Our OEM intake uses a Helmholtz resonator as many do ... i was browsing the scooby forums for some things regarding my gfs car when i came across this thread:

A Problem with CAI/SRIs and an Alternative (yes, finally) - NASIOC

curious on if anyone has checked their MAF voltage to see if we get any sort of resonant spike at a certain RPM range. They get it between 1000rpm and 1800rpm.

Now sure, this can probably be tweaked with the AP should it affect us, but S2 owners may want to be aware until the tuning software that is being tested is fully refined.

(fyi i put this in gen-auto because it may not apply to us, in which i will delete to no confuse others)

 

1-1800 k rpm? cant see that even effecting us.

who is more than pulling out with thier 8 at under 2k rpm?

 

well sure their spike occurs at that rpm but I meant the actual theory behind it. If ours does it it would more than likely happen at higher rpms.

I have some logging software with me today.... on my way home I am going to log some readings like maf voltage and such to see what it looks like with the AEM intake.

 

isn't resonance the concept while the resonator is an implementation? That's how i perceived it, but thanks for the correction!

Just an update on this though: Here is a plot of my RPM to MAF voltage. Not scientific by any means, but the pulls were WOT, with no noticeable jitter.

 

Okay, but is your plot with a stock intake, or with an aftermarket intake that removes the resonator box?

You don't see a spike until you use an aftermarket intake without the resonator, according to the Subaru forum, and you are under high load low rpm throttle.

BC.

 

Using AEM intake with the last bend chopped off.