MrDomino

iTrader: (3)

I've been looking around for quite a bit, and have finally decided what I want to do with my exhaust. Now, I have to worry about the CA smog *****, though, so I was hoping you guys could help me out with it.

1. I read in a post here that dumping before the axle was actually not illegal, as long as they were dumped a couple inches away from the fuel lines, etc. He said that the documentation was buried in the dmv website somewhere. I looked for quite awhile, but to no avail. Could anyone help enlighten me?

2. Is it possible to do a true dual, x pipe setup that bolts to the stock cats? What are the costs involved?

I plan on getting some of the edelbrock shorties (or TES, to be official), and would like to run that through the stock cats, to a fabbed x-pipe, through a pair of Sweet Thunder chambered mufflers, then dumped before the axle. Is this possible?

Someone posted this videoclip of the Sweet Thunders making a whooshing sound: http://www.ls1poweredta.com/videos/s...underincar.wmv . Contrary to the other peoples' opinions, I actually really like that sound. Almost sounds like a turbo, to me. It's quite appealing. Would my planned setup sound similar? That particular video is through the stock manifolds and y, then through a loudmouth with the Sweet Thunder in place of the resonator.

Thanks to anyone who helps. I know it must seem like I'm lazy and don't want to do my research, but I've been searching for quite awhile, but finally decided to ask you guys for help, since I couldn't find what I needed.

Redneck Z

iTrader: (3)

1st off CA sucks! Technically none of your plans are legal. You need to maintain the stock exhaust configuration(IOW single exhaust). If your exhaust comes out the back in stock form, then it has to stay that way technically. You can basically run a CARB legal shorty and good catback for 100% legality, or say screw it, run longtubes and go somewhere that won't fail you on the visual. This whole CA visual thing is STUPID anyways. All that should matter is that your car passes the sniffer!

jrp

iTrader: (16)

go shorties and bassini true duals

Redneck Z

iTrader: (3)

Dual exhaust is not legal though.

MrDomino

iTrader: (3)

Well, I guess I can live without true duals =/. I *really* wanted the extra 'oomph' from the X pipe, though. Not to mention, I love turndowns dumped before the axle. I hate CA . Did you know that gas prices are going down like, $0.50 in every state except CA?

Anyway, what about the shorties, to the stock cats, to a TSP Rumbler with a Sweet Thunder muffler welded in the I pipe, and the dynomax bullet removed? Does anyone have any idea the gains I'll see? Right now I have the stock system, with a flowmaster muffler welded in place of the stock one. Came that way, with the car.

Is there a california legal replacement Y pipe? The stock one is so flat, I couldn't see that being good for flow. Are they included in catbacks?

Redneck Z

iTrader: (3)

If you want a good, basically legal shorty header setup, you could do something similar to what I did. JBA shorties into a SLP replacement pipe, with magnaflow OBDII compliant high flow cats, a flowmaster y merge collector and a magnaflow catback. I'd think that's about all you can really do to maximize a CA setup. I ran that setup until I finally decided I couldn't live without longtubes anymore lol.

LS1Bandit

What about it is not legal? When I talked to the CA bureau of automotive repair and also to the smog referee (I'm working on a conversion, so need to make sure I'm going to pass), they indicated that you can do whatever you want after the cats.

As far as I have been able to determine, running a true dual after the stock cat pipes is perfectly legal.

Am I missing something?

Redneck Z

iTrader: (3)

I think it depends on who you talk to. I have spoken to a ref as well. Not only that, but I believe it even says on the CARB website that you need to maintain the stock exhaust configuration. In otherwords no single to dual conversions. I also knew a guy with an LS1 conversion that tried to run duals, and was told by the ref to change it to a single, because the original car the LS1 came out of had a single setup from the factory.

ps. Is the car you are converting a 75 or older car?

LS1Bandit

Well, I've read almost every site out there and I've also tried deciphering the actual text of the law. Best I can tell, and this is also what the BAR and ref guys told me was that everything after the cats is OK.

But I guess if there's any question you (the person asking the original question) should talk to them directly.

I know I'm going to do a full dual-exhaust and I'm going to have the smog referee look at it when I'm done.

Unfortunately no, it's a '78 T/A. And thanks to the Governator, my car will always have to pass smog. Before the most recent legislation I'd be smog-exempt in 2 years.

MrDomino

iTrader: (3)

No, it's a 99 Z28. Daily driver, that's why no cam, heads, or longtubes =]. Plain and simple, I just can't afford that setup that you recommended to me, too expensive. I think I've prettymuch made up my mind to weld a Sweet Thunder into a Rumbler, I just wanted to make sure it was legal. It appears that it is, since it's after the cats. Now, I'm just kind of curious what gains I could expect from it.

The thing is, the sound of my exhaust is really important to me. The clip I posted is just about perfect sounding, including the whooshing. I really like the sound of chambered mufflers, but I can't afford to drop the dough for GMMG.

So, my two, hopefully final questions are this: what kind of gains might I expect? And, I know that whooshing sound I like is indeed restriction, but how much do I really stand to lose from it?

Thanks.