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-   -   Working on a custom metallic substrate cat for the FD (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/working-custom-metallic-substrate-cat-fd-425779/)

a3dcadman 05-24-05 03:20 AM

saw your unit on ebay - 14 bids at $105.50 from xenonlighting. has it been tested yet.
chuck

Narfle 05-24-05 05:40 AM


Originally Posted by J_J
Adding an airpump tube shouldn't be too difficult to do; however, I've been told by the manufacturer that these new metal substrate cats can run without an airpump hookup.

its an emissions thing for me. id like to fail visual but actually pass the test. i think im going to get one fabbed for myself except with an airpump tube and 2 metal cats.

ptrhahn 05-24-05 08:43 AM

I'm very interested to see some real dyno info on these. If they can flow at or very near what a resonated midpipe does, I'd be tempted to do it.

I'd just run it airpumpless 99% of the time for smell alleaviation, and then slap on the airpump (with port welded into the cat pipe) to pass the test every two years.

I've gotten used to midpipe power though, I don't think i'd do it if there's a significant drop.

J_J 05-24-05 03:15 PM


Originally Posted by Barban
its an emissions thing for me. id like to fail visual but actually pass the test. i think im going to get one fabbed for myself except with an airpump tube and 2 metal cats.


I got a request for a cat with an airpump hookup and will be having it built next week. It isn't that hard to have it installed, but I think most people outside of California with heavy upgrades are not running an airpump.

J_J 05-24-05 03:16 PM


Originally Posted by a3dcadman
saw your unit on ebay - 14 bids at $105.50 from xenonlighting. has it been tested yet.
chuck

Not at the moment.

maxcooper 05-24-05 03:25 PM

5.0 Mustang magazine did a test a while back with straight pipes, known-high-flowing ceramic cats, and some metallic cats. There wasn't much difference between the 3 in the tests, but they were using two 2.5" cats on a 370WHP car, IIRC. The difference was 10 HP or something like that. Don't take these numbers as gospell, as they are from memory and may be a bit off.

-Max

J_J 05-24-05 03:26 PM


Originally Posted by ptrhahn
I'm very interested to see some real dyno info on these. If they can flow at or very near what a resonated midpipe does, I'd be tempted to do it.

I'd just run it airpumpless 99% of the time for smell alleaviation, and then slap on the airpump (with port welded into the cat pipe) to pass the test every two years.

I've gotten used to midpipe power though, I don't think i'd do it if there's a significant drop.

I believe there have been tests of metal substrate cats already, showing a Knightsports metalit cat as having comparable horsepower gains as a midpipe. The same technology - a metal substrate cat section - is being used in this cat. I can't quote any hp numbers yet since I have not put it on the dyno, but I think I will have the highest flow cat on the market for under $300. Actually, I have not seen any main cats for under $300 new, especially not one using this newer emissions reduction technology.

MichaelFregoe 05-25-05 10:22 AM

Flow on this thing
 
I am deeply interisted in this. I am currently running a Stock Converter on a very modified car.. Mainly to prevent boost creep but secondary for noise control and lastly for smell.

Would this setup provide just enough back pressure to prevent boost creep?

Can whomever does the dyno testing look in to this?

Thanks

PureMdMa 05-25-05 11:53 AM

I was just bidding on one of these on ebay and the auction was ended early and Item pulled, Is this you selling these on ebay J J? if so why did you end the auction early? Im interested in getting one of these. I can get dyno numbers shortly after sale also.

David Beale 05-25-05 12:51 PM

Just ordered the 5" metal wound one from Random to replace my midpipe. As has been reported, it smelled ("normal" for us old pre-cat years guys - "bad" compared to most other cars). It is also a little noisy, though it doesn't attact attention - well, not more than any 3rd gen RX-7 :-) . I have a stainless downpipe and HKS Superdragger cat back (the earlier more restrictive one) for comparison. We're having an O2 bung welded into the top of the pipe 7" from the front flange for tuning. The whole thing is stainless. It's an advanced cat type that doesn't need an air pump. Read up on cats and you'll see what I'm referring to (I forget the proper terms).

