This turbo kit contains all the parts you will need to fit a turbo to a Mazda MX5 Mk1 1.8. The pipework has a flange for the 50mm Tial-type blow-off valves and a 3/8 NPT boss for an IAT sensor. For the BOV, there is a flange already welded into the intercooler pipework which accepts the 50mm Tial BOV.
eBay