Hi all,

Thank you for all the answer and helps for the bogging issue of the IDM Evo3 .21, We have finally solved the bogging issue for this engine, After we have tried so many solution like tuning, clutch setting, head shim + and -, plug and fuel etc etc.....

The answer and the only solution the get rid of the bogging is related to the clutch system depending on what car are you on it, for us serpent 960 we have to cut the 3 pcs of centrifugal shoe without insert the shoe into the flywheel pin but just to lay in there between the pins which to make the centax to engage or disengage faster when rpm is reduce.. by this will eliminate the bogging issue. Serpent owner also can use the optional parts (Ser 903199). Good luck and happy racing.

By the way....
Our clutch setting for 960 is .6mm gap, .1mm clearance, 1.8mm spring preload with hard long spring.