A wastegate, or commonly known as an exhaust valve, is a pressure release system on turbocharged engines. It fits between the compressor and throttle output and reduces wear on the turbocharger as well as the engine by alleviating the damaging effects of the compressor. Allows compressed air to recirculate or vent to atmosphere by diverting pressurized air with the throttle closed.
To install it, the vehicle must have a turbocharger or supercharger. Exhaust valve kits are available for many models including Audi, Ford, Mitsubishi, Nissan, Subaru, and Volkswagen. Car manufacturers typically retrofit this for emissions purposes, as well as fuel economy and drivability.
Most people who install it aftermarket do so to get a higher boost level than stock, for better throttle response, and of course to make the exhaust hiss or hiss.
There are two specific brands of flush valves. Bailey Motorsport offers a piston-design wastegate, which has faster reaction time, higher boost capacity, and can work on cars with air flow meters. They sell the Bailey single piston dump valve or two piston if you are a noise lover. If you prefer a quieter drive, they offer the piston-type recirculating dump valve. Prices range from $83.00 to $118.00, depending on the style you prefer.
Forge Motorsport also offers a variety of wastegates. Forge maintains that its valves are designed and built with the intent to vent 100% of residual charge air to atmosphere. They have single piston and double piston valves, as well as offering a recirculation valve. Prices start at $138.00.
This can be equipped for several different modes. For example, a hose holder can be used, making it easy to replace, if necessary. A pipe mount can also be used by welding the base in position between the compressor outlet and the throttle. Vehicle specific flange adapters are also available.
Installation of a flush valve is a personal preference. Some people, mainly car enthusiasts, love the hiss and hiss that occurs when air is released into the atmosphere. Others feel that there is no benefit to vehicle performance and after a while the noise becomes annoying. It requires a certain amount of maintenance, and this is another sore spot for some who don’t mind spending time under the hood, especially when they notice little performance benefit.
The main purpose of installing it is to protect the turbocharger and to date it has not been shown to increase power. However, on some car models, an immediate shift in the car can be felt, particularly when changing gears, due to the continuous spinning of the turbo under tight throttle conditions, allowing for a faster “full boost” for the car .
