turfgrower

I'm new to the RX7, but I've been learning a lot from this site. My RX has had the air pump removed and the air line to the cat disconnected. I believe the exhaust system is stock. So that is my setup. Now, I'm wondering if anyone could help me figure out if my ports are opening or not. I've read that the S4's open due to exhaust backpressure. But is there anyway I can check to make sure they are in fact working. Some people have mentioned that you'll lose power above 3500 rpm. But it's hard for me to judge that when I haven't driven any other RX7's than this one. Any advice?

ddub

If the line that goes to the cat is disconnected, no your aux ports are not opening.

turfgrower

So is this a bad thing? Do I need to be fixing this?

WAYNE88N/A

Look at the back of your engine there, on the right side, there should be a small metal line sticking out right above the exhaust manifold. Is there anything (like a hose) coming off of it? If there is, follow it & see where it goes- the previous owner might have rigged up an electrical air pump somewhere to actuate the ports...

If there is no hose, your ports are inop, for sure...

ddub

Well this means you're running off of 4 ports instead of 6 above 3500 rpm, so yah its bad in the sense you aren't reaching your potential power. You can either hook the pipe to the cat back up and hook the vac hose up to that pipe that sends pressure to the actuators to open, or you can wire your actuators open perminately, or remove the actuators/sleeves/etc from the ports completely and block off the holes that are left. The last two will have the ports being open all the time which will hinder low end torque but ensure that your top end is proper.


I've also read some things about rpm switches or something to have the actuators open at certain points, but I don't know how to do this you'd have to search to find that out.

turfgrower

So having this ports closed for now isn't going to ruin my engine or anything? I do suppose that it's best to stay below 3500 until I get them fixed.

turfgrower

So this isn't going to do my engine any damage soon? It is probably best to stay below 3500 rpm's until I get it fixed though...correct?

ddub

It wont do any damage to your engine above or below 3500 rpm, it just means you're not getting all the performance you could be.

kiyoshi

means it's not fun at all. Even if you don't rev it up hard often, it's better to be fixed. You'll be amazed

ddub

Honestly, I wasn't. I got mine fixed and couldn't "feel" much of a difference. Maybe a slight one, but nothing "amazing." I felt a better top end increase by ripping the actuators/sleeves/rods/etc out completely, but most people don't like to do that.

coldfire

iTrader: (1)

when i got my 5/6 ports working properly, i could notice a slight increase in power after 4000 rpm or so.
but what i noticed more was the change in exhaust note, that is definetly noticeable for me...