What issue is it that you're trying to fix in PCars, the steering lock or the engine vibration?Any idea if something like this would work in Project Cars 2? This fixed the steering issue I've had in every Madness Engine game I'm curious of this could be done for that game too.
The specific tweaks I've used here should work since the sims are on the same engine, but they may not. While custom files allow us to tweak the FFB between the sim and our wheels, they don't allow us to change how the sim itself is creating forces. That's the bit which is different between the sims, so these fixes may depend on how different the Reiza/SMS FFB implementations are.