I hooked up my boost controller and gauge. THey are doing their job. But boosting can sometimes be sporadic. Plus I never get any negative vacuum to the gauge. Only thing that could possibly be causing the no vacuum could be the TCV. Anyone know exactly what this does and how it works.

 

btw TCV = Temp Control Valve

 

I will go ahead and answer my own question for all who reads. The TCV (Temp Control Valve, aka Turbo Control Valve, aka Turbo Control Solenoid) is located in the line going to the waste gates. It regulates air and wut not. Anyway... it seems that it is best to unhook it and bypass it if you hook up a MBC. It will make boosting smoother. When upping the boost, the air pressure is out of its range to handle and it sort of freaks out. Someone on one of these forums said they were getting a noise in their cabin on the left hand side when they hooked up their MBC. It was because they didnt bypass the TCV and the relay that controls it is under the dash to the left, it will click rapidly causing a light fluttering sound.

 

Thanks for updating the post. Very useful info.
Do you have any pics of the setup?

 

Now I do,... Here is my stealth type set up.

Boost Controler


Boost Gauge


Here is the connector peice I used to bypass the TCV


and the BOV (which has the annoying whistle on it (its removable). I figured it would be usefull for atleast being able to hear when it opened up. I have yet to hear it whistle because I swear the BOV never goes off.)

 

hmmm Now I want to do thatto my volvo


thats so cool

 

If you go into full boost the let off the gas fast you can't hear it?

 

No, I have tried. Plus I watched the gauge when doing this and all was normal. No signs or sounds from the turbos ether conserning back pressure. The throttle body is electronicly controlled, I was thinking that had something to do with it. Because it prolly' wont slam shut like a normal TB would.

 

I was driving a TT yesterday after installing new turbo's and I could hear the factory ones by boosting and letting off the gas.

Big you bypass the factory ones?
Are you running both setups?

 

No CBV if that is what you mean?

 

Does that mean you bypassed or no?
If you didn't then that may be why you can't hear the valve it might be to quiet because you have 3 things releasing pressure at the same time.

 

the CBV was replaced by the BOV

 

Oh ok Im supprised you can't hear it.
I hear the factory setup all the time.
Have you connected a vaccum guage to make sure it is receiving vaccum to open? (Or the other way around)

 

Yeah, I did it the "proper" way just to replace the stock CBV. The "vacuum" line in all actuality keeps the thing closed unless the throttle body slams shut. Which who knows when it comes to that because it is electronicly controlled. The way it is programmed hurts mid throttle performance. I can tell that (to put simply) it doesnt put the power out unless you put the peddle all the way down... [holding back from ranting[:'(]]

 

Ok sorry it isn't working the way we think it should.