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-   -   Crazy Auxillary Port Idea (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/crazy-auxillary-port-idea-62456/)

rico05 03-16-02 07:51 PM

Crazy Auxillary Port Idea
 
What if someone wired one open, and left one operational? Any good, bad ideas about this. I really enjoy the quicker revvs of not having the ports functional, but I damn near have to burn the tires stoplight to stoplight to keep from bogging down!! Plus, my RB header, RB presilencer, and N1 single, will knock off torque even more, once they come in the mail that is!

jeff_oner 03-16-02 08:00 PM

one of my aux ports is stuck open. I have no, low end power to speak of, but once I get past about 3500 rpm it feels normal.

rico05 03-16-02 08:11 PM

So I guess it is all or nothing. Darn.

rico05 03-16-02 08:55 PM

Any comments from the Guru's?

scathcart 03-16-02 09:00 PM

bad idea. Those ports only lead to one rotor.
The metered air would be metered by total volume, not per rotor. So the air metered would be divided between both rotors evenly.
the injectors would fire the same to both rotors.
Before the second port opens, one rotor would run rich, and one would run lean.
Lets say you wired open the rear. So it has an extra oprt open at idle, and thus more air flowing into it. but the engine sees total volume, and thinks since the ports are equal front to rear, they both fire the same amount of fuel into each side. But the front is seeing less air, so it runs rich, wheresas the rear is seeing more air, so it runs lean.
Might shudder, bog even worse, or whatever, but nonetheless not a good idea.
Sean Cathcart

RETed 03-16-02 09:02 PM

You need the understand the concept of intake velocity.
The reason you have good low-end power is due to intake velocity.&nbsp You want to get the intake velocity as fast as possible (up to the point it hits supersonic).&nbsp Velocity is directly related to the size (how small) your intake passages are; airflow being constant, the smaller the passage, the higher the velocity - Bernoulli's Theorem.&nbsp You can also coax velocity by lengthening the intake runners.

NOW, if smaller and longer is better for low-end power, HIGH END power is exactly the opposite!&nbsp You want a bigger port with shorted runners, because at high RPM's, the engine is sucking enough air that velocity is not an issue - all you want is VOLUME (as much air as you can such in as possible)!&nbsp Now, this is the reason why you have primary and secondary passages - more so with the 6-port NA design!&nbsp Think about it - the switch is just to let more in at high RPM, and keeps closed to keep intake velocity up by keeping it in the other 4-ports at low RPMs.

Opening on of the 6-ports is just going to make the engine lopsided and does not give you any advantage.&nbsp A working 6-port system works the best, period.



-Ted

rico05 03-16-02 09:10 PM

Now I have to reinstall everything to make em work again!! The shitty thing is, I broke one of the sleeves when I wired it open! I broke off the little piece that goes to the actuator, so looks like I got some work to do!!!!!!!!! Damn it....

rx-7fc 03-16-02 09:27 PM

how would a car run if both of the sleeves are out

scathcart 03-16-02 09:41 PM

run fine.
but....
Higher top endpower, but big loss on the bottom end. Need to rev higher to leave, and you will more then likely bog off the line.
If they work, leave 'em in
Sean


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