Primary Clutch Springs are all about resistance. The higher the resistance, the higher the RPM engagement. Low Engagement springs are designed for smoother takeoffs and more feasible for trail riders who vary speeds constantly. High Engagement Springs, like our Shift-Tek Silver Spring, are more desired for racing and drag set-ups. This High Engagement spring was designed and tested to increase engagement to about 2200 RPM when used with Stock Clutch Weights, compared to the stock spring with an 1800 RPM engagement.
If you plan on upgrading to the EVP Exclusive 2-Step Launch Control, we recommend our Shift-Tek Essential Clutch Kit which pairs this High Engagement Silver Spring with notched weights for an RPM Engagement of about 2600.
The EVP Shift-Tek Silver Spring, when used with stock clutching will net about 2200 RPM Engagement, which is high enough to use for our EVP Launch Control programming, but we recommend our Shift-Tek Essential Clutch Kit or which pairs the High Engagement Silver Spring with notched weights for an RPM Engagement of about 2600. We also offer our Ultimate Clutch Kit which also includes a Helix.