It all depends on what setup/turbo and boost you are running that will enhance the sound of the valve and the chatter. I own the tried and tested Blitz SS (trumpet) on a standard ct9 and it sounds decent (short, tight and sweet), an all rounder. Paid £50 in decent condition. Many will also recommend the HKS SSQV series. Both are the most commonly used. You will find quite a few sound bites on youtube, well worth a look. Joz