fabric

I have an 87 with California emissions. So while it's probably got reasonable emissions, I imagine they are not as good as current cars. Are new, high flow cats (such as Random Tech), probably higher performance *and* better with emissions than what I have now?

I'm not trying to pacify any internal need to "be clean" here. My car get's 15 mpg. But it might help rationlize to myself that I need to make a "performance" upgrade, and maybe make up just a little bit for the economy figure. Thoughts?

worf928

All other things equal a new cat will likely be cleaner than an 18 year-old cat.

Jim Nowak

This one is a better deal than the Random Tech. It's stainless exterior with metal substrate for extra high flow. http://www.jegs.com/cgi-bin/ncommerc...34&prmenbr=361

Mongo

Dynatech's catalytic convertors to my knowledge are not street legal. There is a huge note in the Jeg's catalog saying that they aren't CARB legal. Maybe they didn't wanna pay the vast amount of $$$ to have CARB test and certify the cat?

mspiegle

I was actually speaking to my smog/muffler guy the other day about my BMW which i'm trying to get to pass smog (might just install the SMT6 on it and lean it out).

Anyways... factory cats are VERY good at reducing emissions... at the expense of some flow obviously.

He actually said that the particular cat on my BMW ('87 325is) is pretty sizeable and filters an awful lot. If you were to compare and unused stock cat for my car against the latest and greatest aftermarket cats, there would be very few if any that could filter better (but most would flow better).

So, in short... cat technology today hasn't changed much from the late 80s with respect to filtering. Sure, they're freeer flowing, but most freeflow units can't filter as much as the stock units could. He said that he garuntees i will fail smog with any of his 'free flow' cats and that I would need the BigAssMofo cat if I wanted to pass. I trust the guy's opinion... i've never sensed any BS from him.

lorenolson888

That is interesting mike... Has anyone out there passed smog with a modified header and cat setup??? I know that one could get some fat ones (two 3" to a sigle 3.5" from devek but I am not sure if it was meant for street use... I think that with smog no one really cares if the CARB # is on... They have never inspected any of my cars.. just quick and dirty sniff test the gas cap seal and give me my cert...

Nicole

There is a company in Germany (www.landsharks.de) that offers an emissions upgrade kit for the 928 S4 and later models. It takes the car to the next lower level of emissions class (Euro 2), and brings the owner a registration fee/tax credit as well as lower future registration fees that pay for the upgrade over time.

Best of all, the package includes at least 40 extra horse power.

So how do they do this?

The solution consists of modified stock cats that now contain free flowing metal instead of ceramic cat material. In addition they custom program a chip for each car on the dyno to achieve the balance of the lower emissions and the higher output.

As side effects, owners have reported a throatier sound, and lower fuel consumption.

Sounds too good to be true, but there are quite a few such testimonials on the German Porsche Fan Forum (www.pff-online.de).

Total cost in Germany, including labor, is Euro 2,300 - about $3k.

FlyingDog

Is CARB just CA or is that a national certification?

Also, how do Magnaflow cats compare to Dynatech and Random Tech?

Bill Ball

Loren:

Where do you go for smog testing?

fabric

Clearly a bit more research is needed. I'm not in any hurry to do this, but I may see what I can find out. I guess I was wondering how much cleaner were the CA emissions in 87 than rest of US.

bd0nalds0n

Steve Pappin started a thread about having difficulty passing CA smog and detailed his experiences with Random Tech cats. IIRC, Steve had to disconnect the air pump (or route it "nowhere") b/c the extra air was cooling the cats down too much to be effective. Once he got rid of the extra air, I think his car passed with flying colors.

mspiegle

I think with the 928s, we might have some extra headroom because they run so damn clean anyways. But yes, Steve Pappin did pass smog with flying colors using an x-pipe and random tech cats. As long as everything is up-to-snuff, it probably isn't a big deal.

I used my BMW in my example above... probably doesn't run as clean as a 928.