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Discussion Starter #1
Lots of new owners these days and I have noticed some confusion on air intakes. First off no one makes a cold air intake for the Solstice, a cold air intake would be somewhere away from the main area under the hood where the engine heat is, on the race version of the Solstice I have seen they popped out a fog light and put it there on the end of a long tube. That would be a cold air intake. What we can get is a custom intake, not a ton of options out there for the GXP, you have GMPP, K&N and Dejon at this point, there may be a few others too. Here is the difference, the GMPP and the K&N are big companies so they make a custom intake that flows about the same as the stock intake so as not to mess up your fuel trims. They have to do this, it's a liability issue, running to lean will possibly damage your engine. They improve flow but not dramatically by design, this is a good thing if you don't have a tuner who can adjust the fuel trims for you.

OK now for those of us who want to increase air flow and do have a tuner available, like Vince from Trifecta or Lyndon from Westers, the Dejon increases air flow by a good bit and it will change the fuel trims to be 5-10 % lean across the band. That is a good thing for me, I just ran a scan and sent it to Lyndon in my case and he adjusted for it. The GMPP and K&N look and sound great but really won't add much in the way of performance, they do most likely supply colder air so that is a benefit. I wanted an intake that changed the fuel trims and I had it adjusted to compensate. Lyndon Wester did some testing a long time ago on the Dejon, as Dejon sent him one for free. It flows more air with the filter that the stock box does with the filter removed, this was done on a flow bench by the way. This is not an ad for Dejon although Dave is a friend, he is just the only example I know of that actually improves flow, his design is very simple by comparison to the others.

Bottom line if you improve flow adjust the tune.
 

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wouldn't removing the plastic "shroud" behind the front grille be close enough to having cold air? I removed the whole plastic piece in front of the radiator so my AEM intake is right behind the grille (just a little above the rear of the grille) and is getting 100% air.

excuse me, I didn't realize this was the GXP thread, could possibly work though for the GXP.
 

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Id like to see a picture of what your talking about DROCK GOT SOL.
 

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This comment has nothing to do with lil goat's discussion of an "improved" intake:

Unless you are a drag racer, you will not really gain anything with a cold air intake, or with modifications to the stock airflow to the intake. I have data-logged the air temperature at the stock intake location and, once you reach about 30 MPH, the temperature there is within 2-3 degrees of ambient and is at ambient once you reach road speed. GM did a pretty good job on the stock system. The temperature at the intake will climb during stop-and-go and when idling, but it drops rapidly once you start moving.
 

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The simple minded sort of buyers seem to think that 'increased intake flow potential' = more power.

I'm sure that sells a lot of product to that sort of person, but to the more discerning, it will be patently obvious that an engine in any given state of tune can only suck so much air. If the maximum air consumption of a particular engine is X, and the intake/filter system on that car flows X+Y, then putting on a system that flows 2X or 10X or 100X does exactly zip for power.

As the Goat pointed out, a lot of after markest systems can screw with your mix, though (I think that the K&N and the GMPP may be the only ones that don't, and certain Fujita intakes apparently actually reduce power).

Frankly, they aren't worth screwing around with unless it is to clean up the engine compartment, or as in my case, to replace the easily broken crappy plastic fitting for a robust version (used on the GMPP system).
 

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Since the stock system stays about the same temperature, would a K&N drop in replacement for the stock paper filter be worth anything?
 

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Since the stock system stays about the same temperature, would a K&N drop in replacement for the stock paper filter be worth anything?
Not in terms of power or filtration (the stock element is apparently pretty good) but in terms of not having to replace it, just wash and oil (lightly - search problems on this), it would be an advantage.
 

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Discussion Starter #8
Not in terms of power or filtration (the stock element is apparently pretty good) but in terms of not having to replace it, just wash and oil (lightly - search problems on this), it would be an advantage.
Like he said.

I believe some modest gains can be made with improved flow as long as the fuel trims are adjusted accordingly, more air means you can add more fuel. GM had to work within EPA guidelines, we don't. That is basically what happens when you get a tune, all the EPA stuff is removed. With the better air flow and the compensated fuel trims my car is certainly smoother at high RPM's, is it faster and does it have more HP, don't really know but I like the way it runs better and isn't that what it's really all about. The big thing is BE CAREFUL when you replace an intake, you can create a lean condition and cause damage.
 

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While this all maybe true with a turbo car, a NA car would be different. I can say with a certain amount of fairness that those that are looking for a CAI for their GXP have probably owned a NA vehicle. I know I have been a Mustang guy for years and a CAI on a Mustang will net you 10-15hp, even though it still gets air from under the hood. An exhaust will get you 10-25 and a HFC will get another 20-40hp....and this is all compounded. A K&N filter with a stock intake will get you better performance on a NA car. My Camaro got almost 3 mpg more with a K&N, and my '08 F150 got almost 3mpg more as well! And my Mustang the difference was enough to be noticable. Now, saying that about NA, I've been out of the turbo cars since '94. And I was young then and don't remember much because "tuning" was still in its infancy stages and I didn't have any $$$ to do it anyway! My GXP has the Fujita, and it pulls air from just above the intercooler, there is no motor heat there. So in saying that, does a CAI on a GXP do anything??? I don't know....but it sure looks cool when you open the hood!!!! :yesnod:
 

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Ghost, my understanding is that there is indeed a small benefit in using an improved intake on a NA. This discussion was only in regard to the GXP, for which the factory did an excellent job making sure the intake wasn't a bottleneck.

