exhaust system ideas

[stecz]

I am working on my US Exocet (1994 Donor). My donor exhaust system, at one point had the catalytic converter replaced and they chopped the flange off of the downpipe and welded the cat to it.

The problem is that the cat hits the bottom framerail, so I can't use it as is to get the car running and then replace the complete exhaust system at a later date.

I can get a replacement downpipe (used) for $50 at most, and then a direct replacement miata converter for (new) $137 or so. That's still half the price of a full length header.  What I want to make sure of is that if I get the replacement downpipe, and a OEM style catalytic converter w/ flanges, Is everything going to fit within the framerail?  

Also, on exhaust system.  Should I be able to use any reasonable Miata cat back exhaust?  Of do I just need to plan on going full custom?  (basically concerned about how it will fit in the back behind the subframe).

Any good suggestions on reasonably priced kits that folks have used?

Thanks,

John S.

[mdizz7]

I replaced the cat with a cat detele from OBX www.obxracingsports.com/products.php?pk=857 to tak e place of the cat to clear the frame. We don't have emissions on kit cars in Colorado so no cat is fine here. Otherwise you can go with a high flow cat replacement. I also got a cat back exhaust system and for the most part worked fine until you get to the back of the car. Miatas are longer in the rear then the Exocet so with some cutting and welding I made the muffler fit. I also had to cut the stock hangers off of it Exocet the rear that mounts to the subframe. I also put an exhaust strap on the very end to give it some more support. Turns out recently my muffler's internals were ratlling around so I'll be having a new muffler made. I bought the kit used and was only planning on using the mid pipe and not the muffler but it seems to work fine. I'm going to get a replacement made that is set up the exact same way.


Way to long!



Finished

[mdizz7]

Also forgot to mention mine is also a 94 donor using stock header.

[jon]

You will have a hard time getting the original cat to fit.

I got the Enthusacar exhaust and their high flow cat fits easily. Pricy, but nice.

No emissions test for me, but my conscience dictates I keep the cat

[stecz]

Ok... I think I'm going to try and find a used downpipe and cat locally (try to get one free from someone who has done a header, if not, get it from Treasure Coast Miata.
Thanks for the lead on the smaller Enthuzacar cat. In a few years, I will be smog exempt, but it still has to pass a visual, so I want to keep the cat.
I think I'm going to go with the Flowmaster DBX kit. The exhaust is pretty plain, so I might have to paint it, but the tip is just a bent pipe, so it looks like I can cut it where ever I want, maybe just a sideways pointing stub out of the muffler.

Thanks for the help. I'm getting close. Hopefully I'll have this thing on the road soon.

John S.

[jwagner]

Since you're looking for ideas, here's what I did:
mevowners.proboards.com/post/86185/thread

The fit isn't great, it's stuffed in there pretty tight, and the forward rear subframe chassis brace doesn't clear the resonator, but it's a good temporary solution. The high flow cat fits fine.

The combination of the cat and the resonator make a muffler unnecessary as far as I'm concerned, especially on a turbo car (mine is not, but my '94 Miata is). YMMV as to how loud a car is acceptable for you.

[jmills]

If you have a new style frame I think you need an NA doe pipe and exhaust to clear. I have an older version with the wider tunnel so it wasn't an issue, but you may want to do a quick search to guide the aftermarket search to make sure what you get fits.

[golden86]

Here is mine

You can see the build of it here
mevowners.proboards.com/thread/6971/mikes-chicago-build?page=4

The muffler is an aftermarket dynomax for a newer jeep wrangler