Unplugging Boost Bypass
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Unplugging Boost Bypass
I am about to leave work and I want to unplug the boost bypass. I know where it is located but do I have do anything before hand like disconnect the battery? Thanks in advance
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From: Mid West
I wrote this for Doug. This should help.
The Lightning motor has a valve on the near the back of the blower on the drivers side that relieves or bypasses air past the blower. This valve serves two purposes on the Lightning motor. During high vacuum situations (when you are not requiring high power), air leaks around the blower to avoid ware on the blower drive and heat. Once the motor gets to 0 vacuum on it's way to boost, the valve is designed to close and allow the motor to build boost. The other function that this valve is designed to do is protect the motor from over-boost when the motor hits the rev limiter. The problem is that when this boost bypass is energized, it remains in that position for quite some period of time. This only seems to happen when doing tire warming at the track and the first time you find out that the bypass is in 0 boost mode is about 30 ft from the start line on your way to a 17sec @ 78 MPH pass. This mod is the 10 min and $3 solution to this problem. Note: I have heard that the boost bypass my come in with an over-heat situation and may also come in with the torque reduction if still active in your chip.
Remove the pink line from the top of the boost control diaphragm valve, (not the solenoid valve) and plug it. I used a 1/4" bolt cut to about 3/4 inch long but that still has about 1/4" of smooth shank so you don't get an air leak. You can use a 1/4" hose mender and a 1/4" cap.
Next, get 3/16" Tee at the auto parts store. Put this Tee into the boost hose that goes into the firewall and up to the boost gauge(there is a white 3/16" hose mender in this location stock). Get 9" of 3/16" rubber fuel line to go from this Tee to the top of the boost control valve.
The result is the computer will no longer have the ability to dump boost at the shift (torque reduction) or as part of the over-rev protection. The computer will never know and will not throw a soft or hard code. The boost bypass will still be active at idle through near zero vacuum, and closed shut in all boost conditions. Just be careful, The computer can't help protect you from over-revving and over-boosting or over-heating and doing
damage to the motor.
see http://www.ncs-stl.com/Images/BoostMod.jpg for photos
Andy
The Lightning motor has a valve on the near the back of the blower on the drivers side that relieves or bypasses air past the blower. This valve serves two purposes on the Lightning motor. During high vacuum situations (when you are not requiring high power), air leaks around the blower to avoid ware on the blower drive and heat. Once the motor gets to 0 vacuum on it's way to boost, the valve is designed to close and allow the motor to build boost. The other function that this valve is designed to do is protect the motor from over-boost when the motor hits the rev limiter. The problem is that when this boost bypass is energized, it remains in that position for quite some period of time. This only seems to happen when doing tire warming at the track and the first time you find out that the bypass is in 0 boost mode is about 30 ft from the start line on your way to a 17sec @ 78 MPH pass. This mod is the 10 min and $3 solution to this problem. Note: I have heard that the boost bypass my come in with an over-heat situation and may also come in with the torque reduction if still active in your chip.
Remove the pink line from the top of the boost control diaphragm valve, (not the solenoid valve) and plug it. I used a 1/4" bolt cut to about 3/4 inch long but that still has about 1/4" of smooth shank so you don't get an air leak. You can use a 1/4" hose mender and a 1/4" cap.
Next, get 3/16" Tee at the auto parts store. Put this Tee into the boost hose that goes into the firewall and up to the boost gauge(there is a white 3/16" hose mender in this location stock). Get 9" of 3/16" rubber fuel line to go from this Tee to the top of the boost control valve.
The result is the computer will no longer have the ability to dump boost at the shift (torque reduction) or as part of the over-rev protection. The computer will never know and will not throw a soft or hard code. The boost bypass will still be active at idle through near zero vacuum, and closed shut in all boost conditions. Just be careful, The computer can't help protect you from over-revving and over-boosting or over-heating and doing
damage to the motor.
see http://www.ncs-stl.com/Images/BoostMod.jpg for photos
Andy
Last edited by awhittle; Apr 6, 2002 at 10:56 AM.
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From: Southern ILL.
Boost bypass
I'm kinda new to the whole boost world if you have no over-rev over boost, or thermo protection what are the chances of this happening.
If the L is kept in drive won't it shift before the over-rev protection is needed?
Will this keep the truck from falling on it's face when it shifts into 2nd. and if so is it gonna be hard on the tranny?
Will a chip protect from the over rev, boost, thermo, condition.
Thanks alot
If the L is kept in drive won't it shift before the over-rev protection is needed?
Will this keep the truck from falling on it's face when it shifts into 2nd. and if so is it gonna be hard on the tranny?
Will a chip protect from the over rev, boost, thermo, condition.
Thanks alot
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So I unplugged it and I figure I threw a code because I now have service engine light. I havent plugged it back in yet but when I do will the light go away or is the code going to have to be cleared. Thanks for the details Awhittle!
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From: Mid West
RhinoSlug
Take the neg wire off the battery. Turn on the lights for about 30 min. Hook up the boost control valve. Turn off the lights. Hook the battery back up. That should fix the code. The truck may run a little strange untill the computer is retought. I bet in the 30 min you can do the boost mod.
Andy
Take the neg wire off the battery. Turn on the lights for about 30 min. Hook up the boost control valve. Turn off the lights. Hook the battery back up. That should fix the code. The truck may run a little strange untill the computer is retought. I bet in the 30 min you can do the boost mod.
Andy
