FWIW, I spun these dual springs to 11.5k RPM…
skunk2.com
311-05-7350 - Springs, Retainers & Bases - Engine - Skunk2 Racing
<p>Skunk2 is proud to introduce its Pro Series XP (Extra Pressure) Racing Valve Spring Kits for the Honda B16/ B17/ B18 VTEC engines. Each kit includes Skunk2’s high-quality race-proven dual valve springs that are the result of nearly two decades of