Methanol injection

How do you tune a car running pump gas with methanol injection to decress the combustion temp, and what are the common limits of doing so?

There isn't a single way of doing this so it's hard to be specific in answering. Most often people would use a water/methanol injection kit to do this but it's also possible to use a secondary fuel system with its own set of injectors to inject pure methanol under high boost and rpm. This second method requires an ECU capable of running a dual fuel system though to get seamless results. For the first method there are a variety of off the shelf WMI kits available. You can check out a webinar we did on WMI here: https://www.hpacademy.com/previous-webinars/069-watermeth-injection-tuning-motec-m150/