Running a 44mm wastegate on my setup, I have been told that if I am running a Manual Boost Controller, that the MBC won't be able to change the boost if I am running anything over what the wastegate spring is at?

Reason being, I want a 10 psi spring, no wastegate when I'm just cruising around at 6 psi, and then turn the boost up to 15+ when I'm racing. I want to be able to turn the boost up, and I've been told I can't. Is this true?

Also, what is the advantage of a larger psi wastegate spring? No one I know seems to be able to explain this to me.

Thanks!

 

You can increase boost over what the wastegate is rated at but cannot reduce it.

So if you have a 10 PSI spring you will run 10 PSI with no MBC. With a MBC you can easily turn it up to 15 PSI. However, you cannot turn it down to 6 PSI.

A MBC can only increase boost about 50% over the spring rating safely, so you want a larger spring if you are going to run more boost.

 

im running a 9psi spring and boosting 20psi+ witha mbc no problem here