Wastegates - Facts and Fiction

With so many contradicting opinions and recommendations, it’s a little wonder choosing the right Wastegate for your application can be a confusing.
We try to disspell some myths and shed some light on the most common misconceptions regarding wastegates.

TRUE OR FALSE
*The more powerful the engine, the bigger the wastegate you need.*
False. This is one of the more popular misconceptions. A wastegate is possibly the only component in your whole engine package that can actually be made smaller as you increase your boost/horsepower output. Use this simple guide:
Big Turbo/Low Boost = Bigger Wastegate
Big Turbo/High Boost = Smaller Wastegate
Small Turbo/High Boost = Smaller Wastegate
Small Turbo/Low Boost = Bigger Wastegate

Wastegates don’t operate in high temperatures
False. Contrary to the popular belief, external wastegates are usually mounted at the hottest part of the exhaust. It’s the place where all the exhaust gases meet, creating extra heat. This, combined with the late combustion of unburnt fuel (due to rich mixtures, retarded timing and high octane fuels) significantly raises the exhaust temperature.

Larger wastegate valve diameter = better flow
True – sort of. While the valve diameter is without a doubt an important part of the flow rate, equally important, but often misunderstood, is the importance of the flow path. When comparing wastegates with similar valve size, it is important to have a balanced body/valve/spring combination that is designed to work together to allow for maximum boost control. All Turbosmart wastegates are designed with this in mind.