Will dremmeling out the inside of the stock air box help performance wise? I'll be installing my Spoon intake duct tommorow, and have the Spoon drop-in filter installed.

Thanx,
Chris

 

It certainly wont hurt. I did it after about 4000 miles with the duct and I can say I like it better with the box gutted. Just be sure to also remove the L shaped thingy on the top of the lid as well. Spoon recommends doing all this as well as blocking off the chamber just below the intake hose (make sense?).

After doing all this the biggest thing I noticed was a pleasant increase in sound. Not obnoxious, just "nice". My recommendation would be to install your duct, then see if you want to remove the internals.

 

I think it may or may not help from a performance perspective.

Most OEM boxes are there to reduce intake noise, that is true. But they also can be tuned to produce more midrange torque, and gutting them can actually reduce it a bit, while proving perhaps a hair more perf at the very highest RPM. A tuned resonacne intake tract can actually be made to flow more air at specific points by forming a tuned resonance circuit, similar to the benefits of having a carefully tuned pulse alignment in the exhuast airflow. The basic engineering principles are the same.

I have an engineering study from Volvo that shows this clearly - the stock airbox made about 5 ft/lbs more torque in the midband than did an open intake.

BTW, the engineering principle is based on the Helmholtz resonance equations, done by one of the pioneers early in the 20th century.

 

I dremeled mine days after buying the car and compared Tazzo runs. Netted 3hp but RR makes a good case for "tuned" resonances. It's not always the best solution to attach a simple pipe with a filter attached unless peak hp is your primary concern. The stock airbox is primarily designed for sound control and I have no doubt aftermarket intakes provide for more horsepower but the single best modification you can to your OEM unit is get a direct path of air to it either with a snorkel or ducting.

 

Well needless to say, I wrote the post the same day I did the install and didn't get enough replies before I did it. So we gutted the box, and installed the snorkle. I love it. There's no resemblance to the sound of a cai (rumbling sound) and all you can hear is air being sucked up. Sort of like a strong breeze

Chris