Originally Posted by Mileguru (Post 5460075)

I'm interested to see if anyone else has a Magnuson TVS1900 on a 2014+ 6.2L and what boost they are getting.

I'm getting frustrated with my setup (referenced above, only I have a 2017). With everything stock except the supercharger and catch can, the 84mm pulley that came with the kit only produced 4psi (when it was supposed to make 6psi). I showed Magnuson the data log and they immediately sent a 78mm pulley and a new tune, which then made 5.8psi. So why does Magnuson include the 84mm pulley with the kit if it only makes 4psi? And the 84mm is still what you get if you order a kit right now, I checked, so it wasn't a mistake. Is it possible that my truck is just weird or something went wrong with the install, and that's why I was 33% short in boost? My elevation is only 730 feet, too.

Originally Posted by smokinlmm (Post 5460086)

You need to check to see if your bypass valve is closing all the way. It will bleed off boost if there is a tiny gap when it is fully closed. Mine wasn't sealing either, I fixed it by adjusting the actuator and I also made shorter vacuum lines and zip tied them all so there aren't any leaks. You have to remember your boost only comes on if your evap and boost actuator systems are functioning properly also. There are test for each, I recommend you start researching them...

Originally Posted by 03sierraslt (Post 5460094)

What does evap have to do with it making boost?

Originally Posted by Mileguru (Post 5460123)

The set screw and plate are making full contact while off and at idle. Is there another way to examine the actuator/bypass valve?

Originally Posted by smokinlmm (Post 5460124)

i

Vaccum pressure actuates the boost valve, if you have a leak it won't pull the valve all the closed. Also make sure nothing is in the way of the actuators range of motion....

Originally Posted by MikeGyver (Post 5460128)

It works backwards to my old Whipple bypass? Mine opens with loss of vacuum. It's closed with the engine off, and fully open at idle (bypassing) because there's vacuum. If they are opposite, sorry to add any confusion.

Originally Posted by MikeGyver (Post 5460166)

My point was not about that, but that everybody is talking about vacuum, and you are asking why you don't have enough boost. You don't need vacuum at the bypass to make boost.

Maybe your math is off? How are you measuring boost?