K&N CAI

[HarleyPat]

So if I add a K&N CAI to the car will I have to retune it? Car has dual mode exhaust.

[Two Fangs]

To see the most out of it, a tune would likely be necessary, but if it doesn't idle rough or throw a check engine light, ought to be fine otherwise. Folks have reported mixed success in that regard.

[HOXXOH]

So if I add a K&N CAI to the car will I have to retune it? Car has dual mode exhaust.

K&N doesn't make a CAI for the C6. They do make a filter and filter box to replace the OEM and claim it's a CAI.

Unless you draw ambiant (Cold) air into the engine, it's just a filter change.

See the chart on post #22. http://forums.corvetteforum.com/c6-t...nner-is-2.html

The human eye can only see particles about 40 microns and larger, so maybe this video of a filter manufactured in the same method and using the same materials as the K&N comparing to a filter using the same materials as the OEM, will show some visual ideas of what engines ingest. http://www.youtube.com/watch?v=HAoPha-hGpc

One more simple relationship between humans and LS3 engines. The engine breathes as much air in one minute at idle speed as the average adult breathes in 4 hours. Ever notice, if you wear a face mask for any reason due to the dust in AZ, how dirty it gets in less than an hour?

[Two Fangs]

So if I add a K&N CAI to the car will I have to retune it? Car has dual mode exhaust.

K&N doesn't make a CAI for the C6. They do make a filter and filter box to replace the OEM and claim it's a CAI.

http://www.knfilters.com/search/product.aspx?Prod=63-3073

Looks like it draws air from the same place as factory to me....

***EDIT***

I'm agreeing with Tom on this, since apparently my posts are cryptic at times...

[Big Poppa]

So if I add a K&N CAI to the car will I have to retune it? Car has dual mode exhaust.

K&N doesn't make a CAI for the C6. They do make a filter and filter box to replace the OEM and claim it's a CAI.

Unless you draw ambiant (Cold) air into the engine, it's just a filter change.

See the chart on post #22. http://forums.corvetteforum.com/c6-t...nner-is-2.html

The human eye can only see particles about 40 microns and larger, so maybe this video of a filter manufactured in the same method and using the same materials as the K&N comparing to a filter using the same materials as the OEM, will show some visual ideas of what engines ingest. http://www.youtube.com/watch?v=HAoPha-hGpc

One more simple relationship between humans and LS3 engines. The engine breathes as much air in one minute at idle speed as the average adult breathes in 4 hours. Ever notice, if you wear a face mask for any reason due to the dust in AZ, how dirty it gets in less than an hour?

And that is why I won't run a gauze style filter. If more air can get in through the same dimension filter, more dirt can get in too. Period. The hp gain from a gauze filter is very minimal anyway. Leave the factory airbox and paper filter in place, IMO.

[corvettech]

I like air raid filters personaly the element is thicker than a k/n and all around more robust but i dont run it for performance, i run it because im cheap and dont like buying new filters every 5000 miles

[HOXXOH]

I like air raid filters personaly the element is thicker than a k/n and all around more robust but i dont run it for performance, i run it because im cheap and dont like buying new filters every 5000 miles

You must have meant 50,000 miles, because that's what the OEM Donaldson Powercore filter in your '08 is rated for.

[Ted Y]

So if I add a K&N CAI to the car will I have to retune it? Car has dual mode exhaust.

K&N doesn't make a CAI for the C6. They do make a filter and filter box to replace the OEM and claim it's a CAI.

Unless you draw ambiant (Cold) air into the engine, it's just a filter change.

See the chart on post #22. http://forums.corvetteforum.com/c6-t...nner-is-2.html

The human eye can only see particles about 40 microns and larger, so maybe this video of a filter manufactured in the same method and using the same materials as the K&N comparing to a filter using the same materials as the OEM, will show some visual ideas of what engines ingest. http://www.youtube.com/watch?v=HAoPha-hGpc

One more simple relationship between humans and LS3 engines. The engine breathes as much air in one minute at idle speed as the average adult breathes in 4 hours. Ever notice, if you wear a face mask for any reason due to the dust in AZ, how dirty it gets in less than an hour?

And that is why I won't run a gauze style filter. If more air can get in through the same dimension filter, more dirt can get in too. Period. The hp gain from a gauze filter is very minimal anyway. Leave the factory airbox and paper filter in place, IMO.

I only kinda understand what you are saying, but I disagree about this blanket statement. I think you're making an assumption that the openings are uniformly distributed in a paper filter and a gauze filter.

Think of it this way, lets take a paper filter that has holes small enough to effectively filter out small dirt that can harm an engine, but there are only 1000 holes per square inch. The air will pass through those holes and stop the dirt at a certain rate per given pressure difference across the filter. If a guaze type filter has more than 1000 holes, but they are still small enough to stop the dirt particles (same as paper) it will flow more air and still effectively filter per the same pressure difference.

