I have HKS Hi-Power Spec-L
- Lighter than all quiet options listed here (22 lbs). About 20lbs lighter than stock
- Has the Helmholtz chamber like Thermal, plus resonator unlike Thermal
- Two options: Titanium and Carbon tip
- But it has dual canister design unlike the stock
- Louder than most options here (carbon fiber tip is a little heavier but quieter) but not enough to wake up neighbors. I have Ti tip and it is 93 db which below the legal sound limit in CA and NY.
See the link below
http://www.ft86speedfactory.com/hks-...eight-667.html