That really says very little as I and others have passed sniffer tests without a cat. Passing a sniffer is pretty easy and can be done with just a tune geared towards reducing emissions. Passing an OBD-II test takes a O2 CEL eliminator, no cat or tuning involved.

I would like to see some numbers to back up that these high flow cats clean the exhaust as well as the stocker, or even just perform at least some what similar to a normal cat.

To spend money to clean the emissions up is a good idea. But if they really don't do anything for emissions, then it's just a waste of money and is dropping power for nothing.

 

a few random points.*

but first my recent problem, I had loose turbo bolts which lead to my gasket burning away(?). Couldn't find a reason for my low boost and figured I had wasted another turbo somehow. Happened to check the perrin hfc and saw that the cat had been dislodged, maybe from a piece of gasket? Anyway that little bit of misalignment lost me 8 psi boost. Put in a test pipe and the car is a winner again.


* I had to do an obd2 test this last winter to get a license renewal here in WA state.
I had the perrin hfc and an extension on the 2nd narrowband. Passed no problem.
(normal closed loop function)

When I replaced the hfc with the test pipe I figured I'd have a cel, no, although I can't say why. It could be two things.
1, the anti fouler on the narrowband.
2, my ecu runs in open loop full time now. since my fuel trims are never touched by the ecu I am thinking the first and second narrowbands are "out to lunch".
guess I could take off the fouler but I don't want to touch a thing. knock on wood.

I've pmed about getting the 100 cat when it is "bolt on". Although my tune is over lean it still has the faint fragrance of gas in the garage.

But mostly I'm a happy guy because my car doesn't need a new turbo.

 

Couple of things...I am not really in the habit of selling "snake oil," so take that for what it's worth.

If you mess with a tune to pass a sniffer test, that's really kind of missing the point, don't you think?

Here's another kind of sniffer test for you...your nose. Anyone can tell the difference between a test pipe and a catted exhaust. Test pipes smell like crap. I just got out of a dyno room with a car running a testpipe. Now I have a headache. That doesn't happen with my car, so the cat is doing something. Maybe it's the PGM coatings.

Besides the 100 cell cat, I also have 200 cell cats with EPA certifications for 48 states. I guess that should mean something, no? I choose to sell the 100 cell to the Evo community because they value horsepower. The 200 cells are for Porsche owners, who don't want idiot lights coming on in their $130,000 vehicle. The new 997TT runs a wideband 02, not a narrowband so they are very touchy.

I don't think anyone (at least myself) has claimed the metal substrate cats clean as well as OEM. The point has always been they clean the exhaust AND provide great flow.

 

My statements aren't directed at you in particular but high flow cat retailers in general.

Instead of subjective judgments, I'm just asking for some numbers. Getting a car on a chassis dyno with an EGA wouldn't be terribly difficult.

 

All of the smog test places in Cali only have 2WD dynos. AWD cars just have stationary tests. Mind you, I am all for testing. At some point I aim to do that. I will say, my nose says there's a BIG difference.

 

Well for this particular cat (Apexi Super Catalyzer) if you go to the Japan Apexi site (http://www.apexi.co.jp/products/exhaust/super_cata.html) you will see how they tested and made this cat. They make it based off a special machine used to measure diesel smoke emissions for commercial use. Apexi then made this cat at 130cpsi but being how its internals are rare metals (platinum I believe) and the longer body it actually puts out better emissions than the stock cat but flows about as good as you can get. Their website shows emissions testing done on this car plus the oem evo one and this one produced less emissions. Mil Spec with no doubt flow better but it wont be as emissions friendly as this one. It will definately help over a testpipe but most likely is some strict states wont pass the sniffer test.

One thing I find odd was I know of one person that only gained 5whp 3wtq on an FPGreen going from this hfc cat to a testpipe. I guess all setups are different I just expected less of a hp difference.

 

What kind of cat? I know one person who gained 14whp/14tq on a Mustang going from a ceramic 3" HFC to one of our 100 cell units.

 

I meant the Apexi unit. He only gained 5whp switching to a testpipe from the Apexi unit on a FPGreen. I believe it was on an VIII though.

 

THat's interesting considering that Bryan showed a 16whp peak loss with the Apex'i vs. testpipe and 20+whp loss at 6500+ rpms in this thread.

 

Thats why I thought it was interesting. 16whp is more than I expected. I guess stock turbo maxed out is more touchy to restiction possibly?

 

I think that a stock turbo maxed out just exemplifies the amount of back pressure that the Apexi unit creates. Think about it, more flow = more power. Well the car on the dyno has most everything upgraded as far as flow is concerned. So a car with "less mods" will show less of a drop because their are still other areas that need to be upgraded for flow. Not sure if this makes sense?