This insert has a lower volume / higher compression ratio than our VHM standard insert, meaning more low and middle range torque. This improves acceleration and gives an increased torque feeling when exiting corners. However, keep in mind that this compromises top speed. The combustion chamber fits the VHM cylinder head perfectly and is easy to change. The last numbers of the part number are engraved on the insert for identification.
Use in combination with VHM head AA33157
This insert does not fit into an OEM head, only a VHM cylinder head. It's recommended to use good fuel against detonation.