Raz, thanks for posting. It gives me something to check out tonight so I do not have to sit inside while the old ball and chain watches her fucking HGTV. Seriously, appreciate the tip. M.

 

I'm glad this topic has come up as I need to look more closely at it too. I get a lil bit of a pressurized burp from the exhaust, almost like a backfire without the bang, even when letting off of part throttle on occasion. It doesn't do it often but it seems like air/blower cough bucking through there. Not sure if this is the reason, but hopefully. I bought that set positioner thing from Lingenfelter when I was putting it back on after the smaller upper pulley install and all seemed OK, but that was my first time doing it so WHOOOOOOOOOO knows.

 

I noticed on mine I could actually push the bracket towards the S/C far enough that it would make contact with the plate even though the adjustment screw was completly out. So I moved it away from the S/C to where the adjustment screw had one full thread about to touch the plate much like you did Raz.

So Raz, after you installed the new bypass it doesnt "click" at the mid point when actuating manually?

 

Yep. It's smooth all the way through the full motion. Before sometimes half way it would stick and than pop.

 

Is there a way to just disconnect the boost bypass? In the Ford community we have just unplugged the electronics to it - problem solved and no lost boost at any point. The CTS-V has perplexed me as to how to just get rid of the boost bypass.

 

Good info, thanks

 

What would the symptoms of this be? I just checked mine and based on the marks from the original bolts it seems to be off. Its not making contact with the set screw

 

I'm confused a little. Could y'all explain the purpose of the boost bypass?

I was messing around with mine a little tonight trying to set the mount in the right place. So I need to mount the bracket like Razor did and then unscrew the set screw a little?

 

There is a set tool D. It opens the blade in the snout to let air bypass the blower and let air run around it so the air isn't backing up and the blower creating unneeded heat.

 

Ok. That's what I thought. Just needed to hear it from a pro!

 

Just want to make sure I have it clear. After moving the bracket as far forward as possible toward the engine, you want the set screw to barely make contact with the plate. Right? Cecil............

 

I believe that is correct Cecil. Hopefully Ben or Razor will chime in.

 

Since it's Christmas, they are probably with family. Maybe tomorrow if they don't check in. I went ahead and set it so that the
set screw just pushes against the plate slightly. Thanks for your response, gives me confidence that I'm reading it correctly. Cecil..............

 

No problem. I need to realign my mount and set the screw. I just moved and I couldn't find my allen wrenches.

 

Before adjusting the bypass actuator and arresting screw, it would be wise to understand the design intent and ramifications of incorrect adjustment.

1. On our CTS-V's the bypass actuator is primarily used for unloading the supercharger when boost is not required. I.e., when the engine has vacuum the actuator pulls the plate open so some air can bypass the rotors and feed the engine unhindered (as per Ben's posts).
   • Disconnecting a correctly operating bypass will not assist the engine to create more power (despite what some Ford forums may claim). In fact, it will usually cause an increase in IAT's & will certainly shorten the life of many components.
2. On the LS9 & LSA platform, the bypass actuator is also used for "bleeding" boost during some of the torque management strategies. If tweaking these strategies is desired, it should be done via tuning the software parameters - not via any mechanical means.
3. An incorrectly adjusted bypass system can cause the bypass throttle-plate to not seat (leak); jam/stick shut (not bypass immediately); pull over-centre & jam/stick open (always bypass); self-destruct (cause the diaphram to tear).

The correct adjustment of the bypass is to have 2.0-2.5mm of preload after the throttle plate is arrested. Therefore, the order of adjustments makes a difference.
I recommend:

1. Back off the arresting/adjustment screw so the lever is well clear.
2. Loosen (not remove) the actuator fasteners & pull the actuator forward (away from the shaft).
3. Gently slide the actuator towards the shaft/lever until the shaft/lever stops moving, indicating the throttle-plate is seated.
4. Push the actuator another 2.0-2.5mm to "preload" the plate.
   • Too much preload may lead to the plate sticking after some time as the arrestor wears, & may also sacrifice full movement.
5. Tighten the fasteners, taking note not to allow the actuator to move.
6. Adjust the arresting/adjustment screw until it touches the lever, plus 1/4 to 3/4 of one turn.
   • Ideally, less clearance is better but too little and it will stick during thermal changes. Too much, & boost will bleed.
7. Manually rotate the lever to ensure the movement is smooth and unhindered during the action.
   • Do not pull on the actuator shaft itself as it is easy to tear the diaphram by moving it off the centreline.
8. Start the engine and note the movement, ensuring there is no "stiction".

