Synapse Wastegate vacuum diagram

[Mobius]

Originally Posted by RotaryProphet

No, you don't need a boost controller unless you want to change the boost level from the cab. Just hook up the ports according to which boost level you would like, and to change the level, move the hoses.

^^ What he said, or unless you want a higher boost level than what is available (the highest I can go without a boost controller is 17psi.)

Also note that the boost level they claim may not be what you actually get, it takes a little trial and error sometimes, with different spring/port combinations. I think they have a disclaimer stating this as well.