2014+ Intakes (CAI) & Air Filters

[Jay Fisher]

Installed a S&B on my 2018 GMC Sierra Denali, and I love the sound and the  throttle response.

[16LT4]

I've never bought into "CAI's", especially considering stock intake does induct cold air.  However, looking at the intake's baffles and the air box restriction, I ordered the Airaid MIT and completed the "airbox mod" the other day.  Now that we've replaced my wife's 135k mile Jetta with a new, 12 mile Pacifica, I don't feel bad about doing some subtle mods to the truck; 1.5" level and some exhaust work will follow.

 

Anecdotal observations after the intake work:

 

1) the truck seems to have a little more throttle response, though is likely to not be visible on a dyno.  It feels like the engine responds quicker to throttle input with less hesitation, which is expected with less intake restriction.  My seat dyno is not calibrated, and it could be aural because

 

2)  beyond 1/4 throttle (via pedal motion) there is some definite intake roar.  Nothing annoying or droaning, but certainly audible; this should make sense, as I've removed the factory intake baffles that exist to quiet intake sound.

 

3) while my seat dyno isn't well calibrated for quantitative power data, it is pretty well calibrated for qualitative vibration data.  My '16 CCSB never had what has been characterized as the "chevy chuggle", speed vibrations, or shifting issues (I am a bit familiar with those, having had a new '17 DCSB Z71 that had all 3 and left my ownership by 12k odometer miles), but did shift and drive about as smooth as a K2 with a 6 speed possibly can.  My biggest surprise is with how much smoother both power deliver and shifts are now by comparison.  Shifts are quicker and firmer, and so far is more difficult to "confuse" the transmission's shift logic.  Say what you will about Dodge, but their ZF 8 speed is perhaps the best transmission out there right now; my 6 speed feels more like driving a ZF in my '14 Laramie than a GM trans (minus the 2 gears).  My hypothesis is that smoother airflow is more consistent airflow, which leads to a smoother CKP signal to the TCM, resulting in smoother transmission operation.  Regardless of power gains, the better shifting alone was worth the mod.  How much is due to the airbox mod vs. the MIT?  No idea, I didn't to them separately.  

 

And, if nothing else, I can visibly see the front of the engine and its drivebelt now during oil change inspections; I had my oil pressure sensor replaced in July under warranty, but have no idea how long it was leaking due to difficulty in seeing the area beneath/behind the factory box.

 

[HoosierZ]

I also did the Airaid tube with their dry filter and opened up the inlet of the stock air box. It definitely made the throttle more responsive and it has a nice growl around 2k rpm under certain loads and throttle position. 
 

Found a pic of the air box mod. I popped off the seal between the air box and fender, cut out the side of the box and re-attached the seal with caulk. 

Edited November 14, 2021 by HoosierZ

[M1ck3y]

Does anyone here have a afe momentum gt or magnumforce air intake?

 

I'm trying to find out the size of the exit closest to the throttle body. And if it necks down smaller then the pipe upstream.

[SeekAndDestroy]

On 12/20/2021 at 3:02 PM, M1ck3y said:

Does anyone here have a afe momentum gt

I had the momentum GT. Sold it. Here is a pic. It’s the same size as the 6.2 throttle body bore

[M1ck3y]

13 minutes ago, SeekAndDestroy said:

I had the momentum GT. Sold it. Here is a pic. It’s the same size as the 6.2 throttle body bore

 

Thanks! I wanted to make sure it wasn't a smaller opening for the 5.3.

 

I take it you weren't happy with It?

[SeekAndDestroy]

On 12/21/2021 at 6:48 PM, M1ck3y said:

I take it you weren't happy with It?

It made cool noises when you punched the gas, I don’t think it added power. When the temp dropped below 0 the fuel economy took a dump. My wideband plus HP tuners was the same price, and totally worth it. Intake was way overpriced for what it does

[M1ck3y]

15 hours ago, SeekAndDestroy said:

It made cool noises when you punched the gas, I don’t think it added power. When the temp dropped below 0 the fuel economy took a dump. My wideband plus HP tuners was the same price, and totally worth it. Intake was way overpriced for what it does

 

I went back to the stock intake a while ago and said I would never buy aftermarket again.

