[clg82]

Hey everyone, just like the title says! I have a mainly stock 2020 zl1 that I’d like to start modifying but with all of this smog issues i don’t know where to start. What modifications do you suggest starting out with while staying smog compliant. I mostly use my car on the weekend at willow springs or some straight line stuff as well. Thanks for any help!

[Evansa22]

Their aren't many options to stay CARB compliant.
I believe the 2650 magnuson has a pending approval. Might be your best bet to stay legal and make some good amount of power

[ThirstyDave]

Just look for a smog hook up and so you don't have to worry about being smog compliant

[clg82]

Originally Posted by Evansa22

Their aren't many options to stay CARB compliant.
I believe the 2650 magnuson has a pending approval. Might be your best bet to stay legal and make some good amount of power

I have been keeping my eye on that particular supercharger but i'm unsure how long it takes to get CARB stuff approved here. Is there a 6 month wait until we can see these for california? 6 years? in the meantime i'd like to upgrade what i have now without having to worry about not being able to smog. When it comes to the 2650 what types of gains do you foresee over stock?

[clg82]

Originally Posted by ThirstyDave

Just look for a smog hook up and so you don't have to worry about being smog compliant

i wish it was that easy.

[beemer105]

CARB Testing can be anywhere from 6 months - 3+ years.

Crappy part can be that it can also be very model specific.

I have no doubt that COVID affected the speed of testing as well

[kropscamaro16]

nothing is carb legal for these cars other than the gm intake


afe mishimoto kn rotofab etc... they either dont care or cant do it anymore

[90503]

Put your money into tires and wheels, brakes and brake pads, track fluids, etc....I wouldn't touch anything under the hood or exhaust. You don't have to wait for a smog inspection for trouble....Any traffic stop could look for smog modifications and violations...Good luck.

[Evansa22]

Originally Posted by clg82

I have been keeping my eye on that particular supercharger but i'm unsure how long it takes to get CARB stuff approved here. Is there a 6 month wait until we can see these for california? 6 years? in the meantime i'd like to upgrade what i have now without having to worry about not being able to smog. When it comes to the 2650 what types of gains do you foresee over stock?

Not really sure, maybe 60-80whp. I've read they have to really dial back the tune to be carb compliant, or for a chance to be compliant anyways.

Now if your not worried about being smog legal, you can up the boost, custom tune, and probably hit over 100 whp without too much effort. Just my guess

[clg82]

So looks like there isn't many suggestions for me in here, would a lower pulley/e85/tune be a good starting point. They don't use the sniffer in cali on these new cars and it's straight OBDII readers so I think I could get away with those modifications for now....maybe even port and polish the supercharger? Thoughts?

[Evansa22]

You have an end goal? Or just looking for a little more power?
Lower, e85, port and polish supercharger, and tune sounds like a good way to go and stay stealth smog wise. I've seen ppl recommend at least headers to deal with the extra heat from the lower pulley however. Disclaimer, I'm no expert, just passing along what I've read here on the forums

[clg82]

Originally Posted by Evansa22

You have an end goal? Or just looking for a little more power?
Lower, e85, port and polish supercharger, and tune sounds like a good way to go and stay stealth smog wise. I've seen ppl recommend at least headers to deal with the extra heat from the lower pulley however. Disclaimer, I'm no expert, just passing along what I've read here on the forums

Just looking for a little more power, are cooling mods required when doing lower pulley? And what ones would everyone suggest. Also are headers mandatory when going with a lower pulley swap?

[Evansa22]

Don't think they're required, probably a good idea. Depends what your using the car for. Cruising around and backroad runs i would think you'd be fine, road coursing it might cause issues. Many like the c & r heat exchangers if you swap. Don't know that headers are mandatory but probably a good idea.

[SoCal Racer]

Originally Posted by clg82

So looks like there isn't many suggestions for me in here, would a lower pulley/e85/tune be a good starting point. They don't use the sniffer in cali on these new cars and it's straight OBDII readers so I think I could get away with those modifications for now....maybe even port and polish the supercharger? Thoughts?

In CA, if you want to stay legal...either you buy the fastest new car you can afford...or you buy an old car that is CA exempt and modify it like crazy. Those are pretty much your "legal" speed options...

Every person on earth is different and people's thoughts and boundaries when it comes to the Law are different...everything from by the book....to I don't care ...and everyone in between. If you live in CA we have the strictest emission Laws in the nation...that is why many vehicles would be labeled 49 state legal...where is it not legal? yep, right here lol. Other states laugh at us and rightfully so, but we do have sunshine 95% of the year and beautiful beaches all along the coast, so ha. Only each person can answer how far are you willing to go for speed, while "bending" the law. The Police do not have time to go looking for your aftermarket headers or high powered supercharger...they are usually going to get you when you do something else wrong...like speeding, or crossing a red light....rolling through a stop sign...exhibition of speed in a school zone or in front of a Police cruiser...oops.

If you are worried about smog checks, your car is listed as a 2020, so you have 3-4 years (depending on when you bought it) to worry about it. No smog checks until then...if you put on minor bolt ons, you can always go back to stock for your smog check when you are due....then put it back after you pass your check, then you are good for another two years That is how you see all of these modified cars rolling around SoCal...unless you "have a guy" Unless you are doing a massive motor build which would be hard to undo for a smog check, I wouldn't worry so much. Just enjoy your car and don't break the basic laws to avoid the Police all together...they love Muscle cars, most of them drive one. I have alot of Government and Law officers in my family and circle of friends...most have some kind of muscle...they just go after the German cars and noisy Hondas