hayas-fc

i heard that if you gut the cat. then you have no use for the air pumo and can remove it, is this true?? if so how would this affect my car?

Scott 89t2

if you have an 89-91 N/A you still need it.

Makenzie71

i have an 87 N/A...is it still important?

silverrotor

iTrader: (1)

No It's not Impotant. You still have to have the Auxilliary Ports functionable. Although you are free to do as you may, please don't "wire them open". You really lose more than you gain IMO. You may wanna try this. https://www.rx7club.com/forum/showth...hreadid=121833

Makenzie71

what would it hurt if I jes plugged the port on the intake that the pump feeds?

F1blueRx7

iTrader: (5)

lol, Yes, It would. You'd have a bad hesitation at 3800 rpm from the ports not opening to allow more airflow. I'm going to be going with pineapple sleeves ( www.pineappleracing.com) and a streetport when my engine gets rebuilt.

silverrotor

iTrader: (1)

Crap! I meant to say yes- you need the Air Pump. Otherwise you'll smoke the Cat(s).

Why if you have an 89-91 N/A you still need it? I don't get It. 86-88 Is no different.

jeremy

iTrader: (1)

i thought the 86-88 used the airpump for the 6th port actuators.

Ryde _Or_Die

Ok lets set this straight:

All TIIs: only need air pump to supply fresh air to cat

86-88 NAs: only need air pump to supply fresh air to cat

89-91 NAs: need air pump to supply fresh air to cat, but cat also opens the aux. ports(ie: 5th & 6th ports)

dr0x

s4 uses back pressure, s5 uses the air pump.

F1blueRx7

iTrader: (5)

So according to this, I can completely ditch the Air pump, run headers and a cat back with no cat's, AND still have the intake ports open/close properly? how do they work if that stuff is missing?

Scott 89t2

you might not have enough exhuast back pressure to open them.

Jimmy325i

Actually, from what I've seen, most exhausts have enough to make it work, but you'll need some kind of tube to connect the exhaust to the actuators. RB has their presilencer which comes with the tube attached. Not worth the $$$ for that piece if you ask me.

The smog pump can also be rigged to make the 6 ports work and not have any other function. I'm runing that set up right now but think it might be more weight saving to go with backpressure opperation and just make the flange to tap the exhaust and fit it in between the test pipe and header.

Ryde _Or_Die

First, I don't know what kind of car you have. Second, no you can't do that(I assume you have an S4 NA). The S4 NAs aux. ports open using backpressure, which you would not have very much of. I was only referring to what the airpump is used for in each model/year.