Ok so I have been doing a lot of reading and research, but there seems to be some back and forth argues about removing the ACV and using a block off plate with no air pump and not being able to open the 5th and 6th ports.

So here is where I stand I have a 88 gxl and I got a streetable header with o2 sensor and I have a removed air pump and ACV and have a ACV block off plate. The little booster pumps to the left and right (or in front and behind) are also currently removed (I think those are what open and close the 5th and 6th ports?). So what is my power loss or power gain right now? and if I get the racing beat presilencer with the back pressure thingy, and i put those two little booster things on will my 5th and 6th ports work? and whats gonna be the power gain and loss? And how restrictive are those presilencers racing beat offers.

 

Right now, if you leave the ports closed you have lost all your top end power, end of story. If you keep the ports open you will loose some low-end torque and keep your normal power up top. Basically you are loosing something either way by removing your port actuators.

Not to sure how S4 5/6th ports really work, but I do know they are not electronically controlled like the s5's.

CORRECTION: They will work fine if you connect the RB presilencer to the split air pipe, but you would still need the actuators for the 5th/6th ports.

 

The ACV is not related to the aux. ports on an S4. It's semi-related on an S5, but that's only because they tap into air from the air pump at the ACV. On S4, the actuators are normally fed off of the split air pipe itself, just before the check valve. So all you need is a presilencer with a pick up tube and the split air pipe. You can connect the split air pipe to the LIM even if they ACV and air pump are gone. It just won't do anything but supply the aux. port actuators. Also, presilencers are not at all restrictive. They're a big hollow tube with steel wool packed around the sides, which absorbs sound.

 

Good catch, I wasn't sure about S4's 5th and 6ths opening mechanism, interesting.....

 

use a pickup tube or put your factory airpump back on and rig it up to control the aux ports. don't use electric pumps. they work but not for very long.

 

yea i am currently using some hose i connected from the air pump to the ACV and then ran air to the actuator ports and controled it with a valve, but i was mainly curious about the RB presilencers flow restriction, and if it will make my ports work exatly how they should. Also to mention i have a RB streetable header.