wstrohm

I believe that statement is inaccurate. The secondary air pump pushes air not only into the cat but also into the exhaust ports. The O2 sensor sees that extra O2, reporting a lean mixture, but the ECU is calibrated to ignore the leaner reading, since it does not represent the true A/F ratio in the input chambers. If the air pump is removed but the ECU is not recalibrated, the O2 reading will be lower, and the ECU will make the A/F mixture richer than desired.

donz

iTrader: (2)

The Hyundai and KIA? You must see so many performace cars!!! haha


Ok sorry... I'm just joking No offence speedworks, just could help but laugh...

slo

iTrader: (1)

I'm not really that farmilliar about how the OEM FD ECU works, but the only thing the FC ecu's did with the 02 sensor is to use it for closed loop fuel controll. They would not go into closed loop when the port air was turned on. I am fairly certain the FD systems works exactly the same way.

Your statment below is not consistent with how narrow band 02 sensors work.

Speedworks

Please go ahead... I know better :-). too bad the US only gets those gas slurping gasoline engines. The diesel engine perform a lot better, better mileage, cleaner etc etc.

Oh and if you ever get to visit Hyundai Motors Europe or the Hyunda/KIA R&D center, you might be surprised what performance cars you might see there


The fact that cats changed the smell of the exhaust gasses is a thermo-chemical reaction.
I hbought the Bonez HF cat 2 years ago. haven't used it yet because there is no place where you can find the CPU number or anything like that.

Back on topic...

slo

iTrader: (1)

They have some very nice looking cars in there home market in Korea aswell.

Not on Current US diesel fuel, it contains much sulfur which precudes the use of most emission controlls on diesel engines, that is changing soon.

Kento

Just to clarify here: The catalyzer changes the compositional makeup of the exhaust gases by thermo-chemical reaction-- it doesn't "change the smell". That smell from straight exhaust-equipped FDs is excessive combustion by-products that will sting your eyes and cause other ill effects in enough concentration. You can sit behind an idling cat-equipped FD for a while; you won't be able to sit behind a straight-exhaust FD for very long.

Speedworks

Basic line is that the cats offered on the internet or at the parts shop (all the regularly named brands on this forum anyway) do not offer ANY form of R&D background. No numbers, rarely to not a cell amount per unit (CPU), nothing....

The only thing is how much extra horse power it brings... turn it like you want, a cat was never designed to give or take horsepower... so every brand advertising with this argument is most likely not interested in this parts true function.

Kento

Not to continue drawing this out, but you're missing the point here. The vast majority of FD owners aren't buying the hi-flow cats specifically to get some magical horsepower increase or be environmental activists. They're buying them because they offer a cheaper, lighter-- and in most cases, a slight performance increase, whether through intentional design or not-- alternative to the very expensive OEM unit. If "how much extra horsepower it brings" is the "only thing", then they'll just forget about a cat and install a mid-pipe (along with the appropriate methods to control boost), correct? I'm sure the HJS unit is very good, but if power is all someone is interested in, why go through all the trouble of obtaining a surely very expensive cat from overseas that will not provide the power of a MP anyway?

GoRacer

iTrader: (2)

This is true. That is exactly how I have my air pump hooked up (through exhaust ports only). I meant the metalic cat does not need the air pump nor does it have two seperate sections in which air is injected in between the two. Since the manufacturers say air injection is not needed for metalic cat then the only reasoning for company's such as Knightsports to retain the air pipe for the air pump connection would be to be street legal and easy hookup without removing the air pipes and adding block off plates.

FDeez

Knight Sports uses German Emitec Metalit convertors in their some of their HF cats.

http://www.emitec.com/index.php?lang=en&mid=e4&doc=50

http://www2.ocn.ne.jp/%7Eknight78/METALIT.htm

DaiOni

another happy SMB owner here too.

last time I checked they didn't have the data on their website - but if you enquire, they will tell you cell count, emissions data, etc .

Speedworks

Well that's fair enough...

Scrub

iTrader: (25)

Thanks for all the replies! I know this can be a difficult subject for some, expecially o-zone hater Rich. I really like the SMB cat, but wish it had a resonator already built into it like the revo-tune.

