Positive Displacement Applications
1. Pre-Throttle Body/Carburetor Injection
On EFI/carbureted positive displacement applications, pre-throttle body/carburetor water methanol injection evolves positioning the nozzle or nozzles just before the throttle body or carburetor. This is by far the most common location for EFI positive displacement applications. While carburetor applications commonly injected under the carburetor. See post-carburetor injection below for details.
A common question that often comes up from customers, "Is it safe to inject into the inlet of my supercharger?". Absolutely. In fact, by injecting a water methanol mixture into the inlet of your positive displacement roots or screw style supercharger, not only can we lower discharge air temperatures, we can also lower internal supercharger temperatures and improve supercharger efficiency. The water methanol injection works to help seal the tight clearances between the rotors and the housing improving supercharger efficiency. As many times the supercharger are operating in dry conditions such as EFI applications which have the injectors placed after the supercharger. This is one advantage of having a carburetor mounted above the roots or screw style supercharger as the gasoline has a similar effect.
Another advantage to pre-throttle body/carburetor injection is there is no need for running multiple smaller nozzles to increase atomization on larger output engines. Since the fluid has to physically pass through the superchargers rotors, a single larger nozzle will work just as well as two smaller nozzles compressing of the same output as the one larger nozzle. The result is the same coming out the bottom of the supercharger./
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