Hello all,
I apologize if this has been discussed somewhere else, but I searched and couldn't find quite what I was looking for.
I'm pretty new to the technical aspects of rx-7's, and automotive mechanics for that matter. I had an incident last October, where I pulled my '90 GXL NA out of my driveway, and suddenly the car was MUCH louder than it had been before, the sound was definitely coming from the front/midsection of the car as opposed to the mufflers. I didn't have the time/ability to check it out at the time, or the money to have it looked at by a professional, so I parked it for the winter a few weeks earlier than I normally do. Now, I've been planning what to do with it in the springtime, and I thought I'd take a look in case it was something that I could fix myself.
After consulting the online manuals in the faqs on this forum, I got her up on ramps and had a peek, here's what I found:

It looks like the pipe just broke off from the bolt bracket...
I've identified it as being this section of the exhaust (is that what you'd call a pre-cat?):


Now, my question is, what's the best (and cheapest) way for me to fix this problem? Am I correct in thinking that this I either have to weld the pipe back to the bolt bracket, or buy a replacement for this section of the exhaust? Are there any other alternatives I should consider? I'm on a pretty tight budget at the moment, but I'll do whatever it takes to get the car running (relatively) quiet again.
I apologize again as I'm really not knowledgeable about this stuff, but I'd sincerely appreciate any advice you fellows may have.

Thanks!

 

Thats one loud *** ride right there...

Exhaust shop could weld that flange back together pretty quick, granted the pipe isn't paperthin from the rust...

 

eh just run a stright pipe hahahaha, buy a Bonez super Flo high flow cat and presilencer combo, worht the price you pay for 'em

 

If you do not have visual emissions testing in your area, then the easiest fix would be to purchase a downpipe, that replaces the pre-cat. There are a couple different ones available.

The reason I say visual testing, is that the pre-cat is pretty much not used once the engine and main cat is up to temp, and the majority of the emissions processing is done by the main cat.

If you have visual testing or just want the emissions to be OEM, then a new pre-cat assembly would be fine.

I would not try and repair a 10+ year old exhaust system though by welding it back together. It will just break again, or the pre-cat will fail and clog the main cat (causing an even bigger problem).

 

If you have to buy parts, I second the Bonez superflow setup. I had it on my GXL. It was great.

 

There are a ton of people putting new exhaust system on there car. You just need to post a WTB (want to buy) add in the for sale section. a 17mm socket and breaker bar will take the old portion out and you can replace the broken section. Hopefully there is a seller within driving distance. Some may even pay you to take it away(J/K).

The above advice is best. First try the muffler shop. But be prepared to "sold" something.

 

doesn't look rotted out, cheapest method would be to weld it back to the flange by a muffler shop(a reputable one) and double check that all the hangers are in place and not torn or extremely stretched.

 

Yeah like i said (and He ^ said) buy a Bonez Superflow, you won't reget it, it'll be alot better than those old cat that are probably clogged anyways, i got my bonez pipe for $100 slightly used




http://rx7.com/store/rx7/fcexhaust.html

 

Thanks for the advice guys, yeah that Bonez superflo makes me absolutely drool.....

And I have a feeling that I'd end up spending approximately the same money if I were to try to order an OEM replacement through my local dealership.

I don't think I'm going to go with welding it back on, while it would definitely be the cheapest way to go, as it was said, it could lead to bigger problems down the road, and the damned thing is probably all clogged anyway.

The only other option that I'm entertaining right now is to look for a used replacement. Can anyone tell me if the year of vehicle makes a huge difference on these types of parts? IE would an s4 precat fit in my s5? I've talked to a couple of local wreckers who have 86 and 87 sevens but I didn't want to commit to ordering the part if it's not going to fit. I've seen parts for sale online that say they're for 86-91, but I was hoping someone here could share some personal experience. I might end up posting in the buy/sell section, as I see there's a couple of guys parting out some fc's, but again, if the year matters then I'll have to be a little more picky!

Also, I'm going to be needing a muffler replaced as well, so same question, would a stock s4 muffler be ok for an s5? I'm sort of having the same dilemma as with the cats... if I order a new stock muffler locally, it's around $300 (I'm in Canada), and I can probably get a whole cat-back system for $400-500, so I've got some choices to make.

Thanks again!

 

Actually, I had the _exact_ same thing happen to me. A friend of mine has a mig machine and did me a quick favor, zip, zip, zip.. welded it back in about 15 minutes (including the time it took for me to get the car on jack stands, point out where the problem was, him to wire brush it and weld it, and then to get the car back down)...

Happened about a year ago, no problems since.. there wasn't really much rust there on my 86...

good luck!

 

I had exact same problem on my 86gxl. I took it to a specialty-custom exhaust place and they welded it for $25 no problems since.