does the 13b engine in the 85 gsl-se cars have 6-ports or 4? if 6, how are they actuated?

 

6 ports actuated

 

Actuated by exhaust backpressure.

 

what exactly happens to make them open?

is there some sensor somewhere or what?


also, are 12a's 6 as well? like from an 83 gsl..

 

12A's are 4 port except a few rare Japaneese ones.

 

The actuators are connected to the exhaust by a tube. At around 3500 RPM there is enough pressure to activate the ports. The pressure from the exhaust pushes on a diaphragm in the actuator. This causes a shaft to rotate and open the ports.

-John.

 

The fun part is when you go to a free-breathing exhaust, and the 6-port actuators don't get enough pressure (2psi?) to work, and the 6-ports never open... that's when you see people wiring them in the full-open position.

 

Yes, they do. But if you keep the air pump you can use it to open them in the "proper" manner.

-John.

 

just to be sure, this tube that connects the exhaust to the actuators is NOT the SAP, correct?

 

It taps into the split air pipe on the cat side of the check valve. It's a rubber tube, like a vacuum line.

-John.

 

hmm... i must have missed that.
all the SAP's ive seen went straight from the exhaust pipe to the bolt-up fitting on the engine.

don't suppose anyone's got a pic?

 

i have a 84 gsl-se with a 91 6port and i cant get my injectors 2 open

 

you know this thread was 6 years old? use the search button you can learn a ton

 

hey go threw some of my old posts i have quite a few good things on the port actuation if you would like to check it out i use the air pump to do mine. there is a write up on it also you could look in to doing the S5 mod that uses what they call RPM controller to tell it when to actuate
but check out my old posts they will help out a lot