New GM HD pickups - Air intake design

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GM is teasing us with details of the new HD pickups that are going to debut as 2017 models with a redesigned, uprated Duramax. They haven't given power and torque numbers yet, but here is some information about the new truck's air intake system:

Quote:
New for 2017, Chevrolet Silverado HD trucks feature a patented air intake system that drives cool, dry air into the engine for sustained performance and cooler engine temperatures during difficult driving conditions. The intake system underwent extensive testing based on the most challenging real-world driving conditions to ensure capable performance no matter the weather.

Marked by a dramatic hood scoop, the all-new air intake system provides 60 percent of the air to the Duramax diesel engine from an inlet at the front of the hood. The air provided to the engine is very close to the outside ambient temperature and much cooler than the air under the hood.

Cooler air helps the engine run better under load, especially in conditions where engine and transmission temperatures can rise quickly. Running cooler allows the Duramax diesel to maintain full power and vehicle speed for capable trailering in even the toughest conditions.

There’s also a ram-air effect from the incoming air at highway speed that helps pack more air into the engine. The air filter housing also draws 40 percent additional air from a dry location in one of the front fenders. It blends with the cooler air from the hood inlet before funneling into the Duramax’s combustion chambers. This assures the engine can breathe even if the hood is completely blocked.

“The 2017 Silverado HD was engineered to provide maximum utility for our customers in even the most extreme situations,” said Eric Stanczak, chief engineer, Silverado HD. “While developing this all-new induction system, we considered our customers towing a maximum-weight trailer through the Eisenhower Tunnel on a hot, rainy summer day.”

At more than 11,000 feet above sea level, the Eisenhower Tunnel, is the highest vehicle tunnel in the world and one of the highest elevations for any roadway in North America.

Maximized engine performance requires more than cool air; the air must also be clean and dry. Accordingly, the functional hood scoop includes a unique air/water separator to ensure only combustion-enhancing dry air is drawn into the engine. The air charge enters an expansion chamber containing a sharp, 180-degree turn on its way to the air filter housing. That creates a velocity change that causes humidity or mist to form larger, heavier droplets that are flung centrifugally against the outside wall of the housing. The collected water drains through a valve, while the air charge continues on to the filter housing and into the engine.

Testing the effectiveness of the system was rooted in real-world driving conditions of every degree — from misty rains to monsoon-level downpours; from powdery snow to wind-driven ice pellets; from desert dust to arctic cold.

Surprisingly, torrential downpours do not necessarily pose the biggest challenge, according to Kevin Dunn, global vehicle performance for splash engineering: “Big, heavy raindrops from a thunderstorm are relatively easy to eliminate from air. The more challenging issue comes from the mist-like spray generated by semitrucks on wet highways. Those very fine water droplets prove more challenging to separate from the air. The air intake is an elegant solution that works well with water droplets of all sizes. For customers, the results delivers maximum engine performance and even greater towing confidence.”
 
Quote:
Marked by a dramatic hood scoop, the all-new air intake system provides 60 percent of the air to the Duramax diesel engine from an inlet at the front of the hood. The air provided to the engine is very close to the outside ambient temperature and much cooler than the air under the hood.


GM must have been watching the Weather Channel showing those idiots driving through flooded roadways.

Where do they get the other 40% of air? Gonna put a scoop on top of the cab?
smile.gif
 
Although functional, I really get the feeling this hood scoop is less about tech and performance, and more about style.

I don't think any manufacturer who has done a factory ram air hood has ever gotten results as dramatic as what they're making it out to be.
 
Originally Posted By: MolaKule
Quote:
Marked by a dramatic hood scoop, the all-new air intake system provides 60 percent of the air to the Duramax diesel engine from an inlet at the front of the hood. The air provided to the engine is very close to the outside ambient temperature and much cooler than the air under the hood.


GM must have been watching the Weather Channel showing those idiots driving through flooded roadways.

Where do they get the other 40% of air? Gonna put a scoop on top of the cab?
smile.gif




There’s also a ram-air effect from the incoming air at highway speed that helps pack more air into the engine. The air filter housing also draws 40 percent additional air from a dry location in one of the front fenders. It blends with the cooler air from the hood inlet before funneling into the Duramax’s combustion chambers. This assures the engine can breathe even if the hood is completely blocked.
 
Originally Posted By: MolaKule


GM must have been watching the Weather Channel showing those idiots driving through flooded roadways.