And here I am buying one 

 

I'm also working on porting a intake manifold for a 95mm and need an intake that will fit. Hoping I can open up the afe intake little bit too.

 

4 month nationwide backorder for this intake  

 

 

Edited December 23, 2021 by M1ck3y

[BigAL-evation1500]

On 12/20/2021 at 2:02 PM, M1ck3y said:

Does anyone here have a afe momentum gt

I recently installed the Momentum GT oiled on my 2018 5.3. I like how it comes with couplers for the both the 5.3 and 6.2 throttle bodies. I noticed a difference, and I was coming from the Airaid tube and their dry filter in stock box. I also have the diablo tuner on the 91 octane tune. I'm happy with it so far. I'll upgrade to the L86 intake manifold and throttle body soon so I'll just need to swap out the couple for that. 

[pokismoki]

the stock CAI is awsome when you pull the baffle out..  only other mods for a CAI is to remove the valvecover hoses , replace them with UNI valve cover filters, this keeps out any oil from getting into the intake , and stops any unmetered air getting past the MAF

[16LT4]

On 11/14/2021 at 12:42 PM, 16LT4 said:

I've never bought into "CAI's", especially considering stock intake does induct cold air.  However, looking at the intake's baffles and the air box restriction, I ordered the Airaid MIT and completed the "airbox mod" the other day.  Now that we've replaced my wife's 135k mile Jetta with a new, 12 mile Pacifica, I don't feel bad about doing some subtle mods to the truck; 1.5" level and some exhaust work will follow.

 

Anecdotal observations after the intake work:

 

1) the truck seems to have a little more throttle response, though is likely to not be visible on a dyno.  It feels like the engine responds quicker to throttle input with less hesitation, which is expected with less intake restriction.  My seat dyno is not calibrated, and it could be aural because

 

2)  beyond 1/4 throttle (via pedal motion) there is some definite intake roar.  Nothing annoying or droaning, but certainly audible; this should make sense, as I've removed the factory intake baffles that exist to quiet intake sound.

 

3) while my seat dyno isn't well calibrated for quantitative power data, it is pretty well calibrated for qualitative vibration data.  My '16 CCSB never had what has been characterized as the "chevy chuggle", speed vibrations, or shifting issues (I am a bit familiar with those, having had a new '17 DCSB Z71 that had all 3 and left my ownership by 12k odometer miles), but did shift and drive about as smooth as a K2 with a 6 speed possibly can.  My biggest surprise is with how much smoother both power deliver and shifts are now by comparison.  Shifts are quicker and firmer, and so far is more difficult to "confuse" the transmission's shift logic.  Say what you will about Dodge, but their ZF 8 speed is perhaps the best transmission out there right now; my 6 speed feels more like driving a ZF in my '14 Laramie than a GM trans (minus the 2 gears).  My hypothesis is that smoother airflow is more consistent airflow, which leads to a smoother CKP signal to the TCM, resulting in smoother transmission operation.  Regardless of power gains, the better shifting alone was worth the mod.  How much is due to the airbox mod vs. the MIT?  No idea, I didn't to them separately.  

 

And, if nothing else, I can visibly see the front of the engine and its drivebelt now during oil change inspections; I had my oil pressure sensor replaced in July under warranty, but have no idea how long it was leaking due to difficulty in seeing the area beneath/behind the factory box.

 

 

 

Whelp, that was a brief experiment in failure.  Between 1-2k RPM under medium load, the truck elicited a groan; not a drone or intake sound, but a vibrating groan of disappointment and loathing.  I never checked the fuel trims out of laziness, but my idle dropped and the truck had a low-idle-RPM miss; nothing major, but just enough to hear on the exhaust note.  Across the cold heart of winter, my fuel economy also took a major dump, so as a follow-up to the air-box-mod experiment, I reversed it.  I found the old intake flange and welded it back to the removal box-plate, and reattached.  The groan went away, as did a little bit of exhaust sound (both wins), but an apparent loss of throttle response too.

