Helmholtz Resonator
Thread Starter
Racer
Joined: Nov 2013
Posts: 369
Likes: 2
Ok so it says nothing about increasing volumetric effieciency, just controlling intake noise which they deem undesirable to passengers in the vehicle.
Probably LS7 passengers want more noise and they feel LS3 passengers want quiet.
I feel a lot better about swapping my LS3 air intake for the LS7 one now.
Probably LS7 passengers want more noise and they feel LS3 passengers want quiet.
I feel a lot better about swapping my LS3 air intake for the LS7 one now.
Melting Slicks
Joined: Jul 2010
Posts: 2,999
Likes: 242
From: Surprise, Az
Pretty interesting, thanks for sharing your research. I would not have thought GM would have gone to that much trouble just for noise reduction. I think most agree the LS-3 intake system is pretty efficient and there is little to gain with aftermarket CAI setups. I couldn't help but think the Helmholtz box was a part of that performance.
Burning Brakes
Joined: Jan 2006
Posts: 856
Likes: 74
From: Ave Maria FL
Pretty interesting, thanks for sharing your research. I would not have thought GM would have gone to that much trouble just for noise reduction. I think most agree the LS-3 intake system is pretty efficient and there is little to gain with aftermarket CAI setups. I couldn't help but think the Helmholtz box was a part of that performance.
Melting Slicks
Joined: Aug 2006
Posts: 2,866
Likes: 45
From: Tampa Bay, Go BUCS!!!Go Rays!!!Go Lightning!!!
St. Jude Donor '12-'13-'14
Interesting thread,,, first time in so many thoughts are bouncing around...
.....Maybe they don't do it on the LS7 because the owner/drivers aren't bothered by the extra sound. The car is supposed to be louder....
.....isn't the LS7 intake slightly larger? Maybe the extra volume is just as effective as the container on the side?.....
.....The MAF is a serious restriction to air flow in lower RPM ranges. Wouldn't this be more effective if it were connected directly to the intake manifold?.....
.....the BMW one in the exhaust sounds exactly like the technology they use in headers to scavenge the cylinders. Maybe that's why it adds power in the exhaust?.....
.....Maybe they don't do it on the LS7 because the owner/drivers aren't bothered by the extra sound. The car is supposed to be louder....
.....isn't the LS7 intake slightly larger? Maybe the extra volume is just as effective as the container on the side?.....
.....The MAF is a serious restriction to air flow in lower RPM ranges. Wouldn't this be more effective if it were connected directly to the intake manifold?.....
.....the BMW one in the exhaust sounds exactly like the technology they use in headers to scavenge the cylinders. Maybe that's why it adds power in the exhaust?.....
Safety Car
Joined: Dec 2004
Posts: 3,526
Likes: 18
From: Santa Fe TX
I know this is an old thread, but I wanted to add some real world experience. I purchased a H/C car with an LG carbon intake. This isn't a knock agains that specific intake, but a general observation aftermarket intakes without that resonator chamber.
after about 6 months with the aftermarket went ahead and put the stock intake back on.
While the resulting throttle response wasn't as "snappy" it also didn't surge or buck like before. I feel this is a result of the smoothing of the airflow. Got 1-2 mpg back too.
after about 6 months with the aftermarket went ahead and put the stock intake back on.
While the resulting throttle response wasn't as "snappy" it also didn't surge or buck like before. I feel this is a result of the smoothing of the airflow. Got 1-2 mpg back too.
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Le Mans Master
Joined: Jun 2011
Posts: 8,049
Likes: 329
From: Charlotte NC
St. Jude Donor '14-'15
I know this is an old thread, but I wanted to add some real world experience. I purchased a H/C car with an LG carbon intake. This isn't a knock agains that specific intake, but a general observation aftermarket intakes without that resonator chamber.
after about 6 months with the aftermarket went ahead and put the stock intake back on.
While the resulting throttle response wasn't as "snappy" it also didn't surge or buck like before. I feel this is a result of the smoothing of the airflow. Got 1-2 mpg back too.
after about 6 months with the aftermarket went ahead and put the stock intake back on.
While the resulting throttle response wasn't as "snappy" it also didn't surge or buck like before. I feel this is a result of the smoothing of the airflow. Got 1-2 mpg back too.
