[ANSWERED] Cold Air Intake
10-13-2016, 10:22 AM
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[ANSWERED] Cold Air Intake
The original question is here.
Rookieracer asked:
It seems like the aftermarket industry has found quite a lot of power with the various cold air intake systems. More than I would normally think possible on a modern day hot rod like the Z06.
Would you please share your thoughts on the possible restriction of the air intake system on the Z06 models versus the base models?
It seems like the aftermarket industry has found quite a lot of power with the various cold air intake systems. More than I would normally think possible on a modern day hot rod like the Z06.
Would you please share your thoughts on the possible restriction of the air intake system on the Z06 models versus the base models?
Tadge answered:
The induction systems for the Stingray, Grand Sport and Z06 are essentially identical. The only difference is that the supercharged engine has an off-center location for the throttle body that necessitates a different plumbing geometry downstream of the filter. Although one person on the thread speculates that we commonized the filter elements to save money, that is certainly not the case. We engineer all Corvette intake systems for minimum restriction and to meet many other requirements that aftermarket companies do not.
We do not routinely test aftermarket induction systems or any other aftermarket parts for that matter. We have our hands full designing, building and testing our production hardware. Although simple in concept, induction systems play an important role in many vehicle performance areas. Aside from the exhaust, there is no greater noise source on a performance vehicle. Induction systems generally have many tuning elements that ensure the quality of the sound emanating from it are pleasing and harmonious with the exhaust note. These tuning elements also dampen the sound energy to help with pass-by requirements. Aftermarket companies don't have to worry about it, but as the OEM, we must guarantee that our products are quiet enough to be driven at full throttle by a microphone by the side of the road and meet certain decibel levels. There are pass-by laws in many states and pretty universal around the world.
Another important element in the induction system is the mass air flow sensor or MAF. Engines can only run at their optimal efficiency if they have very precise data on the amount of air flowing into them. Although most people think of air flow into an engine as fairly continuous, it really is not. The opening and closing of valves and reciprocating nature of internal combustion engines means the air flow is really a series of pulses which make measuring the exact flow challenging. Intake engineers spend a lot of time optimizing the system to get excellent signal quality out of the MAF. In addition to efficiency, or fuel economy, the precise metering of air and fuel is directly correlated with tail pipe emissions, an area of extreme scrutiny by government agencies for we manufacturers.
There are some other areas of intake design that you might not think about right away such as water fording. We do tests where we drive the car at various speed through water troughs of depths between 2 and 12 inches. Most customers would never dream of doing such a thing, and, although I don't recommend it, we take due care to make sure the engine does not ingest water. In fact, as we get to the end of the trough, we go wide open throttle to maximize the suction into the engine. In case anyone is puzzled about why this is important, when an engine ingests water into the cylinder, it can hydro-lock resulting in complete engine failure. Most customers would return to the dealer and ask for engine replacement under warranty. This is one of the reasons installation of aftermarket intakes can void your powertrain warranty. In addition to water fording we do validation testing for extreme rain, snow and dirty environments.
Besides needing to be fed dry air, the induction system needs access to cool ambient air. This is why we breathe into a space behind the headlamp and under the right fender. The air inside the engine compartment is generally much warmer and, even though a larger, lower restriction filter could be packaged there, the hot air ingestion outweighs the filter restriction in terms of real world performance. Now some companies might make this choice and then optimize the dyno set up to minimize the effects such as running with the hood open or a strategically placed external fan. I have no specific knowledge about how the aftermarket companies operate, but I do know that dynos can be set up in many ways to demonstrate performance improvements that do not materialize in real-world driving.
The air filter itself is the focus of many discussions on low restriction. Its job is to keep foreign material out of the engine. Here again, there are many trade-off decisions balancing restriction with filter life (service interval) and filtration quality. Sacrificing either of the latter two improve the former. We tend to be conservative to make sure that our engines are very durable, so that does open up an opportunity for aftermarket system.
As with many of the questions on this forum, all vehicle design is a balance of trade-offs. We do what is legal and right for the vast majority of customers. Aftermarket companies offer products that strike a different balance that might appeal to some folks. I am appreciative of this opportunity to explain some of the thought behind the decisions we make.
The induction systems for the Stingray, Grand Sport and Z06 are essentially identical. The only difference is that the supercharged engine has an off-center location for the throttle body that necessitates a different plumbing geometry downstream of the filter. Although one person on the thread speculates that we commonized the filter elements to save money, that is certainly not the case. We engineer all Corvette intake systems for minimum restriction and to meet many other requirements that aftermarket companies do not.
We do not routinely test aftermarket induction systems or any other aftermarket parts for that matter. We have our hands full designing, building and testing our production hardware. Although simple in concept, induction systems play an important role in many vehicle performance areas. Aside from the exhaust, there is no greater noise source on a performance vehicle. Induction systems generally have many tuning elements that ensure the quality of the sound emanating from it are pleasing and harmonious with the exhaust note. These tuning elements also dampen the sound energy to help with pass-by requirements. Aftermarket companies don't have to worry about it, but as the OEM, we must guarantee that our products are quiet enough to be driven at full throttle by a microphone by the side of the road and meet certain decibel levels. There are pass-by laws in many states and pretty universal around the world.
