Does anyone here have any input on this? The actuator bracket is slotted and you CAN make adjustments on it. At idle it is wide open right? So when you take away vacuum it closes completely right? If anybody can enlighten me on this I would appreciate it. I have got some conflicting advice so far. I for one can't see how adjusting this would do any good unless the boost bypass actuator is running partly open and that should not be because with a lack a vacuum it stays closed...

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99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net

 

http://nloc.org/ubb/Forum2/HTML/000645.html

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Red '00 Lightning,
Power Surge Performance enhanced,
375 RWHP,
445 RWTQ,
12.974@104.818
Track Videos

 

So when the lever is all the way down against the stop the actuator is closed? Meaning no bypassed boost? Thanks

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99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net

 

It is opposite of what you say. When running with vacuum (normal cruising) the rod is pulled all the way up away from the stop. As vacuum drops the rod is released opening the flap to allow boost to enter. If you raise the accuator it will deliver boost sooner. If you raise it too much though you will not have vacuum even at cruising speed. I raised mine about an 1/8 in and got about an extra lb of boost.

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2001 silver Lightning
'69 Mustang GT
'82 Mustang GT (drag)
'48 Ford F1 pkup

 

So the butterfly that is attached to that arm allows more boost? I thought it only dumped boost. So under full throttle the arm is down and the butterfly open to increase boost? So when you hit the rev-limiter and boost is dumped how is that achieved? I thought the butterfly that is inside the lower part of the blower had to be open to bypass boost not closed..

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99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net

[This message has been edited by JeffsLightning (edited 05-20-2001).]

 

Jeffslightning
I think you have the workins of that thing figured out OK. When the engine is at idol and at full vacuum then the arm is pulled up toward the hood. That is at full bypass and the valve is wide open. (I have a spare blower and have verified all of this on the bench). When you step on the throttle the vacuum drops and so does the arm, this closes the valve and stops bypass. When the valve is closed and there is no more bypass then and only then will the blower begin to make boost. If you start up your truck and get under the hood and work the throttle by hand you can watch all of this happen.

So I have the same question that you do. How in the hell can you "raise" the spring loaded canister and take spring tension "OFF" of the arm and have it get you more boost and better boost response. That seems completely backwords to me.

I think you would have to increase spring pressure ( lower the canister ) to work harder against the vacuum source, so it would snap the valve shut quicker.

If anybody could splain to me were my thinkin is wrong, I would appreciate it.

Anyway it doesn't matter because that is a simple adjustment and I will form my own conclusion when I run out of other stuff to mess with.
Dale

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Black 00'
12.977 @ 110.49
full weight, stock F1's

[This message has been edited by Bad as L (edited 05-20-2001).]

 

Here is how you keep from loosing the boost.

If you look close you will see that the pink hose is removed from the top vacuum port. and a screw is put in it's place.

The pink hose is then attached to the vacuum lines with a T

here is a pic of the mod.


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DON'S ZR1 KILLER
SILVER 2001 LIGHTNING
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JDM BigMouth Filter.
13.248 @ 104.61
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Dale and I are thinking alike on this. We can't understand how you can increase boost by raising the diaphram towards the hood. This would open the bypass butterfly more.
Don I can't make out what you are talking about in regards to the actuator. Did you just unplug the vacuum line fron the boost actuator and plug it with a screw? This would keep the boost bypass butterfly closed irregardless of vacuum. My whole question with this is that I don't think you can raise boost with this butterfy unless for some reason it is staying open when the actuator does drop(towards engine) the arm onto the stop when vacuum is lost. Thanks for the input guys... Jeff

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99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net

 

Dale since you have a spare blower can you tell me if that stop screw that the boost bypass actuator arm rests on has some sort of adjustment on the bottom(towards engine) of it. I can feel with my finger that there is an acess hole under there but I have know way of seeing if it's slotted or allened or what. If that screw stop could be screwed in more then the arm would close farther therfor ensuring that the boost butterfly is completely closed. thanks



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99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net

 

Jeff
to answer your question
"Did you just unplug the vacuum line from the boost actuator and plug it with a screw? This would keep the boost bypass butterfly closed irregardless of vacuum."

Yes thats what I did, and yes it keeps the butterfly closed all the time. I had my truck data logged so I know my max boost is 10 lbs, so I should be fine.

Moving the accuator will not give you any more boost than you have now. It will just bring the boost on alittle sooner.

What you want to do is adjust the lever so it just barely touches the stop.

 

Again, boost is bypassed with the rod in the up position. Watch it at idle. The rod is pulled all the way up. No boost, full vacuum. Watch as you snap the throttle suddenly. The rod drops as vacuum decreases. Once vacuum is at zero you will then be into boost. That is why it must be raised. It will build boost sooner and build quicker. Result could be more boost, but again don't go to far because the drag of the truck for example cruising at 80mph will cause loss of vacuum and boost actuation too easily. Also in a towing situation you might find that vacuum drops too easily. This is how I understand it anyway and it works for me.

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2001 silver Lightning
'69 Mustang GT
'82 Mustang GT (drag)
'48 Ford F1 pkup

 

Jeffslightning
Went and checked the blower case. The adjuster screw is socket head (Allen). A 4mm fits perfect and a 5/32 fits alittle loose but will work fine. I tried turning the adjuster screw and it wasn't to hard at all.

On both my stock and new blower the bypass valves seem to be adjusted just fine. But that doesn't mean everybody's are.
Dale

 

Also, that is why when Don removes vacuum from the actuator, it is disabled (the rod will be fully out and no bypass).
But in my opinion, I find that vacuum drops too quickly when the vacuum source is disconnected and plugged. It's great for racing (you know you will not lose boost and maximum boost will be achieved).
But not the best for normal driving, towing, or gas mileage. Again I am not disputing what you say Don. I know what you're saying works too.
Uhhh maybe I have it all wrong. JL, Sal, Jim??


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2001 silver Lightning
'69 Mustang GT
'82 Mustang GT (drag)
'48 Ford F1 pkup

 

Snakepit
Hey no problem,you may be right, Hey I am no rocket scientist, and by the way it was Jim D who did the vacuum mod on my truck. From what I understand all this mod does is get rid of bipass if you over rev the engine.

As far as normal driving I don't notice a differance. Also since he tuned my truck my millage has gone up allmost 2 mpg.

 

So I will be ok if I plug the boost bypass actuator also? Also can you tell me some more about JDM's tuning on your 01? I'm either going with a lower puley or a chip soon but for now I'm leaning towards the lower pulley. I think some more R&D needs to me done on the 01's....maybe his though. Thanks

Jeff


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99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net