Leave it at 0.5-0.6bar. The very long stroke and large bore of the 2.5 engine are a liability in the stock form of this engine, The engine itself would take a lot more boost in its stock form (1.1-1.2bar as long as you do not run out of injector) but it may not last. Actually it may not last very l...

Hello, I’m working on a Mazda MX-5 NC project. I’ve already installed a 2.5L engine from a Ford Fusion, and now I want to add a TD04HL turbocharger from a Subaru WRX. I’m aiming for 0.5 bar of boost to start with; the engine is completely stock, as is everything else—including the automatic transmis...