Where do they get the other 40% of air? Gonna put a scoop on top of the cab?
smile.gif



That's the odd thing. They get it from the fender, yet imply there is some source of heat there that makes the air hotter than a chamber in the hood getting baked by engine heat?
confused2.gif


I've done testing with cars that have open cone filters mounted directly in the engine bay. By 25mph, IAT's were within 7 degrees of ambient, so I'm failing to see the major highway speed benefit over taking the air from anywhere else.
 
Maybe the giant emblems on the grill will be turned into a cooler for the air intake.

I saw a Dodge this morning with the giant RAM letters on the front end. I could see them from 3 miles away. I almost wanted to ask him what kind of truck it was because I couldn't tell.
grin.gif
 
http://www.autoblog.com/2016/06/03/2017-silverado-hd-duramax-ram-air-news/

It looks like the Family Truckster 2.0 from the front. That scoop was first and foremost designed for looks! Many manufacturers put the air intake on top of the radiator support so air gets rammed in from the bumper cover/radiator inlet. Hyundai/Kia does this on all their cars. There's no need to have a ram air hood for a cold air/ram air effect. It's for looks.
 
Originally Posted By: Drew99GT
http://www.autoblog.com/2016/06/03/2017-silverado-hd-duramax-ram-air-news/

It looks like the Family Truckster 2.0 from the front. That scoop was first and foremost designed for looks! Many manufacturers put the air intake on top of the radiator support so air gets rammed in from the bumper cover/radiator inlet. Hyundai/Kia does this on all their cars. There's no need to have a ram air hood for a cold air/ram air effect. It's for looks.


I was thinking something from Transformers.
 
Originally Posted By: DoubleWasp

I don't think any manufacturer who has done a factory ram air hood has ever gotten results as dramatic as what they're making it out to be.


Well, that certainly used to be true. Some factory scoops were notorious for sitting in a LOW pressure area at highway speeds and actually trying to suck air out of the engine! The early Mustang Mach 1 was an example that was often cited where the engine would have gotten higher pressure air without the scoop than with it. Of the scoops from "back in the old days," I only know for sure that two were found to be truly effective when tested: the Chevy "cowl induction" hood that had a reverse-scoop drawing air from the high pressure zone at the base of the windshield, and the Dodge Super Bee / Plymouth Roadrunner 6-pack scoop (on the lift-off fiberglass hood) that was ginormous and stuck way up out of the hood boundary layer. Even the Plymouth "air grabber" (early version) didn't do a lot. The later one that pneumatically opened was better.

But its different today- all the cars and trucks sold are very heavily modeled and tested aerodynamically. Cosmetic scoops like the ones on the hood of a base or SRT Challenger don't do much (and aren't connected to the intake tract anyway). But things that connect to the actual intake plumbing, like the Duramax scoop and the Hellcat inner-headlamp intake are tested and do work. Or at least do no harm like the old Mustang scoop did...
 
I'm skeptical for a few reasons:

1. No performance data......at all.

2. How do you give "Ram Air" to a turbocharged engine? Isn't the high-speed turbine doing enough of the air-ramming all of its own?

3. What is allegedly going on in that truck's fender that the air coming in from there is heated, unlike the hood scoop air?

4. How does ram air work, when you have a 180 degree turn to create an intentional air-stall?

5. How does ram air work when you having a gaping opening in the fender, ready to bypass any excess air forced into the airbox?

6. How exactly is there so large a difference between ambient air temperature and this superheated air from the fender that the engine is supposed to run cooler? WHat happened to the radiator and transmission cooler? We don't design those to regulate engine and transmission temps anymore?

Last but not least:

This is a turbocharged engine. The air coming into the filter box is going to be compressed and superheated by the turbocharger. Intercooler design is going to play the largest factor in ultimate IAT's.


I'm throwing up the Bravo-Sierra Flag on this one. Obviously a case where they called in the engineers to help make tangible function of something they so clearly added for purely styling purposes.
 
I expect the Delta block Dmax and 5.3L Ecotec3 in the HD models.
Gone the 4.8 in the vans and 6.0 in both van & truck. Old tech.
Chrome is 1958, as engine badging is 1969.
Suspension and trim package decals and glue-on's are unnecessary.