Dale, Do you still have the air-pump hooked up to your SMB cat? You said the exhaust has provisions for the pump, but you didn't say if you were using one.
I'd still like some concrete evidence that you do not need the air pump to make the cat happy, like lets say "My cars been using a metallic cat for 45,000 miles with no pump and it's not clogged yet". If I have to I'll get a C4 pump and wire it to run at 9 volts constant and then I know it shouldn't clog, but I'd rather not. It's not about being lazy or anything like that, I just don't want to deal with it if I don't have to. I really liked the SMB metallic cat, but it's missing a resonator. If SMB could add a resonator it would be perfect. The revo-tune piece looks very nice and has everything I need.

Speedworks,
I hate to beat a dead horse, but actually Japanese tuners do make parts to keep cars street legal. One company in particular is Phoenix power, which will NOT tune cars past legal limits, be it sound levels, emissions or factory equipment that must be retained. Phoenix power does all this and still makes very nice powered cars at the same time. Just because you don't see the data listed on the site doesn't mean it hasn't been tested.

To be honest I'd like to see some American tuners taking the same route Phoenix power has. I'm not an eco freak or anything like that, I just know you can make almost the same power and be emissions friendly at the same time. Yes it may take a little more work, but there's nothing wrong with a good challenge.

The reason I want a metallic cat (I have none now) is because I'd like to be street legal all the time. I want to be able to roll into a DMV (I forget what it's called in Belgium) and get a passing test, while making good power at the same time. You're right, none of these cats come with CARB # or whatever, but that’s because modifying the exhaust in any way is against federal law I believe. I'm not an expert on this subject and don't claim to be so if I'm wrong someone please correct me.
When I go to inspection they don't check under my car, they don't know what to look for in the engine bay; they stick a tube in the exhaust and read hydrocarbons and all that good stuff. If the car captain says my emissions are coming out in an environmentally friendly manner, then what does it matter if the cat has been tested? I don't know what sorts of regulations are used for Catalysts, but I'm sure they're all in pretty close proximity as far as performance (exhaust gas cleaning).

Back on subject
Ideally I would like a midpipe with a metalic cat and a resonator built into it like the revo-tune if anyone else makes them. That exhaust is like $700 + shipping from the happy island.

-Dan

-Fin

dubulup

my mission statement

gracer7-rx7

iTrader: (16)

Scrub,

You probably won't get that kind of data from the rotary community. However, you'll notice that those metal substrate cats are used on many other vehicles both OEM and aftermarket. Random uses them on their direct replacement high flow cats on the Vette for instance. I probably have the most mileage out of all the other posters on my cat and it has probably also been the most 'abused' given my rich mixtures, pre-mix, flame-age and all that.

I need to get a mirror so that I can flash it in the mid pipe and see the cat core. Haven't been able to get a good view of the front side given the bend in the mid pipe.

Including the metal cat in the mid pipe by itself doesn't change exhaust note much compared to a mid pipe. Its frickin loud.

Regarding flow and restrictiveness - its minimal. I notice barely any difference between a straight mid pipe, resonated mid pipe or a mid pipe with this metal cat with regards to spool and power. That was on back to back tests on the street. I also used a brand new Bonez for a few miles and it is much more restrictive in spool and power delivery and not as quiet as Rx7 store's mid pipe.

If you want to discuss in person, PM me and I'll give you my cell.

FDNewbie

iTrader: (10)

My bad, I couldn't remember if you posted your name on the forum or not (some ppl don't).

Dan, is *anything* I ever mention cheap? Although some of the stuff I can get good deals on... (but prob. still more than you'd like to pay).

Really? Check out the data below...

That's akin to saying California has one of the worst smog problems in the US, so it's safe to assume they have no emissions restrictions When in fact, BOTH Cali and Japan have VERY stringent emissions standards. The standards in Japan are SO high, in fact, that you have to pay a hefty fine to keep a vehicle registered after 5 - 8 years (as emissions equipment's life expectancy comes to an end). So most people sell their cars at that point and buy a new one.

Well their comparisons are always to OEM, as well as conforming to STRICT Japanese guidelines in order to pass as a legal modification (like Scrub mentioned earlier), including JASMA certified exhausts.

Speedworks, you really should check this out before making such statements. Knightsports posts this info on their website...

***Disclaimer: The following is my own rough translation of Knightsports' data, so the original info has been modified *slightly* where I saw fit for understanding purposes***







”FD800Ti” OEM-Conformity Muffler

The titanium muffler for FD3S. Tested using a VI Type FD via the approach noise method:

- As for 90db and weight normal: 16.3kg→5.6kg.
- Light weight conversion of the overhang section is assured.
- As for output of a VI Type FD: 283ps→303.9ps
- Torque 32.4kg-m→37.1kg-m.
- As for specification main: 80Φ [tail]: 100Φ

It is a muffler of the full straight structure which uses titanium material of t = 1mm. As for the main pipe there is no connecting weld beads; it is mandrel bent. Riveted on the tail is our company logo (on a stainless steel plate) seen below. It is a muffler made for the FD with details kept in mind. It is JASMA conforming.