Other items to check for include:

• A small amount of lubricant/grease on the lever/actuator interface.
• All hoses, tubes, elbows are fully engaged and not perished.
• The action of the lever is not interferred with from foreign articles (cable ties, NO2 plumbing, wires etc).

Hope this helps.

 

So are you saying that Razor's post is incorrect?

 

Not necessarily, as what Razor has done on his supercharger may achieve the desired result on that vehicle.
However, the stack up of manufacturing tolerances is why the actuator is slotted and why there is an adjustment available.
What I am saying is that every supercharger is slightly unique and the process above will render the actuator positioning functionally correct.

 

This might get interesting. Several of the people, includeing myself, have bypassed the P-Valve because we have upped the boost and I was under the impression
that the P-Valve would bleed off any extra boost. I have disconnected my X line and P line, so I don't think the valve is bleeding anything off of mine. There was a
long discussion about this some time ago at another CTS-V site. Now you have me worried. Its been this way for about a year. Cecil............

 

Disconnecting the pressure line will not cause problems, unlike disconnecting the vacuum line ... however a better method is doing it via the tune file.

 

Which one is the vacuum line? Is it X,O, P ? What time is down under if its 12noon here? Cecil.............

 

Haha I feel the same way Cecil!

 

There are 2 ports on the actuator.
The port furtherest from the bypass shaft (towards the front of a CTSV) is the vacuum; the port closest to the shaft (rearward in a CTSV) is the pressure.

BTW ...
12 noon PST = 7am in Melbourne (until daylight saving changes again).

 

There are 2 ports on the actuator.
The port furtherest from the bypass shaft (towards the front of a CTSV) is the vacuum; the port closest to the shaft (rearward in a CTSV) is the pressure.
View attachment 4712

BTW ...
12 noon PST = 7am in Melbourne (until daylight saving changes again).

Finally a simple image with explanation!

 

This might help in addition to what was previously listed. As a side note, verify from your tuner what parameters they have set the relief at. Our OEM specs are, if I recall set to 12psi? The tuner I have used changed them to 17psi, so that the mod to this boost control module would not be necessary...
Hope this helps

 

I used the alignment tool when I set it up and it was alligned perfectly. I just took a picture of it to visually show a quicker way of making sure yours is setup correctly. It should be fine from the factory but i'm guessing 80% of shops that mod and touch that bypass wont put it back the way it should be. When the bracket is shifted back like in the first picture it actually pulls the actuator rod in a position that is not stationary at rest but in constant tension. The point where the second picture shows is the moment the rod is in a rest position. My car boosts pefectly fine and like cecil said. Disable it in the tune. If you bypass the whole deal and chuck it you'll get much faster boost since you'll be running off the blower but your iat2's will be considerably higher and you're straining the blower/wearing parts unnecessarily. It would be nice to see stock untouched bypass pictures for a comparisin in bracket location.

 

I should have taken a picture of mine. Mine is stock but it wasn't mounted flush against the edge like your second picture.

 

interesting to know, It would be great to see even two stock pictures and see how accurate they are from the factory in terms of placement mounting

 

maybe i asked the wrong question just noob and dunno where to start. i have read the thread if that helps lol!

 

i hooked that back up

seems like boost comes in slower and doesnt go up as high

i followed performance defined allignment steps.

of course im assuming that it needs the tune compensated, not that anything is necessarily wrong.

it does seem like the mileage is coming up tho!

 

Yep. Thats exactly what it supposed to do. I've heard someone say it did lower their et by about .2 . But like I said, you're running off the blower. You'll need much less throttle to get into boost and when it does go into boost you'll hit more faster. At the expense of iats and throttle control. ( and prob reliability ) I think though when some shops do it it also gives the owner a more of a "holy shit" its fast now expeirance. Pd, might be able to better clarify the exact results of running the boost hard like that long term. I would guess more rotor wear from the higher iats.

 

Everything within the supercharger will benefit - the oil, gears, seals, bearings etc.
Additionally, the belt & tensioner will last longer & the engine will be less stressed during cruising.
The modulation of the actuator and the boost pressures can be tweaked in the tune - the same "power feeling" result as disconnection without the down-side.