How to modify a verto type clutch to handle high torque engines, from two clutch units, known as the RTS richard twin spring after the guy that came up with the idea. This uses two clutch springs to give more clamping force on the clutch plate. This is a cost effective way to upgrade your verto type clutch for supercharging, turbocharging or twin cam etc. Easy DIY mod involving drilling out rivets and some tapping . M8x20mm allen button head bolts required around £5 for 20 bolts with washers.