The bigger the spring, the stiffer it is and the later in the RPM range the clutch will engage. The smaller the spring, the softer it is and the earlier in the RPM range the clutch will engage. Common across all the Kyosho Inferno series of 1/8th scale RC Nitro Cars from the MP7.5 series to the MP777's and MP9. These are the Stock Spring rate for the clutch.
This product was added to our catalog on August 14, 2005