not really, but recommended, you want to give your turbo time to cool down, if your a person whos willing to sit there for a few minutes and let the car idle, then you dont need one, otherwise its something that keeps the engine running for a set amount of time based on how hard youve run the car, and is suppose to prevent the car being taken without the key, etc yada yada so, let your car idle a while every time and save some money ^_^

 

They are cool though. I installed one in my car just a while ago and whenever I go to park my car and get out, lock it, and walk away with the keys in my hand, everyone looks at me like "dude, your car is still on." Just another way to turn heads I suppose while making sure your cooling that turbo down.

 

Thats pretty cool.... do most turbo apps. have boost controllers or are they self checked?

 

The purpose of a boost controller is to increase boost from the base external wastegate spring.
IE: lets say you have a 7 psi spring in your wastegate, the boost controller will give you the ability to increase that 7 psi to that max capable for the turbo. Good if you have everything need to do that properly, bad if you dont have your engine build up and dont have high octane gas ^_-
If you want a set psi that doesnt change, you dont need a boost controller, if you want to be able to change it, then get something like a 1 psi spring and setup your boost controller so you will offically have some gas economy when your running at higher rpms.

A boost controller will not lower the boost below the naturally spring of the wastegate if you have 7psi and want less, the only way to lower it is to replace the spring.