Yesterday I removed my cat because was getting clogged, but it seems it was still doing its job as a cat. Since I removed it, my car exhaust smells very bad when idling and I can't tell you right now if it's the same on the road. :frown:

Is it going to get a better breath when I'll have fixed my problem of lacking power or is it the natural RX7 breath? ???

By bad, you mean very rich smelling? No, thats normal, hence the reason Im putting a converter back on. Only one though, a high flow, instead of the 3 that were on there. And the racing beat pre-silencer that was solely on there before. There are 3 converters on that car by the way, you only have one??

No, I have 3 cats but the 2 pre-cats were broken inside so I just threw the stuff out last year. Now I removed the 3rd but as I said it's smelling bad. You said you're putting a new cat but high flow, it goes in the place of the 3rd and you have a RB presilencer behind that just before the Y.

I believe that the Racing Beat pre-silencer takes the place of the main converter, its been almost 5 years since I put it on , so Im trying to refresh my memory, it comes with a pipe that goes in place of the other 2, so basically you run no converter, and a pre-silencer, the fumes that come out of the car with this set up SUCKS ASS. It stinks you and your clothes up if you stand behind it, will stink up the house if the wind blows the exaust in a open window, and your car wont pass inspection, never mind visual inspection, it wont pass emissions testing , it will rev a bit better, and even show a slight improvement in fuel economy though. Im going to have the shop that did my exaust ( its all custom after the pre-silencer with Borla mufflers ), take the pipe down, and weld a high flow converter in its place, to be prefectly honest with you, I wouldnt reccomend running no converters on these cars to anyone, its one of those things you do thinking it will increase power, but on a N/A car that is basically stock, its something I feel people regret afterwords due to the fumes.

Yeah...I knew it was clogged and that I could have some smell problem but not that much. I can't put it back since I threw the stuff out like the other 2 and put a pipe through it to be less noisy (so I could re-use the flanges). But this was temporary, I wanted to install the RB Pipe/presilencer kit later. What brand is your new high flow cat?

catco, $60 from summit racing, all the materials used in a converter are the same, this is a "universal" high flow one. Ill see how it works probably in the next week or so when I get my rims back from the polisher and take the car to the header/exaust shop.

I suppose it's in stainless steel. Are you going to get the same efficiency as the original cat, I mean for emission test if you have to be tested. It seems low in price for a cat, no? I'm going right to the web site to see what it looks like. I'm not interested to keep that **** smell either. :(

with every thing good there is always a bad :yinyang: U guys are telling me u gained no power? My car atleast gained 10bhp, with removing my 3 cats, revved faster and past 4k it pulls so much harder, and i also get better fuel economy, but yes it does smell like crap. Sure u guys don't have exhaust leaks? Only ppl who smell it are the ppl behind me, and i never smell it when in my car, only when chillin back by my exhuast.

I did gain power and I'm sure it's not only because the cat was clogged. Judging by the first tests I made, I gained about 25 hp but I'd say that at least 15hp was lost due to clogging. I still have power missing for the expected 146hp though.



What I'm thinking about is 2.5in downpipe and a 3in high flow cat instead of the presilencer.

< I want to live where you live where the wind always takes the exaust away from the car, lol. Sometimes I have to watch if the house windows are open and the wind goes a certain way, it goes in the house. And with a convertible in traffic or at a light, if the wind is going a certain way- it also comes in the car. With the windows closed or while driving, its fine, if there was a leak, I would smell it in the car when the windows were closed. My point is running a exaust on a stock N/A car, I think people should save thier money on the pre-silencer that hardly silences the car anyhow, and invest in a good high-flow cat. Here in New York, cars are run on a wheel dyno and tested, and its on video camera, there are guys who can still pass cars, but if the car is stock, why not have performance and be legal? For example: my cousin has a ZR-1 corvette, the car was made so right from the factory, that even with a $2500 aftermarket exaust on it, it basically ran no different, it just spewed more emissions in the air, so he sold it on Ebay and went back to the stock exaust. To each thier own, but if it means 5 horsepower, im going back to one high-flow over the original restrictive 3 that the car came with.

first of all, your taking piston. Those V-8s usually come with nice exhuast systems to start. On pistons u can't really gain crap from doing exhuast, if seen lots of headers on car even decrease hp by 1 or 2. But rotaries on the other hand gain a lot more than pistons by doing exhuast, they are so restricted and have those thermal reactors. For rotaries to pass emissions they had to do sooo much, thats one of the reasons they don't make em here anymore. 3 cats says a lot right there. IMO its well worth the stinkiesness to gain that hp, for $150 you can't go wrong, u gain more hp from that than anything you'll ever do to your n/a 7, short of forced induction, or porting.

