Hi, I just bought a Evo and i've heard that replacing the intake with a KN filter and adapter lowers the HP of the Evo? Is that true? I am thinking have that mod done to my car...any information would be greatly appreciated.

 

Just put the K&N drop in. If you use a Cone style with a new pipe, you will have issues with idleing and staggering unless of course you have it tuned for the intake.
You should be able to get away with the drop in and pick up some horse and throttle response and have no issues.

 

no, just get a adapter plate and cone filter and you will be fine. It actually adds like 3awhp, its the whole intake systems that can cause problems

 

adapter plate? got some examples?

Like it bolts onto the stock tubing and we're just using the cone instead of the box filter?

 

no typhoon!

 

My guess is that he is referring to the Apexi, which is only the filter and adapter plate.

If I was to go with an intake without a tune it would be the Apexi, from what I have gathered it's the new intake piping that can cause turbulence which throws off the MAF and leads to lean/idling conditions.

However if you are going with a tune, a nice smooth intake pipe could reveal some hp.

 

Don't put an intake, it will mess with you MAF sensor readings. If you want you can do a K&N drop in but be careful that you don't over oil it or it will coat your MAF sensor (bad). Do a search this has been cover before.