Cams and brake booster vacuum...

[376LS3]

Open the butterfly with the actuator with your hand while the car is running and see if your vacuum goes up. I remember when I turbo'd my RX8, The biggest thing to look for was a sudden loss in vacuum. That meant you popped an apex seal. (Equivalent to piston ring) Maybe you have too much ring gap???

[lexlueger]

Originally Posted by PQ

We'll see. I can't mess with it till Saturday now.

I did change them. Also sprayed mucho propane gas in that area when testing for leak. BUT I'm going to go at it with some carb cleaner next.

I'm a little surprised that nobody thinks that the overdrive pulley spinning the blower faster than standard could be the deal.

19 psi here, blower speed is not your issue.

[PQ]

Originally Posted by 376LS3

Open the butterfly with the actuator with your hand while the car is running and see if your vacuum goes up. I remember when I turbo'd my RX8, The biggest thing to look for was a sudden loss in vacuum. That meant you popped an apex seal. (Equivalent to piston ring) Maybe you have too much ring gap???

I'll try it.

Originally Posted by lexlueger

19 psi here, blower speed is not your issue.

I was just curious because when I had the 1:1 pulley set i could push the gas and as the rpms went up the blower turned faster (obviously not into boost) and the vacuum went down like normal. Of course when it hit boost it would be PSI.

So if the vacuum decreases by spinning the blower a little faster with a 1:1 in back it would make sense that putting an overdrive set where it was, say, 1.5:1 then the vacuum would decrease.

Anyone who get's in their car with a boost gauge can lightly push on the gas and watch the vacuum go down.

So if it's N/A it happens with only the natural piston flow. But with the blower, IF it were actually trying to create a little boost it could plausibly lower the vacuum.

I did not stay at a Holiday Inn so I may sound like an idiot. If so just tell me.

[376LS3]

If you rev the engine, you are decreasing engine vacuum which is telling the bypass to start closing, which is allowing some air to go through the rotors. Like i said, rotor speed has nothing to do with vacuum as long as your actuator is working correctly. I would absolutely double check your lines going to and from the actuator. Something has to be crossed.

[fourmz]

Might also want to check the grommet on the booster itself. I had one split on my 2008 Silverado and cause a slight leak. cant hurt to check.

[PQ]

Originally Posted by 376LS3

If you rev the engine, you are decreasing engine vacuum which is telling the bypass to start closing, which is allowing some air to go through the rotors. Like i said, rotor speed has nothing to do with vacuum as long as your actuator is working correctly. I would absolutely double check your lines going to and from the actuator. Something has to be crossed.

I'm feeling like an idiot right now. I knew how it worked because I zip tied it open a few years ago when I like my son take it to Homecoming. With the actuator open it can only recirculate and not boost.



I"m actually guessing manifold gasket leak. I'll find out tomorrow.

Originally Posted by fourmz

Might also want to check the grommet on the booster itself. I had one split on my 2008 Silverado and cause a slight leak. cant hurt to check.

It does look good.

[Chevy Fanatic]

Originally Posted by PQ

Also sprayed mucho propane gas in that area when testing for leak. BUT I'm going to go at it with some with some carb cleaner next.

Keep in mind carb cleaner and painted surfaces do not play nice together. You have a lot of painted components that have the potential of becoming damaged by the carb cleaner.

[PQ]

Originally Posted by Chevy Fanatic

Keep in mind carb cleaner and painted surfaces do not play nice together. You have a lot of painted components that have the potential of becoming damaged by the carb cleaner.

OH I was careful. haha

But there is just simply no leak. Must be in the tune.

So my next move is tune.

[VADER SS L99]

I don't think I have ever seen anyone with as many car problems as you PQ. I can remember you having problems with your car back in 09 or early 2010 when it was new and it seemed as though they never stopped. I feel for you bud. Hopefully you get it sorted out. I think Gremlins came with that car from the factory or some kind of bad luck spell got put on it or something. Hope you get it sorted out and good luck.

[PQ]

Originally Posted by VADER SS L99

I don't think I have ever seen anyone with as many car problems as you PQ. I can remember you having problems with your car back in 09 or early 2010 when it was new and it seemed as though they never stopped. I feel for you bud. Hopefully you get it sorted out. I think Gremlins came with that car from the factory or some kind of bad luck spell got put on it or something. Hope you get it sorted out and good luck.

haha, Well the new engine and cam needs tuned and I should be ok. Sitting for a year did not help.

Got a funny headlight issue.

Nothing worse for a car than sitting.

[Scott@Bjorn3D]

I think he loves that car. He will probably keep it till he crooks as much blood sweat and tears he has put into her. I always refer to her as the Black Bitch when we talk on the phone.

[PQ]

Originally Posted by Scott@Bjorn3D

I think he loves that car. He will probably keep it till he crooks as much blood sweat and tears he has put into her. I always refer to her as the Black Bitch when we talk on the phone.

It WILL be for sale soon. When I'm done.

I'm going to ask what I think it's worth and if nobody wants to pay it then I keep it.

[se7en]

any luck with this issue

[sbubbaklein]

Originally Posted by fourmz

Might also want to check the grommet on the booster itself. I had one split on my 2008 Silverado and cause a slight leak. cant hurt to check.

There are 2 colors of booster valves depending on vacuum wanted. Cruise the internet for specs.

Any leaks at the booster can cause lack of vacuum, also if the booster pin is a little short or long it can cause concerns usually brakes dragging. You can try a couple of washers between the master cylinder and booster, look for an improvement. Most European turbo cars have a small electric vacuum pump and vacuum tank since they lack ported vacuum.