Will_da_beast

Hey folks first post here so take it easy on me. I own a nicely modded street NA8 94. My motor is getting tired it' runs well it just isn't very exciting any more. Did a compression check low 140's. So I'm looking to do a rebuild or buy a low mile Bp5a 6 speed swap. I'm here in Cali so CARB/ will be running (at least for now) stock ECU. My thinking and I can be wrong, Usdm NB1 (have one) intake mani, NA8 injectors and rail, stock timing and CAS. I'm I on the right track? I'm un sure of the bp5a's compression 9.5:1 or 10:1. We only have 91 Oct hear so theres that. Should still pass emissions? thank you for any advice

my97miata

I believe the BP-5A engine has 9:1 compression ratio because it is the turbo engine. The 99-00 engines have 9.5:1 and the 01-05 VVT engines have 10:1 compression ratios.