After running 110mm velocity stacks (trumpets) for almost 2-years I decided it was time to try a set of 100mm stacks instead, in an effort to gain more clearance between the clutch master cylinder and gain slightly more top-end power. So after a short wait these shiny new billet velocity stacks arrived from Australia, made by SQ Engineering. Let me start by saying that the build quality of these are AMAZING. They're machined from a single piece of aluminum alloy and this set is designed especially for the 20v Blacktop. For anyone who'd like to watch a set getting made (50mm shown in the video) check out this YouTube video: Machining of Billet Velocity Stacks - YouTube
I now have more clearance between the #1 stack and the clutch master cylinder, the sound they emit doesn't sound so raspy like my old ones due to the much thicker alloy construction (spun vs billet) and the pull from 6,000rpm-8,500rpm is noticeable stronger than my previous 110's. You sacrifice a little bit of earlier/low-end power due to being 10mm shorter in length, but it more than makes up for it in the top-end. As an added bonus, these new stacks are incredibly shiny and resist scratches and fingerprints really well. If anybody wants a set, contact SQ Engineering on Facebook or through the website as they do a number of different sizes for both the Silvertop & Blacktop engines, and also offer an equally impressive spun/rolled type for slightly less $$$.