So the other day I noticed a sound coming from somewhere in the car. It sounds like under the car but my friend also said it sounds like the around the engine. It only happens around 1400-2100 rpms in every gear. But it only happys when I let up around that or sometime around when I shift at 4k. It makes a "Tsssst" sound. Sometimes long and other really short. I put a video for reference. I just recently put in thr alta air intake and a OBX Catless Down Pipe and deletes the resonator. And only started to happen after the downpipe and resornator delete. https://youtu.be/slRwd2Bdk6M Sent from my LG-H830 using Tapatalk
Sounds like a heat shield rattle to me, get the car up in the air and bump the exhaust with a rubber mallet till you can locate the source of the sound.
Not sure myself. I have the Alta intake and a Miltek exhaust, but I did have a heat shield rattle that was pretty easily taken care of before the two of those mods happened. I will say that the Alta intake does make for a much louder whoosh and blow off when under load, though you'll have to be lugging the engine a bit to hear it. I did also get a GFB diverter valve which reduced that somewhat. I'm not sure that's what I'm hearing though, so look at the heat shield first.
It is hard to tell from that clip, but to me, it sounds like the diverter valve releasing pressure. That would be a normal sound. Without actually standing next to the car, that's the best response I can give. CD