EDIT: Please read through to the end of the thread, I did this mod 3 different ways. The final way version 1.3 was the cleanest looking under the hood.
While doing research through the forums about the boost bypass actuator I discovered some things that are important for terminator owners. It has been debated over and over about the boost bypass modification that prevents the boost bypass actuator from bleeding off extra air when not in boost. I actually drove around with the modification done for 4 years thinking the whole time that it was not causing any performance issues.
I recently found out through reading through threads about this, that disabling the boost bypass actuator actually causes the blower to build up to much heat when not in boost. Apparently when not in boost the Eaton blower, especially with a pulley, moves more air than the engine can take at low throttle rpm. The result is air turbulence called cavitation which causes friction and heat.
So last week I switched the two vacume lines back so that the actuator was functional again. The result was that the air intake temps dropped about 20 degrees when just driving around not in boost. However, with the canned predator tune I have, the boost bypass solenoid solenoid still caused the boost bypass actuator to bleed off boost at wide open throttle. The car did not pull as good as it did before I reversed the boost bypass mod. I wanted the boost back, but I did not want the high intake temps that go along with disabling the actuator.
I kept on reading old threads and came across a post by RWTD the tuner. He mentioned a rerouting of the vacume lines that he does that prevents boost bleed off at wide open throttle, while at the same time enabling the boost bypass actuator to continue to function while not in boost. Here is how to do this mod.
First remove the two vacume lines that attach to the top and bottom of the boost bypass actuator. Then remove the two vacume fittings from the ends of the hard plastic lines and replace them with the correct size caps.
The two vacume fittings that are removed
The two vacume line caps that replace them
Pic of the two lines after they caps have been installed
All that is left to do now is remove the vacuum line from the FRPS sensor at the end of the fuel rail. After this you install a Y vacume fitting between the FRPS and the vacuum line that was attached directly to it.
Now you just attach a 10-11 inch section of vacuum line from the Y fitting and run it over to the top fitting on the actuator.
The lower fitting on the boost bypass actuator remains vented to atmosphere.
Now the boost bypass actuator works as designed and is no longer effected by the boost bypass solenoid and the computer never knows the difference. Another way to accomplish the same thing is to unplug the boost bypass solenoid. However, this causes the computer to throw a soft code.
While doing research through the forums about the boost bypass actuator I discovered some things that are important for terminator owners. It has been debated over and over about the boost bypass modification that prevents the boost bypass actuator from bleeding off extra air when not in boost. I actually drove around with the modification done for 4 years thinking the whole time that it was not causing any performance issues.
I recently found out through reading through threads about this, that disabling the boost bypass actuator actually causes the blower to build up to much heat when not in boost. Apparently when not in boost the Eaton blower, especially with a pulley, moves more air than the engine can take at low throttle rpm. The result is air turbulence called cavitation which causes friction and heat.
So last week I switched the two vacume lines back so that the actuator was functional again. The result was that the air intake temps dropped about 20 degrees when just driving around not in boost. However, with the canned predator tune I have, the boost bypass solenoid solenoid still caused the boost bypass actuator to bleed off boost at wide open throttle. The car did not pull as good as it did before I reversed the boost bypass mod. I wanted the boost back, but I did not want the high intake temps that go along with disabling the actuator.
I kept on reading old threads and came across a post by RWTD the tuner. He mentioned a rerouting of the vacume lines that he does that prevents boost bleed off at wide open throttle, while at the same time enabling the boost bypass actuator to continue to function while not in boost. Here is how to do this mod.
First remove the two vacume lines that attach to the top and bottom of the boost bypass actuator. Then remove the two vacume fittings from the ends of the hard plastic lines and replace them with the correct size caps.
The two vacume fittings that are removed
The two vacume line caps that replace them
Pic of the two lines after they caps have been installed
All that is left to do now is remove the vacuum line from the FRPS sensor at the end of the fuel rail. After this you install a Y vacume fitting between the FRPS and the vacuum line that was attached directly to it.
Now you just attach a 10-11 inch section of vacuum line from the Y fitting and run it over to the top fitting on the actuator.
The lower fitting on the boost bypass actuator remains vented to atmosphere.
Now the boost bypass actuator works as designed and is no longer effected by the boost bypass solenoid and the computer never knows the difference. Another way to accomplish the same thing is to unplug the boost bypass solenoid. However, this causes the computer to throw a soft code.
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