EDIT: Sorry about that; the graphs weren't showing up in the post, so I had to save 'em as images...

~Ramy
FDNewbie Imports

gracer7-rx7

iTrader: (16)

I finally got around to inspecting my Random Technolgies metal substrate cat that I installed ~2 years and ~10k miles ago. I was totally surprised at how clean the cells of the core look. It basically looks new. Remember that I'm running rich 10.5:1 AFR, pre-mixing (only last 2-3k miles), no air pump (10k miles) and have the regular flame show out the exhaust. I thought for sure that the cat would be at least partially melted but it looks perfect.

I also shook the mid pipe around and banged it with a hammer to try and see if the metal catalytic core was intact and it still is - unlike the people using the Dyna Tech metal cat that had the core separate from the can.

I've been pretty happy with this cat since I've been using it. The flow is pretty good - especially since I'm running twins and normally only run 10 PSI of boost. I didn't notice a *huge* seat of the pants difference in power between the cat and the straight mid pipe or resonated mid pipe. It did spool slightly slower but nowhere near as slow as with the Bonez cat (which I also have). The metal cat alone makes no difference in the exhaust note so running it w/o some kind of resonator/muffler is still pretty loud.

I recently installed a resonated mid pipe w/o a cat to see if I liked it but I'm not digging the fumes so I think I'm going to cut my old Random metal cat core out of the mid pipe and install it in my resonated mid pipe.

If anyone is interested, I can probably get my welder to create a jig and do a few of them. PM me if interested.

TRISPEEDFD3S

iTrader: (26)

Hey Ramy the "OTHER COMPANIES PRODUCT" is A`PEX-i HAHA. A`PEX-i uses the 130 cell. Man, I would have thought the A`PEX-i would have performed better since it was longer. I guessed wrong. See that GoRacer! We were both mislead by the length of the cat. Damn, Corksport sells the Knight Sports Unit for like $846. Nengun sells it for $1,022 shipped. I KNOW Ramy can get it to you for cheaper. Scrub, is your car that loud tha tyou need the resonator on it? That Revo Tune unit is nice as hell though. I also like the fact you can also have a 90mm option.

TRISPEEDFD3S

iTrader: (26)

Gracer, PM me with how much for everything, so I can keep it in mind. What resonator ar eyou going to use?

gracer7-rx7

iTrader: (16)

Probably one of the Magnaflows. I have a collection of mid pipes & cats including:
1- regular mid pipe with the Random metal cat
2- rx7 store resonated mid pipe
3- Bonez cat (w/ 50 miles on it...)

I'll either cut the cat out of MP#1 and weld into MP#2
or
I'll get another Magnaflow muffler and weld it into MP#1

How did I accumlate all this crap....

KX500FD1

how about a group buy on the Revo Tune?

FDNewbie

iTrader: (10)

As always, if there is enough interest, I'll be happy to run a GB on 'em

Scrub

iTrader: (25)

Well I have the RE-Amemiya dolphin tail on right now with the Rx-7 store resonated mipipe. I took it to the DMV and it tested at 91 db at 3,500 rpms. So without a resonator I don't think it would make the cut. I have a metallic cat laying around (forget the brand) I was just gonna weld into the midpipe but wasn't sure if I would need air pump connections. Hopefully just the cat with no air pump will be enough to pass mr. emissions sniffer.

-Dan

Ramy,
Thanks for all the great info. Definitely helpful, I'm really likeing that knightsports exhaust and cat, only problem is the cat doesn't have a resonator.

FDNewbie

iTrader: (10)

Dan, I can't remember which one you have (muffler or canister). The regular RE dolphin tail catback is rated for main 80φ and tail 90φ if it's the muffler style, and main 80φ and tail 100φ if it's the canister style (conforming to Japanese safety standards).

Re: the KS exhaust and cat, I can definitely ask them if they offer a cat w/ a resonator, or even if they'll custom make one for me. I actually have a very good friendly relationship w/ Knightsports

~Ramy

Scrub

iTrader: (25)

can't hurt to ask I have the muffler style exhaust.