I recently purchased a set of manley turbo 9:1 pistons for a k24a4. i was told by manley to use their formula. i first had to convert 87mm into inches. formula below. it seems to me that the gap is way to small for a boosted motor. their gap is even smaller than the oem recomendations by honda. the motor will be built. the turbo will be either a gt3782 or a gt4088. my car is also a daily driver. i plan on running 8-12lbs on the street and 18-25lbs on the track. this is the last bit of info i need to finish building. thanks

bore (87mm) divided by 25.4mm= 3.4252"

3.4252 x .0045= .015 (top ring)

3.4252 x .0035= .012 (bottom ring)

 

The top ring gap sounds about right, but usually the second ring gap needs to be bigger than the top.

 

so then if thats the case. i should just go with oem specs.