Question: Different racers get different boost readings often from similar blown engine combinations. Why do some get that high boost reading and others do not?
Answer: Boost reading is also a function of the fuel split. Fuel split is the amount of fuel delivered to the blower hat injector versus the amount of fuel delivered to the intake manifold. That amount of fuel split determines the amount of cooling in the manifold. More fuel in the hat causes more cooling. That causes a denser mixture which then causes a lower boost. It then causes a lower boost reading and not necessarily less horsepower as many are finding out. A lot more information about fuel split is provided in 5000 Horsepower on Methanol. More information about boost readings is in Fuel Injection Racing Secrets.