You're in LA, right? I'm about 2hrs east of you.
Ya, Los Angeles. People may bitch and moan about smog laws but I grew up here when there were smog alerts and days (not many, but there were some) where we kids were told to either not go to school at all or not have recess. Do you understand? So damn smoggy that running around for 10 minutes could screw up your whole day (that irritating cough that won't stop for hours as much as you try to hold it in). There were days when I could go outside and convince myself I lived in Kansas because I couldn't see any of the local mountains
(I live in the San Fernando Valley so there are mountains viewable in every direction) through the haze. I will take the regulations over that garbage any day. And today, with smog regs
, we have stock pony cars putting out 500, 600, 700+ HP. I'm not going to cry about a few cats on my exhaust. This is one of those instances where "the greater good" is actually true.
Sorry, I'm a gearhead and HATE Ralph Nader for what he did to muscle cars (blame the car, not the untrained driver, ruin performance and raise insurance) but I'm in agreement with you can generate power while polluting less. I've lived it, it works.
Anyway, my plan (later down the line) is to just get a set of OEM exhaust manifolds and have them ported instead of getting a set of shorties. My understanding from reading various threads here is that ported OEM manifolds give you better HP than shorty headers. Being in California and all, I'd like my engine to be as "sleeper" as possible. Having ported out OEM manifolds will achieve that objective while also gaining more HP
That may be true and I agree that stock manifolds will be more "sleeper" than any headers with the resulting change in sound, but there's no way that those stock log manifolds flow as good or better than even shorty headers that are designed to minimize blowback into the other cylinders. Now I can believe that the improvement can be so slight that who cares, why pay $$ for basically nothing beyond a more aggressive exhaust note, but log manifolds are the worst. Of course I can also believe that only shorty headers might be worse without improvements in the rest of the exhaust system but my car is aftermarket from the heads back. And for the record I have no annoying drone from the Flowmaster 40s out back (turndowns just past the lip of the bumper bottom).
As for me, I replaced my two primary CATs a few years ago after one of them went bad with Magnaflow High Flow units (CA legal, of course). Even with that little repair / upgrade / mod and the rest of the exhaust system being OEM, it gave it a little bit of "glug glug glug" tone at lower RPMs. I can't wait for the day that I get a full catback system in place. Oh, and I'll be doing an X-Pipe with a set of secondary CATs immediately behind the CAT as my smog guy said that's perfectly CA legal if replacing the stock Y-CAT-pipe.
That's interesting because I've been told that in California (and some other states) you can't change anything
in terms of the cats, not only must you keep the same number of them but there are CARB approved cats with specific part numbers that must be there, so even getting 3 cats in the right places but using the "wrong" ones (flow better) is verboten. You can get CARB approved headers, you can get aftermarket CARB approved cats or cat systems (like the 441111 Magnaflow system I bought with much better tube bends for much better flow). After the cats, nobody cares.
I would actually be on board with wiping out that third cat, replacing it with an X-pipe and then adding 2 more cats after that if it's legal. For-real true dual exhaust. But it's my understanding that I can't. Now that is something that bothers me in this anti-pollution world, that the specific parts are more important than results. I think that if you buy approved cats you should be able to mount them however and wherever so long as the car blows below the max on the various poisonous gasses. But apparently they don't care about that, only about what parts they've been paid off to accept. Nothing's perfect.