Burning Brakes
Joined: Oct 2001
Posts: 983
Likes: 23
From: Northeast Ohio
The way air flows in an engine isn't how most people thinks, it's a finite impulse wave, There's a good doc describing this (and more) here:
http://www.google.com/url?sa=t&rct=j...68235269,d.aWw
There are some interesting implications from this that involves port velocity, and the limit before pumping losses start increasing, ie changing stroke by itself doesn't make more power, it just changes the rpm of the torque peak, and since HP is a function of tq and rpm, it just changes the rpm (which could be better or worse for cam, intake and exhaust tuning). And if you can support higher rpm, you make more power because you have more combustion cycles. This is why small displacement F1 engines spin to 15,000 rpm plus, and make 700-800 HP. It's all very fascinating!
http://www.google.com/url?sa=t&rct=j...68235269,d.aWw
There are some interesting implications from this that involves port velocity, and the limit before pumping losses start increasing, ie changing stroke by itself doesn't make more power, it just changes the rpm of the torque peak, and since HP is a function of tq and rpm, it just changes the rpm (which could be better or worse for cam, intake and exhaust tuning). And if you can support higher rpm, you make more power because you have more combustion cycles. This is why small displacement F1 engines spin to 15,000 rpm plus, and make 700-800 HP. It's all very fascinating!
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
The "facts" in this thread are funny. 
Of course, the following statements wouldn't be so funny if they were coming from several different posters who had opposing thoughts, but you have to wonder when they're all from one guy.
"The key phrase here is that the pressure waves are essentially sound."
"I don't believe sound waves have mass therefore they don't affect the air velocity in the intake."
"I agree air has mass or hurricanes and tornadoes wouldn't be so devastating."
"I agree that sound isn't a "thing" but rather an interpreted response of our ears receiving a wave of compressed air"
"it (sound pressure waves) most certainly is real and has mass."
"I will see if I can get an explanation from GM technical help about why it was added to the C6 LS3 and deleted from the LS7 air intake."
"GM Global Technology patent number US7694660 B2 dated March 2008 for said device"
Could it be that the LS7 was introduced a couple of years before the patent was approved?
Of course, the following statements wouldn't be so funny if they were coming from several different posters who had opposing thoughts, but you have to wonder when they're all from one guy."The key phrase here is that the pressure waves are essentially sound."
"I don't believe sound waves have mass therefore they don't affect the air velocity in the intake."
"I agree air has mass or hurricanes and tornadoes wouldn't be so devastating."
"I agree that sound isn't a "thing" but rather an interpreted response of our ears receiving a wave of compressed air"
"it (sound pressure waves) most certainly is real and has mass."
"I will see if I can get an explanation from GM technical help about why it was added to the C6 LS3 and deleted from the LS7 air intake."
"GM Global Technology patent number US7694660 B2 dated March 2008 for said device"
Could it be that the LS7 was introduced a couple of years before the patent was approved?
Last edited by HOXXOH; Jun 4, 2014 at 01:22 PM.
Thread Starter
Racer
Joined: Nov 2013
Posts: 369
Likes: 2
The "facts" in this thread are funny. Of course, the following statements wouldn't be so funny if they were coming from several different posters who had opposing thoughts, but you have to wonder when they're all from one guy.
"The key phrase here is that the pressure waves are essentially sound."
"I don't believe sound waves have mass therefore they don't affect the air velocity in the intake."
"I agree air has mass or hurricanes and tornadoes wouldn't be so devastating."
"I agree that sound isn't a "thing" but rather an interpreted response of our ears receiving a wave of compressed air"
"it (sound pressure waves) most certainly is real and has mass."
"I will see if I can get an explanation from GM technical help about why it was added to the C6 LS3 and deleted from the LS7 air intake."
"GM Global Technology patent number US7694660 B2 dated March 2008 for said device"
Could it be that the LS7 was introduced a couple of years before the patent was approved?
Of course, the following statements wouldn't be so funny if they were coming from several different posters who had opposing thoughts, but you have to wonder when they're all from one guy."The key phrase here is that the pressure waves are essentially sound."
"I don't believe sound waves have mass therefore they don't affect the air velocity in the intake."
"I agree air has mass or hurricanes and tornadoes wouldn't be so devastating."
"I agree that sound isn't a "thing" but rather an interpreted response of our ears receiving a wave of compressed air"
"it (sound pressure waves) most certainly is real and has mass."
"I will see if I can get an explanation from GM technical help about why it was added to the C6 LS3 and deleted from the LS7 air intake."
"GM Global Technology patent number US7694660 B2 dated March 2008 for said device"
Could it be that the LS7 was introduced a couple of years before the patent was approved?
If you want to believe its for some other purpose in this application that's fine too. Lol
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
While it's true that the LS3 has the resonator, the LS7 was first available in the 2006 Z06, but the LS3 never arrived until the 2008 model year.
I personally am not concerned with the purpose of the resonator. I replaced mine with a Vararam for a performance gain, not for the sound of sucking air.
It's also worth noting that as of the time the LS9 (ZR1) became available for the 2009 MY, there were 3 different Donaldson filters. They each flowed a slightly different CFM and by virtue of having different amounts of filtering media, they also filtered different amounts of dirt before their life cycle ended.
Safety Car
Joined: Dec 2004
Posts: 3,526
Likes: 18
From: Santa Fe TX
That being said, the issue is still there, just not as bad.
Performance is no different, other than I can hear the valves now. Exhaust note is a bit different. Drone not as bad on "wild" mode.