alex5366

Whats up fellas, quick question. I have a bone stock z28 1996 m6. I have plans on to making it push at least 370-400 hp without gogo juice nor supercharger. The thing is that I live in California were the law is b@#$. So I want to know what can I do to my exhaust system as I must have cats. My plans are, pacesetter LT's, CAI, ORY, Hooker cat back and maybe some dyno max 3" rolled tips.I was also looking into the cc03 cam but would I need any other things to accommodate it? Any help is gladly appreciated and suggestions on what I should install.

Injuneer

You're in the wrong forum... LT1 Z28 does not qualify for "V6 Tech" forum

I'll move your post to "LT1 Based Engine Tech".

You can't do anything to the exhaust system that alters the location of the stock cats, changes the number of cats, and you can't replace the cats unless they are determined to be defective (Federal law, enforced in CA). That means you can't use long tubes, since they move the cats. Only headers you can use are those certified by the California Air Resources Board (CARB) and having a CARB-EO certification tag welded to the #1 primary. Most people who were making CARB-EO certified cats seem to have stopped making them.

You would have to have a Y-pipe with the cats in the stock location (not an off-road Y), and you have to keep two cats (not a catback with a single cat). You have to keep the two after-cat O2 sensors, one for each bank of the engine.

Probably ways around this, but we can't give out illegal advice.

Chimera96

OP

Fred pretty much sums it up. Now especially since the STAR smog test went into effect here in Calif. the "$300+" pass my car places are not really around anymore. Their license will be pulled and they will be heavily fined. CARB even has sting cars they take at random (or to places they suspect) doing illegal smog test certs.

Header manufacturers have to pay big $ to get a CARB certification and those headers need to preserve the stock location for CATS.

Muffler shops just rape you now on installing OBD2 CARB certified CATS...like to the tune of $400+ each. MagnaFlo does make OBD2 CARB CATS though

doing a H/C 383 with shorty CARB headers is very doable with the right cam selection AND tune and pass "test only smog testing"

FYI on a CARB certified header the "model #" will be on a plate welded to the header AND a CARB sticker identifying that model # to the correct exempt certification. You need the sticker also so if buying used headers...contact whoever made them and see if they will get you another sticker

MachinistOne

The easiest way is with either cubic inches, or forced cubic inches(blower).

If a complete engine build is not in the cards, you're limited to the CARB certified shorty headers on the market + a head and cam setup with a wide lobe center to limit overlap and keep motor efficient at low rpms where the sniffer test takes place.

High flow cats can be put in and nobody can fault you for it considering how old the vehicle is, and the plausibility that your oem cats are in fact, bad. I've used the Magnaflow cats on my own vehicles and they do pass the sniff test, but they are extremly fragile and I broke two of them just barely tapping a speed bump while creeping over it on two separate occasions. I switched to metallic high flow cats which are indestructible, but they failed to pass the sniff test.

If you get friendly with a speed shop there's still ways around the letter of the law....

Chimera96

....well while there may be ways to circumvent "legal" compliance I can't advise on those possibilities.

I can say, living in Calif and getting "STAR" test only smog notices stating my vehicle is in a "high emitter" profile, you have to play by the book.

If you have "non OEM CATS" they need to have a CARB compliance certification. MagnaFlo does carry a "CARB" certified line but it is twice what (sometimes more) than non CARB CAT would be.

To add insult to injury the STAR test tech can and does look to confirm the installed CAT is in fact CARB certified. OBD2 is even another level.

Can you find a shop less "critical" on passing the car...maybe.

The irony is the tail pipe sniff passes with flying colors. Visual and CARB compliance rule above anything in Calif. Your car can fing make pure oxygen but if it does not pass "visual" because the CAT you have is a $69 Catco generic replacement non CARB approved..it will fail. Regardless if it spits out pure oxygen out the tail pipe.

97WS6SCharged

Figure out a way to register the car in Nevada.

Chimera96

there are ways to circumvent smog compliance. You would have to make those choices yourself and understand that in doing so may have consequences.

registering a car out of state for example may get you around smog compliance where you actually live

a downside however, nothing to do with smog, is if you claim false residency to your insurance company and then file a claim due to a accident, especially if you are at fault, understand the 1st actions any insurance company takes is to see if they can get out of the claim by identifying false reporting to secure the policy. They can deny coverage, and insurance policy, in the case of claiming residency falsely.

since the other party's insurance can not make a claim against your, then denied coverage policy, rest assured that insurance company will go after you

so, IMHO, think about it.

Would I like to run LT headers, yes. For me though just not worth the dance to get that extra 10-15 HP over the shorty CARB headers and CATS

Injuneer

And there is very little loss of performance with cats, and no performance loss with EGR or AIR. Deleting this stuff is way overblown. It isn't worth it.

cheapchevy

Just CA smogged my 96 Z28. Failed NO by 3 ppm. So I installed Magnaflow drivers side cat for $300 and all emissions dropped in half. Its all legal now.

One option, install shorty headers that will bolt onto stock exhaust. Then every two years, one can install stock cats for smog test. After passing, one can bolt on Random Technology high flow cats and y-pipe. No loss of power with Random Tech - but only 49 state legal. More power, sounds better.

alex5366

how can i get those cats in L.A? ive tried ordering from man places bu wont ship here since only 49 sate legal

alex5366

Is it possible to install Pacesetter LT's, with Stock Cats, hooker/bbk/kooks y-pipe, hooker/flowmaster catback? Or do you kow of any other setup that would sound aggressive and slightly choppy? I also have future plans to install a cc503 cam (i think thats the name of it).

Chimera96

well you are now seeing how hard it is to buy non CARB certified CATS in Calif.

you will have to find what post # 4 suggests to try getting LT's with bullet CATS like the Random Tech ones installed. If you do you will certainly fail visual on a smog test. The bullet CATS may not pass tailpipe anyway

Injuneer

No. The long tubes would move the cats (which have two different shapes and connections, left and right). Moving the cats is not legal, under Federal law. As far as I know, CA strictly enforces Federal law. LT's cannot have a CARB-EO certification, so that's an additional problem.

The only way around it would appear to be swapping the stock exhaust system back in every couple for your smog check. And hope no one pulls you over and does a visual in between, noting that you have an illegal exhaust system.