For example; Denali, Duramax, Allison, 4x4, ZL-1, etc. get hosed off,
along with the place of purchase, at the coin operated car wash asap.
If I want that garbage, I'll stick it on myself.
Hood scoop? A step in the right direction from the glue-on plastic make believe ones.
 
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Amazing how GM can find ways to make the front end larger and larger, which is a detriment to those of us that actually have to use these pickups in tight places, work sites, farm stuff, etc. I have a 2015 2500 and curse it now and then for having the front end it does. Now they want to elevate the hood even more with a scoop. Glad I will not be looking at another pickup for quite some time. I haven't cared for the bloated front ends of these newer pickups. Wish I could have the same front end on mine as my '98 2500 did. This stuff seems more catering to the "hey, I have a diesel" crowd looking for bragging rights.
 
Exactly TT; Is that a truck, bus or locomotive?
I know where this topic came from, dummied down GM Authority.
Oh!! We are losing the torque and horsepower race to Ford and Ram.
Horsepower race in the full size pick up market?
The guys lifting their trucks also delete the DPF and chip the Diesels for what ever horsepower is required to snap the driveshaft and drop the transfer case.
The "off road" suspension package can be ordered with 275/45/22s on the 1500s.
Yeah, I'm going off road with 22s. And how can I service the steering after going off road? Can't, there is only one grease nipple on each side.
Ya gotta love those off-road trucks when they have a load in the box with the headlights pointing at the tree tops.
 
Originally Posted By: DoubleWasp
I'm skeptical for a few reasons:

1. No performance data......at all.

2. How do you give "Ram Air" to a turbocharged engine? Isn't the high-speed turbine doing enough of the air-ramming all of its own?

3. What is allegedly going on in that truck's fender that the air coming in from there is heated, unlike the hood scoop air?

4. How does ram air work, when you have a 180 degree turn to create an intentional air-stall?

5. How does ram air work when you having a gaping opening in the fender, ready to bypass any excess air forced into the airbox?

6. How exactly is there so large a difference between ambient air temperature and this superheated air from the fender that the engine is supposed to run cooler? WHat happened to the radiator and transmission cooler? We don't design those to regulate engine and transmission temps anymore?

Last but not least:

This is a turbocharged engine. The air coming into the filter box is going to be compressed and superheated by the turbocharger. Intercooler design is going to play the largest factor in ultimate IAT's.


I'm throwing up the Bravo-Sierra Flag on this one. Obviously a case where they called in the engineers to help make tangible function of something they so clearly added for purely styling purposes.



My two thoughts: they seem to be very interested in dry air also. I'm not sure why. But if they could remove moisture from moist air then they could have the same kind of air going into the engine under all conditions (humid or dry), leading to more consistent engine performance. Alternatively, seems to me that in order to heat up moisture you "steal" from the combustion heat.

Also, wasn't there an issue for Ford Ecoboost owners with condensation buildup in their intercoolers? I think I heard about VW TDi's having it also. Hydrolock is a very bad thing.

Finally, while the intercooler is meant to drop intake temps, it seems like there is only so much it can do. Under the most demanding conditions perhaps they couldn't size the IC large enough. Thus, if they could eek out a few more degrees of drop in the hood, perhaps that helps.

Dunno. The ram air effect on the engine does sound like marketing. I know under load the engine is moving some air, but the turbo is supposed to be doing all that work (and for free).
 
Originally Posted By: Merkava_4
It's still gonna be a smelly suffocating fume belching diesel truck no matter what they try to do.


?

They're pretty clean today, at least until the owners rip off the stuff.

My TDi was right before SCR/etc hit the market; but it still had a catalyst. At first I thought the loss of that sweet diesel exhaust smell and the gain of the different catalyst-ed exhaust smell was "wrong": but after a bit of time I came to prefer it. Very unobtrusive.

Today I cringe whenever a cold-started gasser drives by me--it smells as if it's dumping gas out the exhaust (it is--the cat hasn't gotten fully warm enough). YMMV.
 
Hey, look!

The GM 'marketing team' has put to paper what the engineers (some of whom are really clued-in) have already known for quite some time.

9720Under20bumper20air20intakes.jpg


mscott683.jpg
 
The messed up thing about that arrangement was that GM engineers discovered that those long tubes had such high internal restriction, that it caused a loss in horsepower compared to hood induction.

Has nothing to do with any "ram" effect from the hood. The hood was just a lower path of resistance.
 
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