Some inside info on the bypass solenoid
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Some inside info on the bypass solenoid
I have a good friend from my LS1 travels that used to be an electrical engineer at GM and was one of the designers on the LSJ project. He was involved in the tuning aspects of the build and now works for a high profile tuning business.
Anyhow, he saw I was playing around with the SC Cobalt, and he gave me the following info regarding the electric solenoid connected to the boost bypass actuator:
Hope this is not repeat info! I searched but it seemed no one knew this.
Anyhow, he saw I was playing around with the SC Cobalt, and he gave me the following info regarding the electric solenoid connected to the boost bypass actuator:
There's a electric solenoid with a couple vacuum lines on it that run to bypass valve. It's there to apply pressure to the bypass valve and OPEN it in the upper RPM to make the power drop off for shift feel. The power never nosed over in production so the chief engineer could never shift the thing correctly so, i had to implement boost control in the PCM on a supercharger. DUMB! Leave all the vacuum lines attached, but just unplug the 2 wire connector from that solenoid. It will not affect the PCM.
welcome to 3 years ago. if you search for "boost bypass mod" you will find info. the solonoid is there to actuate the bypass valve, something eaton has been using since the late 80s. its there to open up in overboost conditions, limit boost in lower gears (the cobalts run the solonoid at 50% duty cycle in 1st gear), and can be used for failsafe conditions. with the stage 2 reflash it limits boost a bit in 1st gear however it doesnrt dump the boost at higher rpm.
im sure unplugging the solonoid will set a code along the lines of "boost solonoid open or short"
im sure unplugging the solonoid will set a code along the lines of "boost solonoid open or short"
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Cool....I did a search and the only threads I found wre folks talking about the switch and that they were not sure what it did, etc. I thought someone had to have known this since these cars have been out for a while.
Lewis...I'd say mid 30s.....name is Matt Harlan....hangs around with the Stenod Performance gang all the time. Used to have an 8-second TT Trans Am with a factory PCM.
Lewis...I'd say mid 30s.....name is Matt Harlan....hangs around with the Stenod Performance gang all the time. Used to have an 8-second TT Trans Am with a factory PCM.
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