Cold Air Intake
JK Enthusiast
Joined: Jan 2008
Posts: 256
Likes: 0
From: SF, California
yep I agree with previous post.
I have K&N CAI and it looks good, better noise( at over 3000 rpm), power increased between 1hp and 8hp (depending your rpm: best would be 5000rpm), not so much mileage improvement as I have a 6speed and i shift around 2500 rpm on freeway (65mph at 2000 rpm in 6th gear).
I have K&N CAI and it looks good, better noise( at over 3000 rpm), power increased between 1hp and 8hp (depending your rpm: best would be 5000rpm), not so much mileage improvement as I have a 6speed and i shift around 2500 rpm on freeway (65mph at 2000 rpm in 6th gear).
JK Enthusiast
Joined: Feb 2007
Posts: 348
Likes: 0
From: Michigan
A conversation about this subject led to some tests with a pressure transducer on another board I am a member of. It was found that at WOT high RPM that there was only 0.5 inHG difference in the pressure in the intake and atmospheric pressure. Do some math on the VE of the engine with or without that pressure drop. You discover that a free flowing intake is only worth about 1.5 HP max, and only when the throttle plate is less of a restriction than the upstream intake. And this only applies if the real restrictions are parts you "fix" with your new parts.
There is also a similar equation you can use to determine the MPG increase at cruise assuming the same pressure drop reduction (even though it isn't an issue at cruise anyway). You get 0.34 MPG from the same hardware.
Assuming that you really did get colder air (unlikely) you can get another 0.23 hp by reducing the air temp by 12 degrees F.
I think the analysis that they are louder is really the only quantifiable difference.
A joke: How do you know when the JK MPG dash indicator is lying? When there are numbers shown on it.
There is also a similar equation you can use to determine the MPG increase at cruise assuming the same pressure drop reduction (even though it isn't an issue at cruise anyway). You get 0.34 MPG from the same hardware.
Assuming that you really did get colder air (unlikely) you can get another 0.23 hp by reducing the air temp by 12 degrees F.
I think the analysis that they are louder is really the only quantifiable difference.
A joke: How do you know when the JK MPG dash indicator is lying? When there are numbers shown on it.
JK Enthusiast
Joined: Jun 2007
Posts: 178
Likes: 0
From: Richmond Hill, Ontario
I think any intake is actually a good buy. I have the AEM, but honestly Airaid, k&n,aFE, AEM or whatever the one, they all do the same, sound the same. Personally i dont have mods other than intake, so i really do feel i big difference NOT in hp gains, but in throttle response and initial takeoff. Put those two things together and it makes you THINK that you hp gains. But no, just alot better response and noise sounds really nice lol. I think its worth it also if your planning intake + exhaust aswell becuase it goes hand in hand with better exhaust. My 2c