i'm looking for a pic of a stock TII exhaust from the Y-pipe to the mufflers. also wanting to know what the differences between the TII exhaust and the NA exhaust is from the Y-pipe to the mufflers. here is a pic of an exhaust. anyone know if its a TII or NA:

 

This was the closest I could find to a definite answer:

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/stock-na-catback-exhaust-different-than-t2-394606/
I also came across some mention of the NA mufflers being round, while the TII ones may have had an oval shape more like Racing Beat's. I wish I could remember what exactly they looked like on my TII, as they were the originals until I replaced them w/ RB mufflers. I do know that my TII mufflers did not have tips on them like those in your picture; just straight pipe of set diameter. My vert's stock mufflers did however, but I don't know if they were factory or not. They were welded on similar to your picture.

 

(edit: I think) that's a TII cat-back.

There could be variances, but my S4 N/A's y-pipe is round tubing, and my S4 TII's y-pipe is the stamped boxy style that you've shown.

 

My 10th AE DOES have factory chrome tips like that.

 

That is the heat shield. Both NA and TII y-pipes had that; mine did.

 

Well interesting. Sounds like the answer is again unknown.

 

the reason i ask is because i'm wanting to buy these for my 10AE. if they are NA i really dont care because the car is just a cruiser and will never be raced and i dont care about making gobs of power. i just want to make sure if they are NA that they arent too restrictive due to smaller diameter piping or different mounting locations. my 10AE currently does not have ANY mufflers. the y-pipe is pretty rotten and the main cat is not in good shape. the pre cat off of the turbo is nice though. so i plan on replacing the main cat with a stainless straight pipe. i cant afford a new cat from mazda..they retail for over 2K!!!!!!!!!!

 

That's a factory system as you can see the shield on the Y pipe and the covers on the connecting end of the mufflers, along with the oval design, but can't tell if they are Turbo or N/A. The chrome tips are factory on all RX7s. Even though I still have the OE system on our '89TII, the chrome tips rusted, so I removed them and installed aftermarket chrome tips.

If you have the car stock, you'll need the main cat so the air tube can be connected. When I did the engine/clutch on ours, I removed the pre cat and purchased a 2.5" downpipe, leaving the main cat in place. It makes working on the exhaust much easier without that monster precat in the way. I presently have the factory main cat back on the car as the Bonez cat quit after 7 years and about 30,000 miles.

 

i have the air pump off due to replacing the turbo last summer and the air tube snapped off the cat. since its a four port i didnt think i needed the air tube as it does not need backpressure for any 5th and 6th ports. the air pump will eventually go back on and if i find a nice converter and air tube i will be more than happy to use it!

 

The restriction from N/A to T2 would be miniscule.. It would probably assist you from overboosting..

BTW I sold my stainless N/A stuff..

 

that may very well be true. i think i'm going to spring for this setup. better than what i have now.. i'll post a pic of it tomorrow..

 

From what I've gathered, the NA and TII mufflers have the same pipe diameter, but the NA versions had more baffling. As mentioned, they'd be tiny bit more restrictive, but that doesn't seem to be a concern for you. Go for 'em. You'll even get all the whole mess of heatshields all over everything for that stock look!

 

Specific answer to your question:

Pictured is a S4 NA stock cat back. All TII exhaust cans were oblong, not round. Further S5 NA exhaust cans were oblong, not round. In all cases, the stock Y-pipe was 2 1/2 inche's.

 

ok cool, still should work on the TII i'm guessing

 

well, i went ahead and sprang for the exhaust. i'll keep you guys posted with pics when it arrives and let you know how everything bolts up and sounds. i'm hoping i made a good choice with these parts.

 

i'll post a video once i get the exhaust on. i ordered all new gaskets from the dealer today.

 

exhaust arrived yesterday. overall i'm pleased with the exhaust. i'm going to clean it up and see how much i can get done on it today. maybe even install it if there's time. pics will be posted

 

with the help of 82transam who is visiting from New Jersey, we got the exhaust on today and i think it sounds pretty good. i made (with the help of some machine shop friends) a cat replacement pipe for the main converter. it was rotten and clogged. i removed the pipe from the pre cat to the test pipe and sanded down the flanges on a large belt sander and made sure they were perfectly flat and that there was no warping. i also shot blasted it and bead blasted it to ensure the rust was gone. painting it is next. all gaskets were replaced with oem gaskets. at any rate on to the pics:

newly used oem y pipe:



pipe from pre cat to main cat ready to be installed:



flat and clean flanges on the pre cat to main cat pipe:



test pipe:



new oem gaskets:



exhaust on the car:









will post a short video next...

 

 

one last video from the exhaust install that i forgot to post. i'll drive thec ar and take another.

 

At idle, it almost sounds like you put some pistons in there. There's a pretty good lope to it.

 

not sure why it runs with that lope. it sure is quick though, lol.