The other day after working on my 88GXL, i sat it back down off the lift and started it to let it warm up (cold that day) and after a bit, i notice a bit of smoke from under the car. Turns out the cat was glowing bright orange.

I imagin its atleast partly clogged, do im just going to get rid of it. My understanding is that the pipe comming off the cat suplies the pressure for the 5 and 6 ports to open. Can i just weld a bung on the side to attach the pipe , or does it need a bend on the inside to be in the exhaust stream.

Also, the air pump was deleted by a prevous owner, so im sure thats not helping the cat either.

 

what work did you do to the car? a cat won't just clog up while sitting on jackstands so you may have created a problem while working on it.

 

oh it may have been doing this for a while and i just never noticed... ive only put like 100 miles on it since i got it. I toped off the transmission (input shaft deal leaks) and i was trying to find where my PS fluid was leaking from. Not that it matters, but i work at shop that lets you pull in your own cars on the weekend, so it was on a 2 post lift.

 

well i would inspect the cat and see if it is truly clogged or broken up internally. if it isn't then you likely have other issues that need to be resolved. you would need a baffle in the exhaust to recreate the backpressure needed for the auxiliary ports. RB makes a presilencer that can do this, others have plumbed into the ACV ports to take the air pump pressure to activate them instead.

 

problem is that somone welsed the exhaust together at some point... so its gonna have to be cut out

 

wonderful, i love 10 feet of welded together exhaust.

 

suggestions then? i know it has an aftermarket header

 

chop it and weld flanges back in like it is supposed to have.

 

i dont really need the cat though, right? as long as i can get the pipe for the intake right i wouldnt think it would matter. There is no emmitions testing here, and im going to be using it for autocross and maybe everyonce in a while on a weekend, so noise doesnt matter

 

dont need it, it does help quiet down the exhaust by a fair amount though.

 

so, back to my orignal question, will just a bung on the side work, or do i need a piece with a 9o deg elbow to point into the exhaust stream

 

the closer the port is to the engine the more backpressure there will be. back that far, no a bung won't work.

 

what about in the colector on the header? or just after it

 

every exhaust is gonna be different. no answer i give you is going to be 100% accurate without a way of measuring your backpressure, whether or not you use the split air pipe or not with the smog pump. you're altering the system and there is no definitive answer for what is the best method of hacking it, depending on what parts you use. search what other people have done and test the system after making your alterations to see whether they are opening fully or not.

i'm not a n/a guru, never messed with one extensively(only owned one and not for that long, kept it stock) but i do not mean to sound unhelpful as you are actually trying to keep the ports functioning which is more than most people bother to do.

 

just trying to find a way to make it work without spending $400 on a racepipe with the tube in it

 

here, just read through this thread for ideas. there's dozens of other threads but most any will give you ideas on how to go about it:

https://www.rx7club.com/2nd-generati...k-s4-n-999348/

 

Dude you can wire them up electrically for dirt cheap...

 

that sounds like a plan, is there a how-to somewhere?

 

in the thread i linked, which you apparently didn't read.

 

i did open it, but im on my phone at the moment, so i was gonna read though it later

 

Edit

 

read though that thread and it makes scence. id hate to revive a year+ old thread, so... what kind of electric air pump would i need to get?

 

12v DC

The reason of my edit earlier was I couldn't upload the picture of the pump via my phone,I'll do it when I get home later

(Btw) it is also for sell.....brand new,
I'll try to upload a video of it making the actuators moves

 

4X4 truck air locking diff pump? I think a a pressure reservoir (tank, if you will) with a regulated output would be perfect. A pressure cut-off switch for the pump and you won't have it running every time you get to 3800 RPM.

 

Tony, Have you tried hooked them up the way your saying ?