I have tanabe mufflers and ark hfc with stock everything else (sedan). Sounds great but I have some slight rasp or rattle sound on WOT from 3-3500 rpm. It's not obnoxious but I'd like to take care of it if possible.

There's no rasp at all when revving in neutral.

I was thinking a larger diameter y pipe may fix it but then my mid pipe would bottle neck.

Thoughts?

 

Is it rasp? Are your HFC's resonated? I vid clip would help. I had some "hiss" but the VQ motors produce that with HFC's. I had the FI's RHFC's.

 

They are resonated. Hard to tell from inside the cabin. I'll probably try to go with a larger y. Only be out a little money if it doesn't work. I think our stock y pipes are 1.75 ID at one end and 2.0 at the other.

 

I'll try and do a video clip with my phone while driving with the windows down but you can imagine how bad the quality will be

 

I would look into swapping the whole mid pipe like I did on mine