whos really right about 5th and 6th ports?
 

about removing the ports entirely, i remember a long while ago i read a thread discussing this and somebody or some people said when you remove them you get an increase in performance everywhere... others say you gain hp but dont lose AS much tq.... then there are some that say you lose everywhere... the reason im asking is because im getting headers and an exhaust on my 88. i have searched but the thread always ends before a conclusion is made... so my question is who the hell is right.... i already do not have the air pump and acv and mine work fine but i still have the stock exhaust.... i need to know so i can do something, i like the idea of removing them because i do not want to wire up a pump that would open them....

christopher

some ones about to lose a head, a hand, some kind of limb.....

what ever you do dotn take them out, worst mistake i ever made. leave them functional. dotn wire them open or tale them out, you will lose all of your low end. i wish i still had function 5th and 6th ports

dont remove them, figure out another way to open them instead of backpressure or air pump, kevin landers hooked up the motor from a 12V air compressor to my 6 port/VDI the motor kicks on under a load above 3800 RPM's and works the 6 port/VDI. i love it, talk to him about it or have him do the same setup on your car, i dont think you'll regret it...

Well.

Logically you will lose and maintian(not gain) in areas.

Mazda did the dynamic port for a reason.

It stays closed at low RPM's to help achieve torque.
Later on in the range it kicks on and allows more velocity/air to come in to help create horsepower.

So by wiring them open.
You redce your low end torque and maintain your top end power. You don't gain anything from it really unless your modified.

I've seen no good come out of wiring the ports open. If you go with a nice header/exhaust system then you will still have exhaust pressure to open the 5th and 6th. I recomend the RB header and presilencer. Like mentioned above the ports work like they do for a reason.

i was wanting to do away with any kind of cats.... and im getting the RP 50mm Cat-back - 86-91 from rx7.com... i do not think this setup will create enough backpressure

so my setup will be.....

racing beat header --> plain ole I pipe --> RP 50mm cat back

any luck with this you think?

I don't know I've only dealt with S5's. But I hear a racing beat setup will give you no grief. A buddy of mine has a RB header and presilencer and he has no problems at all.

he said he wont be using a presilencer. now about those ports. I have wired mine open since day one. ofcourse my car is pretty modded at this point. wire them open for a while. if you like it, take em out. if you don't, put the air pump on or talk to Landers. I just gutted the stock manifolds and ported them and matched them to each other and the ports in the irons. I have had so many problems that I have no idea what worked better. You do lose torque, but its only a little from what my ass dyno says, and besides, what kind of owner are you? Do you really want torque? buy a navigator. me, I wanted high horsepower, crazy fast responce, and screamin revs! I'm not gonna stop till the neighbors kill me or my car morphs into a Kudzu. I get off work either way.

ill try that james ... thanks

<sigh>

If you do remove them or wire them open, do something about the port profile (in the case of removed ports, this would have to be done during a rebuild). For wired or normal ports, Pineapple racing sells port sleevs that have been contoured.

The problem is that with or without the ports, the air hits a 90-degree wall on the way in. That creates turbulence and slows down air flow.

Personally, I wouldn't want to run an NA without functioning ports again unless it was a track-only racecar that was never going to see under 4000 rpm anyway.

Been there, done that, it sucked.

...... you do not lose all of your low end when you wire them or take them out, yes you lose some, but not a lot, i drive mine everyday with open ports, i live at 6500feet elevation with tons of hills. removing them completely isnt very good, but works, there is a ledge when you remove them that the air hits and creates turbulence right at the intake port in the engine. working ones are best, yes, but if you have pineapple sleeves in open position, you lose almost no low end, and dont have to worry about them working right :)