Another important element in the induction system is the mass air flow sensor or MAF. Engines can only run at their optimal efficiency if they have very precise data on the amount of air flowing into them. Although most people think of air flow into an engine as fairly continuous, it really is not. The opening and closing of valves and reciprocating nature of internal combustion engines means the air flow is really a series of pulses which make measuring the exact flow challenging. Intake engineers spend a lot of time optimizing the system to get excellent signal quality out of the MAF. In addition to efficiency, or fuel economy, the precise metering of air and fuel is directly correlated with tail pipe emissions, an area of extreme scrutiny by government agencies for we manufacturers.
There are some other areas of intake design that you might not think about right away such as water fording. We do tests where we drive the car at various speed through water troughs of depths between 2 and 12 inches. Most customers would never dream of doing such a thing, and, although I don't recommend it, we take due care to make sure the engine does not ingest water. In fact, as we get to the end of the trough, we go wide open throttle to maximize the suction into the engine. In case anyone is puzzled about why this is important, when an engine ingests water into the cylinder, it can hydro-lock resulting in complete engine failure. Most customers would return to the dealer and ask for engine replacement under warranty. This is one of the reasons installation of aftermarket intakes can void your powertrain warranty. In addition to water fording we do validation testing for extreme rain, snow and dirty environments.
Besides needing to be fed dry air, the induction system needs access to cool ambient air. This is why we breathe into a space behind the headlamp and under the right fender. The air inside the engine compartment is generally much warmer and, even though a larger, lower restriction filter could be packaged there, the hot air ingestion outweighs the filter restriction in terms of real world performance. Now some companies might make this choice and then optimize the dyno set up to minimize the effects such as running with the hood open or a strategically placed external fan. I have no specific knowledge about how the aftermarket companies operate, but I do know that dynos can be set up in many ways to demonstrate performance improvements that do not materialize in real-world driving.
The air filter itself is the focus of many discussions on low restriction. Its job is to keep foreign material out of the engine. Here again, there are many trade-off decisions balancing restriction with filter life (service interval) and filtration quality. Sacrificing either of the latter two improve the former. We tend to be conservative to make sure that our engines are very durable, so that does open up an opportunity for aftermarket system.
As with many of the questions on this forum, all vehicle design is a balance of trade-offs. We do what is legal and right for the vast majority of customers. Aftermarket companies offer products that strike a different balance that might appeal to some folks. I am appreciative of this opportunity to explain some of the thought behind the decisions we make.
10-13-2016, 03:02 PM
#3
Melting Slicks
Great answer and information! To me an interesting and off-topic observation is that Tadge read the other comments on the thread. Nice to see that he reads those, especially after previously saying the team generally does not read the forum. I hope they do.
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SBC_and_a_stick (10-18-2016)
10-13-2016, 03:43 PM
#4
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I wouldn't count on him (or the team) randomly perusing the site though just looking for stuff.
10-13-2016, 04:28 PM
#5
Drifting
Great response Tadge. Thanks!
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Maxie2U (10-21-2016)
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Maxie2U (10-21-2016)
10-14-2016, 01:18 AM
#7
Le Mans Master
That is why based on his comments about factors other than just performance, such as water injestion, I went with the Callaway Honker. Knowing their work along with GM, I trusted their reputation and quality to be the best for me. Plus their after the sale concern is outstanding.
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Maxie2U (10-21-2016)
10-14-2016, 09:56 AM
#8
This is why after I bought my C6Z I decided the factory knows best when it comes to hot rodding. After 30 years of modifying my previous car (IROC-Z28), I decided the only thing I'll do to this car is just press the green button and go. I'm even keeping the air filter element stock. It seems every aspect of the Z is tightly engineered and well balanced with compromises in all the right areas. I can take it to a track, have some fun and it's comfortable enough to drive across the country.
And interesting side note. I recently drove my neighbor's 2007 Porsche GT3. As nice as it was, I didn't feel it was worth $32-35K over the MSRP of my Z. A testament to GM's engineering capabilities...just as long as their vendors don't seriously screw up....
And interesting side note. I recently drove my neighbor's 2007 Porsche GT3. As nice as it was, I didn't feel it was worth $32-35K over the MSRP of my Z. A testament to GM's engineering capabilities...just as long as their vendors don't seriously screw up....
Last edited by SHM; 10-14-2016 at 09:58 AM.
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Fastmikefree (10-21-2016)
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Maxie2U (10-21-2016)
10-15-2016, 07:51 PM
#10
Interesting comments on the OEM's thinking.
The drive-by road side microphone test and water fording especially.
I hear a lot of folks saying that OEMs know best, but they can also be limited by some severe standards that the enthusiast may not.
I for one like the throaty roar of an aftermarket intake and would never drive through deep water.
The drive-by road side microphone test and water fording especially.
