I had a CAI on my GXP and was an interested observer when there were a LOT of threads discussing the utility of a CAI.
The end result was
1) GM powertrain engineers made it clear that the factory filter was very efficient and not a limiting factor on HP
2) Several people with tuned cars noted that the CAI did not provide any measurable improvement in performance
3) The CAI is not truely a CAI as they all take in air from the same location as the factory airbox
4) One member ran tests and found that once the car is in motion, the temperature at the intake for either the CAI or the factory airbox is essentially ambient temperature
5) All CAIs eliminate the sound trapping design provided by the factory airbox and as a result you get a lot of intake noise that some find disturbing
6) Some CAIs were found to actually reduce performance
7) Several members noted that using an oiled aircleaner element resulted in MAF contamination. This elicited a lot of discussion.
The consensus opinion I came away with was that I would not use an oiled filter element, that the CAI isnt, that there is little or perhaps no improvement in performance and I can testify to a lot of intake noise.
Just to revive this and get it back to K&N CAI.....
Where did anyone find this? If you go out to K&N's site, there is no CAI offered for the 2.0 Solstice/Sky (I know Rob that you are using dejon)?
So with Rob's comments above, items 1-2, look at the dimensions of the stock flat filter, .875 thickness (this is a bit thinner than many other filters I looked at tonight), 14.75" x 9.5" this is HUGE (this is from K&N's site)! Just look at the square inches, go and put in any vehicle on K&N's site and look at filter size. Not that I am complaining but why is the filter so large?
I looked at the following vehicles just to see what was going on around the auto world:
'09 Corvette, Cobalt, and HHR (latter 2 turbo)
'09 Mustang shelby
Nissan 370 (has dual filters)
K&N has flow data for their replacement drop in filters. The Solstice GXP filter is shown to flow 943.6 CFM
. The 2.4 for that matter with almost the same filter flows 842.2. Both are also shown to be very efficient in allowing dust clogging while still flowing.
What's amazing though is that no other filter came close (filter not as big):
The Ford v10: 783.7 CFM
Cady ctsv: 428
HHR: 176.3 CFM !!!
With respect to item 3 above, not sure about that. From what I have seen the aftermarket CAI's that are available do take air from in front of the radiator like the stock air box, but that's all I would say. The stock box takes air from the very front of the car right at the air intake honeycomb to the right of the license plate (and just a little above). So this would be more of a cold air intake, and as shown above in comparing with other vehicles, don't worry about CFM flow.
Item 7 and MAF, I have always been very concerned with this, but if you read K&N's site, they provide several tests where they seem to be very certain their oil is NOT causing any MAF issues.
I wouldn't mind trying the K&N drop in filter after reading on their site, but I'm not sure this would improve performance much over the stock filter? Do we really need more flow?
K&N does list CAI's for the Cobalt and HHR, but no wonder given their stock flow. Interesting though, they show like 10HP or so increases, yet aren't we all supposed to be rated 260HP from GM? Makes me wonder on fudging numbers here with GM, ie give or take 10hp we're going to list all these 2.0 lnf's as 260hp stock. Reality is the potential is greater with the Solstice/Sky in terms of intake air flow and power output?
just some thoughts/observations.... Can anyone find a K&N filter on their site with higher CFM flow numbers for a stock drop in element?
'09 Solstice GXP Coupe #492, Mysterious, Auto, 6567 miles.
DDM Venom Brace
DDM 3/8 Performance backbone
DDM Catch can, Tclamps and fender trim kit.
GM Accessories incl. race pedals, rocker panel clear protective tape, console storage bag, and soft targa top.
'95 Bronco, owned 20yrs, totally custom on 37's, my DD
'11 Subaru Forrester, wifes DD.