BTW, mods aren't often 'compounded' as you indicated, although many young enthusiasts act as if they are, creating a check list of 5 BHP from this mod, 20 from that one etc. and coming up with a supposed total gain far in excess of the truth. In some instances there can be a synergistic effect where you improve flow in one area and it also helps in another, but that's not generally the rule.

Also, be careful about assuming that mileage improvements equate to a GOOD THING. You can get an improvement just be removing an air filter altogether, but that's not what many people are after as it leads to accelerated engine wear.

I wonder which Fujita you have on the GXP. IIRC, one version actually showed a slight decrease in power output, apparently being more, not less restrictive than the stock intake, and the other version had no power loss but did screw with the sensors. We have to be careful about taking manufacturer claims at face value. If we did that, we'd have to believe that sticking a mod on a GXP that showed a temporary power improvement wasn't learned out (they never mention that, do they?) and would disappear in short order so you had zero for your money.
 

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The_Ghost: While this all maybe true with a turbo car, a NA car would be different. I can say with a certain amount of fairness that those that are looking for a CAI for their GXP have probably owned a NA vehicle. I know I have been a Mustang guy for years and a CAI on a Mustang will net you 10-15hp, even though it still gets air from under the hood. .......
Reducing the temperature of the intake air is always a benefit, and can truly gain both power and efficiency. The Kappa will generally not benefit from a CAI, however, because it pretty much came from the factory with one.
 

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Discussion Starter #12
It is a fact that has been proven by DDM that the K&N and the GMPP intakes do not change the fuel trims, that is not an impression. If they don't change the fuel trims the computer is not seeing a change in air flow. They do this like I said so you don't slap it on your car create a lean condition and do damage, could they make a better flowing intake, damn right they could but almost no one does now days. The DEJON, does always has Lyndon Wester showed it on a flow bench and I documented it with HP Tuners on my car, I have before and after scans with no other changes, even driving down the same road when I did the scans. The DEJON showed the fuel trims as 5-10 % leaner, also this was after about 200 miles so the ECM had adapted to the new intake. My gas millage is actually worse, it's dropped almost exactly 1 mpg, makes sense we adjusted the fuel trims to add more fuel to get the fuel trims back to normal. The road I use to test is 12 miles through a National forest, hills and curves all the way, I run between 45 and 90 all the way through, pretty good test track and a helluva lot of fun, I drive it twice everyday.
 

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If an intake results in a change to the fuel trims would that not indicate a problem with its design that is causing incorrect airflow past the MAF sensor ?
 

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While this all maybe true with a turbo car, a NA car would be different. I can say with a certain amount of fairness that those that are looking for a CAI for their GXP have probably owned a NA vehicle. I know I have been a Mustang guy for years and a CAI on a Mustang will net you 10-15hp, even though it still gets air from under the hood. An exhaust will get you 10-25 and a HFC will get another 20-40hp....and this is all compounded. A K&N filter with a stock intake will get you better performance on a NA car. My Camaro got almost 3 mpg more with a K&N, and my '08 F150 got almost 3mpg more as well! And my Mustang the difference was enough to be noticable. Now, saying that about NA, I've been out of the turbo cars since '94. And I was young then and don't remember much because "tuning" was still in its infancy stages and I didn't have any $$$ to do it anyway! My GXP has the Fujita, and it pulls air from just above the intercooler, there is no motor heat there. So in saying that, does a CAI on a GXP do anything??? I don't know....but it sure looks cool when you open the hood!!!! :yesnod:
If you say so. We've been through this on the fullsize bronco forum for years, you gain little to nothing in mileage with K&N and other free flow filters. When I put a K&N in some 14 years ago (drop in) I really didn't notice any change in mileage. To this day I still have that filter, and it works fine, but if it's given me a couple HP out of my 351 I can believe, MPG I'd be surprised if it added even near .5 MPG. I wouldn't use these on the GXP simply because if you are not careful with oiling you're going to have issues. The GMPP intake would be the way to go if I wanted that simply to avoid the oiling and possible sensor issues.

So back to that discussion, I know GMPP still puts the filter forward of the radiator and the fan behind it, so it can still receive cool air when you get going. I think what is more important is that these cone filters placed like this are less restrictive/smoother flowing than stock. Not hugely, but they are. So I can see these giving small HP increases, and it's said the stock airbox removal will also remove 6 lbs of "stuff". I would think that a GMPP tune would be somewhat "adaptive" and could compensate to ensure no lean condition.

When an aftermarket IC is installed such as the Hahn or Dejon, is this also an issue, or are we just talking same flow, but the IC is cooling the air more, making it more dense?
 
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