 

On the way to work yesterday, my fuel economy rose by 1 full mpg on the 50-mile-average DIC display in only the first 4 miles, on a sub-freezing cold start and open-loop warm-up.  By the end of the day and 30 out of those 50 miles, fuel economy went from 11.7-15.0 mpg.  After another 15 miles this morning, the 50 mile average is up to 15.7 mpg, and still climbing.  The ride home today will be enough to erase the airbox-mod miles from the calculation; I bet I see over 16 by the end of the day.  Returning the airbox to its factory state also raised my idle by ~100rpm, which smoothed out the idle considerably.  The exhaust note is nicer when cruising.

 

Lesson learned on this one.

 

[14burrito]

49 minutes ago, 16LT4 said:

 

Whelp, that was a brief experiment in failure.  Between 1-2k RPM under medium load, the truck elicited a groan; not a drone or intake sound, but a vibrating groan of disappointment and loathing.  I never checked the fuel trims out of laziness, but my idle dropped and the truck had a low-idle-RPM miss; nothing major, but just enough to hear on the exhaust note.  Across the cold heart of winter, my fuel economy also took a major dump, so as a follow-up to the air-box-mod experiment, I reversed it.  I found the old intake flange and welded it back to the removal box-plate, and reattached.  The groan went away, as did a little bit of exhaust sound (both wins), but an apparent loss of throttle response too.

 

On the way to work yesterday, my fuel economy rose by 1 full mpg on the 50-mile-average DIC display in only the first 4 miles, on a sub-freezing cold start and open-loop warm-up.  By the end of the day and 30 out of those 50 miles, fuel economy went from 11.7-15.0 mpg.  After another 15 miles this morning, the 50 mile average is up to 15.7 mpg, and still climbing.  The ride home today will be enough to erase the airbox-mod miles from the calculation; I bet I see over 16 by the end of the day.  Returning the airbox to its factory state also raised my idle by ~100rpm, which smoothed out the idle considerably.  The exhaust note is nicer when cruising.

 

Lesson learned on this one.

 

 

So Airaid tube and airbox mod = no dice?

[16LT4]

1 hour ago, 14burrito said:

 

So Airaid tube and airbox mod = no dice?

 

Si.  I kept the Airaid tube (stock box and filter) but ditched the airbox mod.  My fuel costs, so far, have decreased by a third as a result of the un-modification. 

[14burrito]

8 hours ago, 16LT4 said:

 

Si.  I kept the Airaid tube (stock box and filter) but ditched the airbox mod.  My fuel costs, so far, have decreased by a third as a result of the un-modification. 

 

Interesting.

 

All that comes to mind would be velocity vs volume.

[16LT4]

8 hours ago, 14burrito said:

 

Interesting.

 

All that comes to mind would be velocity vs volume.

By this morning, including some several near-full-throttle acceleration events, downshifts, and miles driven, fuel mileage increased 40% post-un-mod, hitting 16.4 mpg from its airbox-modded 11.8 mpg.  The truck stays in V4 longer, even at 30 mph uphill drives in 5-6th gear.  Note, this isn't an improvement over stock, just returning to stock.  I predict, as a result of opening up the exhaust flow by deleting the flapper valve (which was freezing shut and choking the flow), total mileage will increase slightly over what it was before any modifications.  I don't ever remember hitting mid-16s on winter morning commutes in the last 30k miles, and that is with increased wind resistance due to front level kit and bull-bar installation.

 

Stoichiometrically it makes sense, as more air needs more fuel, especially when said air is denser (winter), I was just surprised the difference is so pronounced.  Before the airbox mod, guys said they saw anywhere from minimal drop to actually gaining mileage, because "the engine makes more power and doesn't use as much throttle pedal application to accelerate."  Well, in this little anecdotal data point, that hypothesis is junk science.  I only regret not checking fuel trims before-after to see what's going on on the fuel map, but the fuel savings is telling me all I need to know.  The shape of the in-fender air intake may very will actually improve velocity/flow, acting as venturi; just guessing, but I'd love to see a flow experiment.

 

With fuel prices as they are and the weather starting to warm up during the day, I'm switching back to E85 this afternoon and taking a 400 mile trip to work at back tomorrow and will report back on the effect of that mileage.