Pulley size and boost levels
Mar 31, 2019 | 08:46 AM
#101
TECH Addict
Joined: Nov 2015
Posts: 2,125
Likes: 573
From: Coastal NC
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.
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.
Mar 31, 2019 | 11:07 PM
#103
Staging Lane
Joined: Oct 2017
Posts: 82
Likes: 12
From: Southern CA
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...
Apr 1, 2019 | 04:51 AM
#104
TECH Addict
Joined: Nov 2015
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From: Coastal NC
Apr 1, 2019 | 05:21 AM
#105
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Joined: Nov 2015
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From: Coastal NC
Apr 1, 2019 | 06:08 AM
#106
Even with a small vacuum leak, the engine should draw more than enough vacuum to close the valve
Apr 1, 2019 | 07:54 AM
#107
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.
Apr 1, 2019 | 05:31 PM
#108
Staging Lane
Joined: Oct 2017
Posts: 82
Likes: 12
From: Southern CA
My fault. I meant the set screw and plate are making full contact while off and FULLY OPEN while at idle.
Apr 1, 2019 | 08:12 PM
#109
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?
Maybe your math is off? How are you measuring boost?
Apr 1, 2019 | 08:46 PM
#110
you are right, I was think of something else. The valve should be normally closed. Either way it shouldn’t be effected my a evap leak