Oh yeah, I also wanted a little more restriction for safety. Not sure if my PFC is fast enough to keep the boost under control. I "may" have overboosted once passing a truck up a steep hill in the mountains (heard the "death rattle"), but the engine is still fine two years later.

I do work for the "Canzoomer" RX-8 guys and this is through him (Maurice).

I will post pics. if you're interested. I don't think I'll dyno it though. I can do a G-TECH comparison if you like.

J_J 05-25-05 01:49 PM


Originally Posted by PureMdMa
I was just bidding on one of these on ebay and the auction was ended early and Item pulled, Is this you selling these on ebay J J? if so why did you end the auction early? Im interested in getting one of these. I can get dyno numbers shortly after sale also.

There's a minor problem with my ebay account and I will be relisting the items again tomorrow. I sent you a PM, btw.

a3dcadman 05-25-05 06:29 PM


Originally Posted by PureMdMa
I was just bidding on one of these on ebay and the auction was ended early and Item pulled, Is this you selling these on ebay J J? if so why did you end the auction early? Im interested in getting one of these. I can get dyno numbers shortly after sale also.

i was following the bidding on ebay and it seems that all the items you had listed were pulled by ebay. so whats up.
chuck

J_J 05-25-05 11:55 PM

There was a problem with billing. The card I had linked to my account to pay seller fees was cancelled a few weeks ago when I lost my wallet. I didn't remember to update my account with a new credit card, so ebay cancelled my auctions and notified me that I need to update my billing info. I just updated my info and everything is back up now.

MichaelFregoe 05-26-05 10:01 AM

Has anyone done tests on this yet? HP? Boost creep?

J_J 05-27-05 06:05 PM

PandazRX7 is local to me and should be both smog and dyno testing the cat next fairly soon. I've had about nine of these catalytic convertors shipped out so far but have not heard any feedback from the FD owners as of yet, but there should be plenty of info on this custom cat in about a week or two. :)

d0 Luck 05-28-05 04:55 AM

i'm not sure if i missed it, but will your car actually work efficiently without the airpump?

technonovice 05-28-05 10:00 AM

The car will work more efficiently without the air pump. The question is how well the metallic substrate can reduce emissions. A forum member has passed CA emissions with one such converter.

J_J 05-28-05 02:43 PM

Yes, it will be more effective at reducing emissions if the airpump tube is in place. PandazRx7 bought the cat off me and is going to smog test his car soon, so he should be able to provide more info on this matter.

WaLieN 05-28-05 11:49 PM


Originally Posted by J_J
Yes, it will be more effective at reducing emissions if the airpump tube is in place. PandazRx7 bought the cat off me and is going to smog test his car soon, so he should be able to provide more info on this matter.

Will you weld on a fitting for the OE airpump at a minimal cost?

J_J 05-29-05 02:00 AM

I guess I could have that done for a minimal cost, but it seems that most FD owners looking for a very high flow cat have already ditched their airpumps. Or am I mistaken? So far I have not received many requests for an airpump tube. Given the popularity of midpipes and single turbos (which often require removal of the airpump), it appears that airpump removal is pretty common with owners of modded FDs.

rallimike 05-29-05 05:35 AM

I use an electric air pump

technonovice 05-29-05 10:38 AM

I'd be curious to see the emissions numbers on a metallic cat with and without the air pump on the same car. I guess the easiest method would be just disconnect the the wire to the air pump.

ManGaZeRo 05-29-05 12:47 PM

If I was to get this cat and discount the line leading into the cat and just let it dangle. Without removing the airpump would I encounter any side effects?

technonovice 05-29-05 05:32 PM

You mean leave the line open to the atmosphere? You would never pass Calif emissions.

ManGaZeRo 05-29-05 07:31 PM

Thats why I don't want to totally take out the air pump. So when it comes back to smog time I could just put my old cat on and replug the air pump.


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