustybundustbuster]

I looked at them, but $400 doesn’t make sense to me. I threw a K&N panel filter in the factory box. It changed the sound a bit and isn’t restrictive and that’s all I was interested in.

As mentioned, I believe the factory box draws air from outside the hot engine bay, so it’s already a cold air intake system.

 

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[dustybundustbuster]

In my younger days, I was always looking to change things out like the airbox. All it ever added was more noise. Fast forward to last year and I was watching the Motor Trend show Engine Masters. They tested cold air boxes and found NONE of them increased power. The power increase was eliminating MULTIPLE bends in the system. The results REALLY surprised me. I think the increased noise always makes people feel like they're getting mor HP, but you're really not.

They also tested using various octane fuels. In naturally aspirated engines, the higher octane DID NOT improve HP, but was recommended for turbo and super charged engines for better performance.

As far as the higher octane fuels go, I use them because of the additive packages. I am fortunate that my employer pays for my fuel, so the extra cost isn’t affecting me. I would probably add my own additives if I were using the lower grades of fuel. I don’t want my engine to have any excuses to give me problems because of buildup on the valves or injectors. As it is, I still run added Techron or other additives in the high grade fuels every 3-4 tanks.

For the airboxes, you didn’t mention what vehicle they used for testing. Factory vehicles are carefully engineered to maximize efficiency in all of the systems, and that comes with trade offs. Introducing more intake air can help a bit, because the intake systems are designed to adjust to it. But there are built in ceilings in place, including the amount of fuel and spark that’s available, and then everything downstream from the airbox.

Engines built for high performance have systems that are designed to forgo efficiency and longevity for performance. Factory trucks do not.

Obviously it’s not a 1:1 comparison, but it’s similar to our bodies. We can introduce more fuel, but unless we include more exercise and recovery, they are capped as to the benefits we receive from the food. And, over time, if adjustments aren’t made, we get fat and the other systems for dealing with it break down. Our arteries clog, our joints wear prematurely, our liver, heart, and kidneys suffer, our endocrine systems get overloaded, etc.

You’re not going to destroy your truck with an intake and taco Tuesday isn’t going to destroy your body. You just have to be realistic with your expectations.

Also, it’s totally ok to spend money on a cool looking intake that makes a cool sound, even if you don’t get a ton of hp from it. Life is hard. As long as it isn’t hurting anyone else, enjoy yourself!

 

[CM_Admin]

In my younger days, I was always looking to change things out like the airbox. All it ever added was more noise. Fast forward to last year and I was watching the Motor Trend show Engine Masters. They tested cold air boxes and found NONE of them increased power. The power increase was eliminating MULTIPLE bends in the system. The results REALLY surprised me. I think the increased noise always makes people feel like they're getting mor HP, but you're really not.

They also tested using various octane fuels. In naturally aspirated engines, the higher octane DID NOT improve HP, but was recommended for turbo and super charged engines for better performance.

Respect your opinion, but, disagree.
Here is a communication from Summit Racing to dispute your claims,

For your 2025 Sierra 1500 AT4 with the 6.2L L87, the Roto-Fab CAI is one of the better-known intake upgrades

With NO tune:
+5 to +12 horsepower (peak) small torque bump at higher RPM most noticeable change: throttle response, intake sound (much louder induction noise)
You’ll feel it more than you’ll see it on paper.

With a proper tune: +10 to +20 hp (combined intake + tuning gains) improved mid-range torque better throttle mapping.

For the 6.2L L87, the Roto-Fab CAI is one of the strongest aftermarket intake options. It won’t transform the truck, but it will sharpen throttle response, add induction sound, and give a modest horsepower bump — especially when paired with a tune.

 

[Don S]

The report sounds great, but it's coming from the company that is selling the units. I was able to see with my own eyes the testing that Motor Trend did on TV, showing the results after each engine pull. Unless someone on here installs the unit and does a dyno test both before and after, it's had to believe the results. Why are the results always in a range, like +5 to +12. It should be a specific result on a new truck, like +9.
Lastly, what tune, no one I know is able to tune the GMC as the ECM is locked, unless there is something new out there.

 

[TravisJr]

Lastly, what tune, no one I know is able to tune the GMC as the ECM is locked, unless there is something new out there.

Then you need to meet more people. The L5P is certainly unlockable and tuneable through at least the 2024 model year, and the L87 through at least the 2025 model year.

Although a couple years old, here’s a video with dyno tests of stock, S&B and WC Fab intakes. The Cliff’s Notes are that the aftermarket offerings provide a negligible increase in HP to a stock engine, but start to generate noticeable gains on tuned engines, which further increase with the aggressiveness of the tune.

Your truck, your money, so do whatever you please, but the data is there.

 

[-b-rian]

Why are the results always in a range, like +5 to +12. It should be a specific result on a new truck, like +9.

Numbers vary because of dyno’s, locations, weather, tires, fuel, etc. Mustang dyno, chassis dyno, engine dyno. Is it in-ground or above ground. Are we on the east coast or west coast? How high above sea level? How hot/cold is it outside? How much humidity? What size rim? What size tire? Are the tires aired up? Is there an additive in that tank of diesel?

As for tuning, my 25’ is tunable, both ECM & TCM. I believe they are able to do 26’s as well. Most shops prefer that you’re deleted before tuning, but there’s a few guys out there that are reputable with stock trucks.

 

[Don S]

Then you need to meet more people. The L5P is certainly unlockable and tuneable through at least the 2024 model year, and the L87 through at least the 2025 model year.

Although a couple years old, here’s a video with dyno tests of stock, S&B and WC Fab intakes. The Cliff’s Notes are that the aftermarket offerings provide a negligible increase in HP to a stock engine, but start to generate noticeable gains on tuned engines, which further increase with the aggressiveness of the tune.

Your truck, your money, so do whatever you please, but the data is there.

Thanks for proving my point.......negligible gains.....your own words.

 

[TravisJr]

Yes, those are my words. Partially. You left out the part where I explicitly stated “to a stock engine.” I then further elaborated on the quite appreciable gains that they make in a tuned engine. My full comment was “aftermarket offerings provide a negligible increase in HP to a stock engine, but start to generate noticeable gains on tuned engines, which further increase with the aggressiveness of the tune.” To act as if you can’t parse out the nuance in that statement seems disingenuous, at best.

We are in agreement that there is next to no HP gain from a CAI on a stock engine.

We will remain in disagreement about your insinuation that the GMC cannot be tuned. It may be true that no one YOU know can do it, but that is not reflective of reality.

Have a great day.

 

[RebelDS]

Sounds like the increase in HP is coming from the tuning, not the CAI. For decades that I’ve been around them it’s always been the thing to do to add the “chip” to get the big increase. The CAI has just become the cool thing to do but it mainly just changes the sound. Most who spend all that money and effort are not going to claim it was a wasted effort