snoopster76

Can anybody explain how the external waste gate actuator works?

How the switching actuator works?

How the blow off valve works?

Maybe then I can figure out the problem I'm having with the blow off valve.

Also after removing the air pump, egr valve and the valve the air pump goes to, what do you do with the connectors, cut them, jumper them,???

snoopster76

cant anybody help me out with this info, i'm new to the rx7 world. thanks for any help.

HAILERS

The bests I can do for you is to refer you to the FREE DOWNLOAD of the factory manual at http://www.iluvmyrx7.com where if you look at section 4B, FUEL AND EMMISSIONS , there is a brief description of what they do and how to determine if they are good. It'll give you something to do till someone answers your post.

hypntyz7

External wastegate actuator work s off boost/vacuum. IT has a spring inside, which is calibrated to stock boost levels, like 6psi or something. So at 6psi the vacuum pulls the valve open(against the tension of the spring) adn allows the extra exhaust to pass onout, instead of continuing to spool the turbo. Simple enough, right? Thats how a boost controller works...you run it between the vacuum line and the actuator. It is just another valve, that restricts boost to the wastegate actuator. So if you get to 10psi, then it will let the wastegate actuator see 6, thus upping the boost to 10, or whatever you choose. ITs just another valve, in front of a valve,, meanto tofool the other one into thinking its boosting less than it really is.

Switching actuator..I asssume you mean the twin scroll thingy...cap off the boost line and remove the flapper door inside the turbo manifold.

Blow off valve...has 2 openings to vacuum(well, 3 on the stock one). One Is the small line, that is the trigger. IT goes to boost vacuum fromt eh manifold. IT just controls the valve. IT is normally closed. When it sees a very high pressure level(when youre boosting and let off, closing the throttle plates against the boosted air and causing a shockwave) it tells the valve to open. The main 2 ports of the valve, one is subject to compressed air(right after the turbo) and the other end goes back into the intake, just behing the airflow meter. So when this valve opens, the compressed chockwave of booost travels back into the uncompressed intake side, harmlessly. IF not for this, if you were boosting and let off suddenly, it would soon damage your turbo due to the shockwave. Aftermarket bov's vent into outside atmosphere instead of back into the intake, usually.

snoopster76

hypntyz7,
the switching actuator (twin scroll thing) is under the wastegate actuator and is attached to the little arm that goes into the manifold right. you said remove the flapper door there. What will that do. also, if i plug the hole in the intake tube and let the blow off valve vent out into the air what would that do? Thanks for the info.

relvinnian

...but I have a question.

You say the stock spring is set to like 6 psi, meaning it controls your boost, but when you open up the exhaust (no cats/catback), the stock boost levels can raise from 3-6 psi (because of alleviated back pressure). The fuel cut defenser is not like a boost controller valve, it just fools the ECU into thinking you're not getting higher than stock boost (as you know). But, if wastegate has a 6 psi spring, wouldn't that negate the need for a FCD? You wouldn't be boosting past stock levels, therefore no need for more fuel. That is the only thing I don't understand... I'm sure it has something to do with the backpressure =)

-Brian

P.S. - Don't make me look TOO stupid when you respond, thanks

tims

when the exhaust system is improved the small hole that is the wastegate opening is now too small. it does not allow enough high pressure exhaust gases to escape the turbine housing. this causes the turbo to keep spinning and producing boost. this is commonly refered to as "boost creep" this is a very real and potentially disasterous(meaning engine destruction) problem. to removethe "twin scoll flapper" you would need to remove the turbo and exhaust manifold and cut off the arm and tap and plug the resulting hole. if the stock computer is used just make sure it is operating correctly. venting the BOV to atmosphere should not be a problem it wont sound like the aftermarket BOV's though. also anything that fools the ECU to think there is less boost than is actually present has the potential for detonation and detonation will mean a new motor. be very careful with modifications to this car as the ECU is very limited and the potential for damage is very real.