That HPC coating isn't too dear to have done. (At least here in NZ) I had the (EE5) slugs for my most recent A15 build done, but the engine is barely run in, so I can't say if it's made any real improvement yet.

Aftermarket pistons suppliers do a lightweight A15 flattop. Arias do custom pistons.

mmm ca16de didnt think of that, im sure one of the aftermarket suppliers will do a light flattop piston. i was thinking of getting them hpc coated on top and teflon coated on the skirt to reduce the heat and friction of them too

Some guys here in NZ run CA16de rods, and mazda MX5(?) pistons. The CA rods use a floating 20mm pin, and 9mm rod bolts. They are much beefier than the A15 rods, but lighter than the CA18 rods.

hi guys im rebuilding my ipra coupe A15 at the moment and just what to see what combination pistons and rods you have heard of. i havnt pulled mine down as of yet, i will do that before the weekend and will take some photos of my setup atm so i can try to identify what they are, from what ive been told its a shot peened A15 rod with a resized little end to suit the 20mm mazda flat top setup.
has anybody tried and motorbike piston and rod setups, im going for lightweight rotating assembly and am just trying to find out whats been done.
im not asking you to tell me what you run, im just asking whats been done because my boss basically only deals with ford and holden v8s and has no real idea on current 4 cyl technology, his hay day was spent with datsun 1600 l series donks but.
any info will be greatly appreciated, thanks kurt