hey hi, take a look at my mods, its pretty extensive, but something dosent make sense... i have a Hayame exhaust with 2.5" custom cat back. It has a GREAT deep tone, yet, i recently installed the SR 4-1 headers.. oh hell yea!! GRET TORQUE AND hp INCREASE and louder deep tone from my exhaust, but also a high pitch rattle or zip sound, like a bumble bee effect.. only at certain RPM levels.. i hate it!! i thought it was that i blew the exhaust internally, maybe a baffle? and the welder found some pin holes in the cat piping, so he rewelded it and it took out some of the high pitchness... but there still is some, and everyone is telling me now that i have alot more air flow i have to deal with it... my gut feeling is that its the exhaust internally, but damn, where i bought my Hayame, they say its the same reason, lots of flow, but i really dont think so, casue the more i run the car, the hotter it gets the sound goes away.. i dunno.. should i try another exhaust??

 

This is happening to be also. and check out my sig. for my mods. I've been told a glasspack "should" kill the weeeeeeeeeeeeeeeeeeeeeeeeeeeeee noise. so I went today and was gonna get a glasspack..but all they had was a OVERALL 28" glasspack. and I thought that was quite a little to big. As I've "been told" to get an 18"-22" . but I think im am going to go get that 28" glasspack tomorrow and get it a whirl...it's onlt 15.00 so if it doesn't work im only out 15.00 (and the cost of install.....any thoughts...?

 

As I mentioned in you other thread, if you put 28" glasspack, that could really make your car quiet barely noticeable while accelerating. It all depends on personal preference, but if you want performance sound go with 21-21" glasspack (try online store for Dynomax glasspack for 2.5" inlet/outlet. It is better desgined than Pepboy cherry bomb muffler).

Oh yeah, put glasspack to kill annoying vibrating noise.