They are different media with different properties. I have no problem believing a gauze type media can filter the same as paper yet flow more.

Thoughts?

[fourseventeen]

I was running the K&N CAI on my 2007 C6/Z06 and didnt retune. I noticed a power increase and I didnt have any check engine light issues or anything.

[HOXXOH]

So if I add a K&N CAI to the car will I have to retune it? Car has dual mode exhaust.

K&N doesn't make a CAI for the C6. They do make a filter and filter box to replace the OEM and claim it's a CAI.

Unless you draw ambiant (Cold) air into the engine, it's just a filter change.

See the chart on post #22. http://forums.corvetteforum.com/c6-t...nner-is-2.html

The human eye can only see particles about 40 microns and larger, so maybe this video of a filter manufactured in the same method and using the same materials as the K&N comparing to a filter using the same materials as the OEM, will show some visual ideas of what engines ingest. http://www.youtube.com/watch?v=HAoPha-hGpc

One more simple relationship between humans and LS3 engines. The engine breathes as much air in one minute at idle speed as the average adult breathes in 4 hours. Ever notice, if you wear a face mask for any reason due to the dust in AZ, how dirty it gets in less than an hour?

And that is why I won't run a gauze style filter. If more air can get in through the same dimension filter, more dirt can get in too. Period. The hp gain from a gauze filter is very minimal anyway. Leave the factory airbox and paper filter in place, IMO.

I only kinda understand what you are saying, but I disagree about this blanket statement. I think you're making an assumption that the openings are uniformly distributed in a paper filter and a gauze filter.

Think of it this way, lets take a paper filter that has holes small enough to effectively filter out small dirt that can harm an engine, but there are only 1000 holes per square inch. The air will pass through those holes and stop the dirt at a certain rate per given pressure difference across the filter. If a guaze type filter has more than 1000 holes, but they are still small enough to stop the dirt particles (same as paper) it will flow more air and still effectively filter per the same pressure difference.

They are different media with different properties. I have no problem believing a gauze type media can filter the same as paper yet flow more.

Thoughts?

Let's take the math and physics path on what you said.

1000 holes/sq" in paper vs >1000 holes/sq" in gauze and the hole diameter is the same size on each.

The simple logic is that a greater number of identical size holes will allow greater flow, which is true. But now for an air filter, the construction requires a method that is compatible with the material type, the physical space, the particle size to be filtered, and the airflow needed.

First thing is to figure how much air you need. A 427 engine at 7000 RPM at 100% efficiency pulls in 865 cu ft per minute (CFM), but depending on a number of factors can increase that to ~1,000 CFM. If we assume the filter should be changed at that time to avoid any additional restriction, it will have to start its' life much higher. How much higher depends on the size and volume of particulates trapped in the average environment. For illustration purposes, let's just say double or 2,000 CFM.

Now if we limit the maximum allowable pass-through particle to 10 microns the media fibre size will control how many holes we can create per square inch. For instance, if the fibres were .50 and placed in a standard X-Y configuration, you could only achieve 1 hole per square inch. The cotton fibres in a K&N style cotton gauze mesh are 50 microns wide on 500 micron centers, the steel wire mesh size is 250 micron on 1500 micron centers. There were two layers of cotton gauze mesh in the filter I tore apart to do these measurements. Now in a perfect world to get the best filtration, those layers would be offset on both the X and Y axis by half the increment. So disregarding the steel mesh, which stops sticks and stones and holds the gauze in place, we can subtract 50 microns for the intermediate fibre from the 450 micron opening and divide by two to get the opening size for the overlapped cotton mesh. The best possible result is a 200 micron square.

How the K&N style is able to stop those 200+ micron particles is by pleating the mesh to gain enough total surface area to allow the volume of air needed within the confines of the container/airbox. The pleating forces the air to go through on an angle, rather than straight. Since the particles tend to float around in a low speed airstream, the filtration is worse at low engine speeds than at WOT where the particles are driven into the mesh at a low angle. Oiling the cotton is the main method of capturing the particles. Unfortunately, re-oiling after the first cleaning, never distributes the oil evenly in the pleats.

The paper filter media in contrast has smaller fibres (around 10 micron) and they are randomly placed (no mesh) within a thick layer that allows a larger number of smaller randomly shaped openings. These filters are also commonly pleated, but are able to trap smaller particles at low airflow rates due to the smaller openings.

A filter does the poorest job of filtering when it's clean, but the best job of allowing maximum airflow.

Oh crap! You only wanted thoughts. OK try this: K&N sucks and paper is better. Watch the video again.

[ChadC]

these are the bomb High filtration, High flow, and they last 60K+ miles http://www.donaldson.com/en/engine/support/datalibrary/059806.pdf