You think all these aftermarket exausts are on the market for no reason? Of course they increase horsepower and help a car breathe. Unless you have a high performance car from the factory, most of them have a quiet exaust, and if its very quiet, it has restrictions. Another piston example: a Mustang GT, you put a H-pipe with no converters and free flowing mufflers, and you pick up about 15-25 horsepower, only because a stock mustang came with 2 resonators, AND 2 converters. But you know what? A Mustang with a "off-road" exaust, still passes emissions, it wont pass visual, but it does pass the sniffer. Why do you think there are virtually no exausts on the market for real high-performance cars? Im not arguing, I felt the same way you did when I put the exaust on my car 5 years ago " ill deal with the smell for some extra horsepower, and it revs better", now I want to have the power, but I also want to clean up the emissions of the car, after 5 years, I cant deal with the smell anymore, and its the "right" thing to do as well. I come home from a day of driving, and my girl and myself stink like a rotory exaust, and Ill be damm if Im going to stink and not have at least 300 horsepower, lol. How long you had that exaust on your car now out of curiousity?

i was a little confused as to what you are saying earlier i get ur point now. I have had it on my 7 for a year. yeah i smelt it today and its pretty bad. I don't ever smell like exhuast though, never, but ppl behind me complain all the time. So what were we talking about again? https://www.nopistons.com/forums/pub...IR All i care about is power though, so i can deal with it. Its just another trade off. I would never put converters back on though, its too much money just to have it smell better and i would lose power, can't do that now https://www.nopistons.com/forums/pub...DIR#>/wink.png.I guess if it bother u that much, u should put a high flo on. Make sure that high-flo cat of yours can handle rotary exhaust temps, which are a lot higher than piston engines. o by the way i have 9 friends here w/ 7s and have been on the forums for a while and this is the first time i have ever heard someone that is willing go and put a converter back on. I still think u have an exhaust leak though. O well, tell us how that high flo goes for ya.

Maybe in a coupe it isnt as bad, also when I first did the exaust, there were no rice cars. Now all these dicks have gone and ruined it putting big tipped mufflers on crappy cars. And to be 100% honest, I cant take the noise either, at certain RPMs it almost cancels out my 10" JL woofer! I have straight true dual exaust with Flowmaster mufflers and custom h-pipe on my Jeep that has a AMC 360 in it, compleate with edelbrock cam, manifold, holley 650 carb, but that has a nice deeeep sound to it. Or maybe its just the fact that because I have had the exaust on for so long, I want to have something different now? Who knows, maybe in a few years, youll change youre tune https://www.nopistons.com/forums/pub...DIR#>/wink.png

NA's with no cats sound a little too high pitched.

< now if you have a turbo to muffle things up a bit, ahhhhhh thats better!

While I don't like a particularly loud car, I can usually handle a loud turbocharged RX-7. MY car is pretty loud right now, but that's because of a bad gasket and a crappy v-band clamp.

I have a spanking new gasket if you desire it

Thanks for the offer, but I need a 3" gasket. https://www.nopistons.com/forums/pub...O_DIR#>/11.gif

I just want to add a comment on what you all said above. If your clothes smell exhaust you probably wouldn't noticed it even if you try to because your nose has cancelled the smell since it catches it all the time your clothes did. But other people who has not smelled it yet will noticed it on your clothes. Same thing happens with snowmobiles, I know that.



On that subject I won't tell anyone what to do since it just depends on each one's priority, a little less power or the exhaust smell.



I'm gonna make some tests before and after anyway and I'll tell you what it'll return from it (for a stock N/A). https://www.nopistons.com/forums/pub...DIR#>/wink.png

dyno results would be nice or are u talking emissions? What kind of tests?

I was talking about power loss. As for the dyno, I don't know if I could get my hands on one. As I've already told you before, it's really hard to find in my area, but I'll try.

If it's not dyno, it's going to be with a performance meter and alot of tests in order to have a good 'picture' (a good average).