Spool up

[kuzman83]

dumb question here but does having a g valve versus a custom cal affect the quickness of the turbo spool? like is one faster than the other?

[iTurbo]

A grainger valve will always provide the fastest possible boost response because of the way the valve works. It prevents the wastegate from opening at all until a preset pressure is reached, dictated by the spring pressure. Once enough pressure is reached, the ball inside becomes unseated and allows pressure to act upon the wastegate. In other words, the wastegate remains closed until you are at your boost goal.

[Anonymous_User]

A grainger will reduce spool from a stock cal.

A good aftermarket cal will operate the wastegate the same as a Grainger. I know that Blueberry and Ladybug provide the same spool time as a grainger from personal experience.

[kuzman83]

anyone got a tech article on how to set up a grainger valve?

[kuzman83]

i just read a tech article on the dempsey bowling site and i understand it all except the restrictor. what the hell is it and how do i get one, which one should i get (flow/size)

[MiniMopar]

The size is not that important for the most part. I know the "Vacutite" selection at some auto parts stores will sell them in some random size. That size will work. It's just a vacuum coupler with a brass insert that has a small hole in it. It's job in this case is to vent the pressure in the actuator can so that the wastegate can close again when you lift. Gus explains it further:

http://www.gusmahon.org/html/boostcontrol.htm

[MiniMopar]

...as to the spoolup versus a cal, any cal can be made to behave like the G-valve, but the stock cal does not for driveability and probably durability concerns.