What is: Boost Valve Mod?

n0dih · #1 (**permalink**) 06-05-2008, 01:49 PM

Saw some references to it, but what is it?

dayday · #2 (**permalink**) 06-05-2008, 02:02 PM

"Copied from ZZP's website"

Tools Needed:

1 - 3/8 Drive Ratchet
1 - 3/8 Drive Small Extension
1 - 3/8 Drive 10mm Universal Socket

Instructions:
Step 1: Locate hood release in driver side foot well.

Step 2: Pull hood release toward you to pop the hood open.

Step 3: Open hood by placing your hand between the hood and front bumper cover, making a left to right motion, catching the hood latch.

Step 4: Raise hood.

Step 5: Locate the Supercharger Boost Bypass Valve. It is the black cylindrical object on the right of the supercharger, above the front valve cover.

Step 6: Move the large set of wires aside from in front of the valve cover. They are held in place by a metal clip that is easily undone.

Step 7: Find the first 10mm nut, located just in front of the Bypass Valve, and loosen nut. DO NOT REMOVE!

Step 8: Find the other two 10mm nuts; they are located BEHIND the Bypass Valve, on the supercharger housing.

Step 9: Loosen these two 10mm nuts. DO NOT REMOVE! The first nut can be accessed from the left side of the Bypass Valve, the other one is a little trickier, and can be accessed from the right side.

Step 10: Once all three nuts are loosened, gently apply pressure in a downward motion to the Bypass Valve. You will notice it may move as much as one-half inch.

Step 11: While pushing down on the Bypass Valve, retighten the three nuts, in the order you loosened them. First the right side, then the left, and then the front.

Step 12: Re-clip the large set of wires back into the metal clip.

Step 13: Close hood.

Thanks to Luan Zeqollari for this info.

This modification won't help everyone. It does help you for gaining hood clearance after adding an intercooler. It also helps some cars achieve full boost that were having problems with the bypass not closing all the way during WOT.

n0dih · #3 (**permalink**) 06-05-2008, 02:19 PM

So pretty much that mine rests on the stop engine off means it is fine and I don't need to worry about it?

I have seen as high as 158 kPA on my datalog. Stock everything except tune.

Thanks for finding it, I did some google searches and came up dry.

dayday · #4 (**permalink**) 06-05-2008, 03:37 PM

Quote:

Originally Posted by n0dih

So pretty much that mine rests on the stop engine off means it is fine and I don't need to worry about it?

Not necessarily, the plunger inside the valve is what will move if you loosen and push down on the valve. Pretty sure when you see the arm resting on the stop with the engine off your seeing the valve in it's open position, this mod helps ensure the valve is closing all the way under boost.

wagoner2 · #5 (**permalink**) 06-05-2008, 03:43 PM

Is there any reason not to do this?

1Hot97 · #6 (**permalink**) 06-05-2008, 03:57 PM

Yes, It could result in your car making full boost sooner, or making boost under fairly light throttle, which could result in poorer MPG,

wagoner2 · #7 (**permalink**) 06-05-2008, 04:38 PM

Quote:

Originally Posted by 1Hot97

Yes, It could result in your car making full boost sooner, or making boost under fairly light throttle, which could result in poorer MPG,

Is that the only down side? If you aren't worried about MPG's is there any other negatives?

dayday · #8 (**permalink**) 06-05-2008, 05:09 PM

Quote:

Originally Posted by wagoner2

Is that the only down side? If you aren't worried about MPG's is there any other negatives?

Pretty much what 1hot97 said. You "may" get into boost sooner resulting in less MPG and also it may make the car a little harder to launch at the track.

I think the issue that brought this mod about was the fact that Eaton was not very accurate when adjusting the BBV on the blowers. Some see a difference with the mod, other people who's were set better from the factory will see less or no change.

wagoner2 · #9 (**permalink**) 06-05-2008, 05:43 PM

Quote:

Originally Posted by dayday

Pretty much what 1hot97 said. You "may" get into boost sooner resulting in less MPG and also it may make the car a little harder to launch at the track.

I think the issue that brought this mod about was the fact that Eaton was not very accurate when adjusting the BBV on the blowers. Some see a difference with the mod, other people who's were set better from the factory will see less or no change.

Lord knows I don't need to do anything to make my launches worse!