cls6888

SPLIT AIR PIPE - this is the air pipe that injects air into the cat. With the cat gone, you can remove this sucker. You don't have to cap up the hole if you remove the air pump - with the air pump gone, that hole is just dead space - it's not a vacuum leak or anything. But, capping it can lead to a cleaner look.



----- Ok so im looking to remove my cat...my question is do I have to remove the air pump or can i keep the air pump and just cap the end of the split air pipe?

jgrts20

s4 or s5?

cls6888

S4 turbo II 87'

mrslysly

i am also looking to remove the cat and split air pipe. i have an 86 n/a. From what i've read i can remove the acv and air pump, but from looking at the engine, the air pump feeds the 5th/6th ports. Am I seeing that right?

cls6888

Ok so I take it I remove the pipe and cap the hole up on the engine... What would be best to use to cap this hole up with??? thanks

DriftingB26RX7

iTrader: (4)

block off plates people...call mazdatrix (526) 426-4460

cls6888

I still have air pump would that mean the split air pipe hole on the engine would need plugged...or could i just leave it open??

jgrts20

you could leave it open but I found that if you do that then you'll get some engine smell inside the car. I finally plugged mine and no more smell in car. BTW what are you gonna use to open your ports, I believe the turbos were the same as the n/a's on port opening(correct me if im wrong).

cool_as_crap

the 5th/6th ports on the s4 are opened by the split air tube. on the s5, they are controlled by the air pump.

so, for your s4, just removed the air pump and keep the split air tube for your ports. yes, mazdatrix.com has block off plates. just make sure you do take off the cat before you remove the pumpe, else it will melt your cat.

cool_as_crap

the t2's are 4 port motors, n/a are 6 port.

jgrts20

thanx wasnt sure.

Dinnercoat

Is there anyway to rig the 5/6th ports to open up with little electric actuators or something instead of using exhaust backpressure or an airpump?

Or I guess rather anything is possible, but has anyone done it?

Looking for an easy solution to swap between cats/presilence+pipe/cats for emissions but still retain fully functional 5/6th ports on an S4.

cool_as_crap

i have a thread for you:
https://www.rx7club.com/forum/showthread.php?t=121833

also, looking at jgrts20's sig, he seems to have it done.

jgrts20

I converted to electric ports yes and ive posted many times on how to do it. With my setup it runs perfect and it wasnt really hard to do. Do a search on my name under ports and if you still cant find the link on the way I did it PM me.

cool_as_crap

thank!
il be lazy and just pm you

mrslysly

since the split air tube runs from the cat ( assuming it uses backpressure to operate the 5th/6th ports) won't removing the cat render the aux ports inoperable?

papiogxl

iTrader: (6)

my cheap electro-port actuator 5/6th port actuators

cls6888

i have a 87 turbo II i dont have to worry bout ports correct?

'89Vert

Nope...s4 turbo's only have 4 ports

cls6888

therefore i can just completly remove the split air pipe along with the cat and block the engine hole up and be done? :-)

Syncro

iTrader: (1)

Yes. You should probably switch to electronic activation if you plan to replace the cat with a straight pipe.

Certain aftermarket exhausts (such as Racing Beat) still activate 5\6th ports on S4 NA's. More info:
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/racing-beat-exhaust-question-pics-525896/