I hear a lot of folks saying that OEMs know best, but they can also be limited by some severe standards that the enthusiast may not.
I for one like the throaty roar of an aftermarket intake and would never drive through deep water.
10-18-2016, 05:57 PM
#11
Safety Car
Excellent response from Tadge, with great insight many of us would never see elsewhere.
I've been using the OEM intakes/filters for 6 years in a row now. The top notch filtration alone is worthwhile.
Great to see Tadge reading beyond the first post as well!
I've been using the OEM intakes/filters for 6 years in a row now. The top notch filtration alone is worthwhile.
Great to see Tadge reading beyond the first post as well!
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Maxie2U (10-21-2016)
10-19-2016, 12:46 PM
#12
Team Owner
Interesting comments on the OEM's thinking.
The drive-by road side microphone test and water fording especially.
I hear a lot of folks saying that OEMs know best, but they can also be limited by some severe standards that the enthusiast may not.
I for one like the throaty roar of an aftermarket intake and would never drive through deep water.
The drive-by road side microphone test and water fording especially.
I hear a lot of folks saying that OEMs know best, but they can also be limited by some severe standards that the enthusiast may not.
I for one like the throaty roar of an aftermarket intake and would never drive through deep water.
I enjoy the obvious power increase. Over the stock intake.
IMO the car runs slightly cooler even just the intake Then esp with coated headers that get the huge hot cats out from under the hood and the coated pipes hold many times less
heat than the cast manifold parts and heavy gauge stainless steel holds as well and cool very quick. This you notice right away!
Gm could learn from the aftermarket as most aftermarket mods really improve the car over factory.
From brake pads to the intake to the shifter and everywhere in between.
My car is more fun to drive and is a better package. I would not pull the mods I have that's for sure and they were worth every penny.
10-19-2016, 03:31 PM
#13
Drifting
I enjoy the obvious power increase. Over the stock intake.
IMO the car runs slightly cooler even just the intake Then esp with coated headers that get the huge hot cats out from under the hood and the coated pipes hold many times less
heat than the cast manifold parts and heavy gauge stainless steel holds as well and cool very quick. This you notice right away!
Gm could learn from the aftermarket as most aftermarket mods really improve the car over factory.
From brake pads to the intake to the shifter and everywhere in between.
My car is more fun to drive and is a better package. I would not pull the mods I have that's for sure and they were worth every penny.
Greg
Last edited by UBNZO6D; 10-19-2016 at 03:33 PM.
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3 Z06ZR1 (10-19-2016)
10-19-2016, 04:09 PM
#14
Team Owner
I sure hope you're to go your raceway on the 29th and proving how much these mods have helped you...You predicted 135 and I was guessing 140 with your driving skills since you are up over 100 RWHP over stockers and M7's have gone 134.7 stock with only a tire mod...Good luck on the 29th, I'm rooting for you.
Greg
Greg
10-19-2016, 04:37 PM
#15
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C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Good answer, I'm aware the choices are always made as trade-offs and being able to drive it everywhere, but what interests me is the specific tests that cause them to go one way vs the other.
10-20-2016, 12:58 PM
#16
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St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
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Interesting comments on the OEM's thinking.
The drive-by road side microphone test and water fording especially.
I hear a lot of folks saying that OEMs know best, but they can also be limited by some severe standards that the enthusiast may not.
I for one like the throaty roar of an aftermarket intake and would never drive through deep water.
The drive-by road side microphone test and water fording especially.
I hear a lot of folks saying that OEMs know best, but they can also be limited by some severe standards that the enthusiast may not.
I for one like the throaty roar of an aftermarket intake and would never drive through deep water.
10-20-2016, 01:01 PM
#17
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St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
I enjoy the obvious power increase. Over the stock intake.
IMO the car runs slightly cooler even just the intake Then esp with coated headers that get the huge hot cats out from under the hood and the coated pipes hold many times less
heat than the cast manifold parts and heavy gauge stainless steel holds as well and cool very quick. This you notice right away!
Gm could learn from the aftermarket as most aftermarket mods really improve the car over factory.
From brake pads to the intake to the shifter and everywhere in between.
My car is more fun to drive and is a better package. I would not pull the mods I have that's for sure and they were worth every penny.
this is so true. I enjoy the concert played by my CAI along with my headers.
10-21-2016, 04:29 PM
#19
Good info!
Interesting statement: "We tend to be conservative to make sure that our engines are very durable, so that does open up an opportunity for aftermarket system."
This says to me there is more power to be had and aftermarket components may not be a bad thing or harmful.
Plus when you add:
"We do not routinely test aftermarket induction systems or any other aftermarket parts for that matter. We have our hands full designing, building and testing our production hardware."
Interesting statement: "We tend to be conservative to make sure that our engines are very durable, so that does open up an opportunity for aftermarket system."
This says to me there is more power to be had and aftermarket components may not be a bad thing or harmful.
Plus when you add:
"We do not routinely test aftermarket induction systems or any other aftermarket parts for that matter. We have our hands full designing, building and testing our production hardware."
