[shippingguy]

Originally Posted by SS_Don

So if CAI makes the GM one and the GM requires a tune does the CAI require one also?


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No it does not. I asked the lady and she explained something about the tubes internal design. Same exact performance numbers.

[Crushin_LT1]

I imagine the tune is specifically for CARB, tbh.

[ctrlz]

Originally Posted by SomeGeoffGuy

The MAF tube and filter are different on the GM part. So the MAF sensor sees it as completely different, even though they look almost identical. CAI tunes theirs on a flow bench to match the signal from the factory airbox.

Well, this all makes sense.
Would be nice to see photos of the two parts and how they integrate with the MAF. Turning vanes on the Cold Air aftermarket unit would be my guess.

And compliments on nailing the correct form of "theirs."

[SomeGeoffGuy]

I did some digging, and the GM Cold Air Intake is no longer offered - it has been discontinued. I would recommend against buying them used because you can't get the tune. I think that if you could find a kit that was new in the box, that hasn't been installed, you could still get the tune, but that is only speculation.

-Geoff

[VR Baron]

Yeah, it seems they were discontinued from 2021 onward. In kali anyway. When I first started looking at ss 1le’s the dealer I eventually bought from sold different makes, like Porsche, bmw, etc besides Chevy. They were ordering the Camaros with the cai as a option. But said , and as I saw, didn’t on the 2021s onward like my car. As said earlier, tune is a smog tune of sorts, as to pass smog the internal are a bit different and it has the hydrocarbon trap filter like the stock box. So tune is needed. The mystery is if cai tunes their normal intake to the stock box, are smog levels increased or same? If not it’s just to have the carb sticker as aftermarket hasn’t wanted to go through the costs to go through the certification process. HP seems to be 0, rotofab advertising about 10 but at what rpm? Jannetty tested rotofab and got 5 peak. Not worth the high cost imo, unless for sound, throttle response and looks

[SomeGeoffGuy]

Originally Posted by ctrlz

Well, this all makes sense.
Would be nice to see photos of the two parts and how they integrate with the MAF. Turning vanes on the Cold Air aftermarket unit would be my guess.

And compliments on nailing the correct form of "theirs."

There are no vanes in either the GM or CAI part- there is a hydrocarbon absorber (basically a special piece of material similar to a thick paper towel) in the GM MAF tube in order to meet evaporative emissions, and it is close enough to the MAF sensor to effect the flow.

Some background, evaporative emissions are laws that regulate the amount of hydrocarbons (basically gas vapors) that can leak out of the intake after a vehicle is shut off. The material in the tube is supposed to keep the evaporated gasoline from entering the atmosphere by absorbing it, then the next time you run the car, you suck them all back in. Meeting this requirement is the biggest reason that you don't see many CARB legal air intakes - most OEM's put the paper/carbon absorber in the induction system somewhere.

With flow benches, it is relatively easy for an aftermarket air intake manufacturer to match the OEM MAF transfer function for an intake and make it "no tune required". Some aftermarket companies are better at this than others, too, and some are in fact really BAD at this (you can tell the bad ones because they start throwing codes). It is virtually impossible, though, for an aftermarket company to meet evaporative emissions. The testing is just too expensive, and needs to be proven at both the vehicle and component level.

-Geoff

[SomeGeoffGuy]

Originally Posted by VR Baron

As said earlier, tune is a smog tune of sorts, as to pass smog the internal are a bit different and it has the hydrocarbon trap filter like the stock box. So tune is needed. The mystery is if cai tunes their normal intake to the stock box, are smog levels increased or same? If not it’s just to have the carb sticker as aftermarket hasn’t wanted to go through the costs to go through the certification process.

From an emissions standpoint, the CAI part (and rotofab, k&n, etc...) doesn't meet emissions requirements strictly because it doesn't' have an absorber. It might still pass all the tests without the absorber, but by not having it, it is automatically out of compliance. From an exhaust emissions, it should perform identical to OEM (assuming that the transfer function is within 1% or so). So you should easily pass a sniffer, but per the letter of the law it is out of compliance.

-Geoff

[SS_Don]

Is this for all states or just the ones like California?


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[VR Baron]

Originally Posted by SomeGeoffGuy

From an emissions standpoint, the CAI part (and rotofab, k&n, etc...) doesn't meet emissions requirements strictly because it doesn't' have an absorber. It might still pass all the tests without the absorber, but by not having it, it is automatically out of compliance. From an exhaust emissions, it should perform identical to OEM (assuming that the transfer function is within 1% or so). So you should easily pass a sniffer, but per the letter of the law it is out of compliance.

-Geoff

Yep. Same with fourth and fifth gen cars. No carbon trap and no carb cert. nothing new, but was cool Chevy actually offered it and went to the trouble. For awhile anyway.

[SomeGeoffGuy]

Originally Posted by SS_Don

Is this for all states or just the ones like California?


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It's completely discontinued everywhere for everyone. The emissions requirement is also Federal, not CARB specific. So applies to everyone too. Not sure which one you were referring to, but both are for everyone.

-Geoff

[ctrlz]

Originally Posted by SomeGeoffGuy

there is a hydrocarbon absorber (basically a special piece of material similar to a thick paper towel) in the GM MAF tube in order to meet evaporative emissions, and it is close enough to the MAF sensor to affect the flow.

So I guess this is thin charcoal-impregnated media that covers the whole cross section, otherwise it would be kinda stupid.
And I suspect the stock intake has a charcoal layer incorporated somewhere on the stock air filter. The residual intake HC's should be pretty low, so I don't think you need much media to adsorb them.

These evaporative emissions statistics are somewhat insane. Supposedly you would vent about an ounce of gas to the atmosphere while filling an empty tank with no vapor capture device in place. And if every car in the US was like this, we would release enough fuel to power 300,000 cars for a full year. That's just the US.

[Sephx1]

Interesting thread. I bought one for my 2021 SS 1LE last year and had the dealer add the tune. On the service ticket it says that the modified tune is in GM’s global system under my VIN so any reflashes to the ECU will include the tune for the intake.

[Twizzty]

Still can't find one of these CAI for my 21, started looking late last year and no joy. Spoke to the dealer and a few other contacts and they say GM currently won't release it after being built as the dealers aren't doing the tunes like they're supposed to. I don't know if this is correct but it's what they're all saying.

[SS_Don]

I too have been unable to find it. I will go with the Cold Air Inductions one when I am ready to purchase.


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