Hey guys I was thinking about doing a straight pipe this weekend. When i was under the lift looking at my car, i noticed the cat has a rail going out of it which i belive is for the smog pump? Can this be eliminated and how without effecting anything? And what would I tell them to do for the straight pipe or should they just know what to do. Like just have them make the pipe the same diamater as the stock?

 

A quick read of the FSM will tell you that the pipe connects the air pump to the cat (via the ACV) and supplies exhaust backpressure to the aux ports to open them. Cat removal on an S4 NA requires extra steps to actuate the aux ports.

Also, a straight pipe will be ungodly loud.

For the record, the Factory Service Manual can be found in the FAQ For FC thread. It contains all this information and more, and is an essential tool for any sort of service work that needs to be performed on these cars.

Additionally, the Haynes service manual for the 1986 thru 1991 RX-7 (both turbo and NA) can be found at most local auto parts stores or purchased from any good bookstore (ISBN number 1 56392 007 7). It is only about $25 and is a great quick reference for things like this. Not only does it contain most of the information in the FSM condensed into an easy to read format, but it includes full wiring diagrams as well.

These manuals will answer 99% of service related questions for the car and if you intend to do your own repair work, you will need at least one of them. Preferably both, since the FSM is a free download.

 

Loud isn't bad. Pull the air-pump if your going to disconnect it. I have my gxl with the apexi N1 and the bonez race pipe, love it.

 

Listen to AaronCake. He knows his ****.

 

What would be some methods to actuate the aux ports? Im thinking of just getting a test pipe to replace with the cat and remove the air pump.

 

most commonly is with an airpump.

there are several tutorials for this. here is one.

https://www.rx7club.com/2nd-gen-archive-72/how-air-pump-auxilary-port-activation-330310/

Here's another.

http://www.rotaryresurrection.com/2n...actuation.html

try searching, it's amazing, your questions get answered before you ask them.

as for the straightpipe...i have a video of my car running with a straight pipe and a big exhaust leak, and it's pretty loud. search the second gen section for posts by me and you should find it easily.

 

sorry to post jack but i have the rb road race headers out to straight pipes to mufflers i dont have the line for the auxillary ports should i wire them open ? i know i lose bottom end which is ok by me . well hope to hear from anyone . oh yeah and its so dam loud ! but its nice !

 

If you don't care about fuel economy or low end, then yes, wire them open, or you're losing 15-25 hp up top.

A search could have told you that.