Ok, I know this has been asked several times but what air intake systems should I be looking at? I have a just purchased a 2008 Corvette, Automatic, Dual mode exhaust.

 

There is nothing wrong with the stock LS3 intake. It is the same as the Z06 LS7 intake and uses the same filter element. Some of the aftermarket units will cause surging, or possible problems with scooping water or elevated coolant temps. Some will tell you to do a tune to fix the surging problems, others will tell you to tune to maximize the effects of the aftermarket intake. Just realize that putting a tune in your car can cause you to lose your GM warranty.

From my observations, you get a slight horsepower increase from an aftermarket intake(can you really feel 10-12 horsepower in your butt on the street), but most of the advertised big HP increases come from a tune. Of course, you could also just do a tune without the aftermarket intake and see an increase in horsepower as the factory settings are on the rich side and conservative.

 

I'm with Joe. You have a good intake.

Larry

 

I'm with the others why mess with something that is just as good as what you are going to get.

Now if you were going to change the headers, X-Pipe, and stock exhaust, I would say to change the intake also. Most don't realize that you have to get out what you are putting in and if you change something on the front-end and nothing on the back-end there are no real gains.

Me myself I went with Kooks headers and X-Pipe with SLP exhaust and Callaway Honker up front. Now having CarTek tune the car since I moved the cats and sensor's futher away, then it will be a cam, rods, springs and fast intake for completion (and another tune).

 

Joe is exactly right.

 

with the above posts. Stand alone an aftermarket intake is not worth the money. If you plan on doing some mods i.e., headers, cam, and of course a tune. then yes!

The LS3 air intake is a very good intake, except it needs cold air. At idle and low speeds, engine heat can get into the intake. Once air intake temp reaches 86 degrees, the ECM will start to pull back timing which will effect horsepower. I modified Halltech's "Beehive Shroud" to fit the LS3 intake and cut two open ports at the bottom of the shroud for cold air. This method is described on "Halltech"s website." The end result is cold air feeding the stock intake which will preserve horsepower and warranty safe.

 

I had Stainless Works Headers and Hi-Flow Cats, Callaway Honker installed along with a Dyno Tune - 418 rwhp - 2008 A6.

 

Cutting two slots at the extreme ends of the shroud is okay, but do not cut any openings in the center of the shroud where air will be directed directly into the mouth of the breather. This can cause turbulence at the MAF causing all kinds of problems.

If you look below the two crash impact sensors that are bolted on the frame bumper beam you will see small openings into the area behind the grill, This lets cooler air into the airbox compartment without disturbing the airflow into the air breather. Also, farther out you will see much larger openings where you can view the ground next to the frame rails. This lets air into the airbox compartment from just in front of the air dam, next to the openings for the front brake ducts. If you have a GS, then additional air is furnished to the airbox compartment through the small duct in the top of the front bumper cover. That air is not ducted directly into the airbox compartment, but is diffused so as to not create turbulence to the MAF.

I installed a Vette-Air scoop behind the grille about 5" in front of the radiator. It was necessary for me to install a diffuser that I made out of 1/8" Plexiglas to cover the discharge opening of the scoop as it was blasting the air into the filter at 70 MPH and driving the MAF nuts, throwing all kinds of codes/CEL. The diffuser is sealed to the bumper beam at the front and is bolted tight to the scoop at the rear so that 100% of the air is directed away from the air filter's opening. I'm now getting a nice blanket of cool air(especially at speed) completely surrounding the air breather, but not directed directly into the mouth of the breather. I'm using the stock GM Donaldson air filter element. I tried the cotton gauze Attack Blue filter in the stock breather, but it did a poor job of straightening out the air flow and was causing the MAF to go crazy when combined with the Vette-Air scoop before I installed the diffuser.

After all that work, and expense, to install the Vette-Air scoop and then designing and installing the diffuser(several times, until I got the design that worked 100% of the time) I doubt if I gained much over the stock shroud openings in my Z06. If I were to do it again, I would just install some small scoops at the two openings in the shroud under the crash imact sensors, to help them scoop a little additional cold air from the grille opening into the airbox compartment.

 

I have a hand diagnostic/tuner/reader and I have logged intake temps on my current car (370Z) and at idle the tmps were very high above ambient temps but when the car was moving the temps very quicky dropped to just 7-8 degrees over ambient temps. Im sure the vettes intake will be the same. So stock intake while the car is moving is doing very well and wont change timing very much if at all so all that rerouting of shrouds etc may not really help any. They probably wont hurt either if they dont cause turbulance but that usually gets cleaned up in the intake. Now like someone said earlier if you open the front up you need to open the rear up and visa versa. But Im not sure how much the stock intake flows at WOT and how much air the car actually pulls at WOT. If the car doesnt pull more than the filter can flow then no need to change it.

 

The LS3 intake is the same as the Z06 and the ZR1, except the Z06 housing doesn't have the silencer and the ZR1 is molded slightly different because of the supercharger. The factory air filter element is the same on the LS3 and the LS7, and the ZR1 is the same design but flows better. Some have used the ZR1 filter element in their Z06 and LS3 breathers. If the GM design air intake can flow enough air to support the 638 HP ZR1 and the 505 HP Z06, it will flow enough to support the 436 HP LS3.

 

The opinions and some statements about air temperature differences between air inside the shroud at the intake and air outside the shroud where it enters the opening in front of the radiator lead one to believe that there is a huge difference which can mean timing pulled by a hotter temperature inside the shroud. Thus many conclude it is beneficial to cut the shroud so the outside air can be beneficial in lowering the temp at the intake.

To satisfy my curiosity, I mounted a remote temp sensor at the inside of the shroud right next to the mouth of my K & N intake and compared it's readings with the ambient outside temp shown on your air conditioning dash display. That ambient temperature is measured by a sensor that is mounted at the lower right end of the shroud and penetrates the shroud to measure air in front of the radiator.

I monitored those temps during idle, during acceleration, during cruising at various speeds, and after a hot shutdown and restart about 20 minutes later. During my testing, the outside temperature was generally in the 80's. What I found was that under most conditions of cruise and acceleration at almost all speeds that the max difference between the two temps was about 3 degrees, and most of the time the difference was 1 to 2 degrees. With a hot engine idling at a stoplight for about 3 minutes, the inside shroud temp could get up to about 5 degrees warmer, but as soon as the light turned green and the car was moving again the temp difference quickly went back to the 1 to 2 degree range within a 1/4 mile or so. After running the car at operating temp for about a half hour, I parked in a parking lot and went shopping. Returning some 20 minutes later and starting it up the difference was signicant. The inside shroud temp exceeded the outside temp by about 30 degrees. However, upon hitting the road again, after less than a mile, the two temps were again within a couple of degrees.

Granted, my experiment was less than a tightly controlled scientific one; but I did satisfy myself that temps outside and inside the shroud are very close to the same for most driving conditions. That seems reasonable to me, since if you closely inspect the shroud it is open at the bottom on both sides to the outside, and also is a loose fit where it's center mounting bolts hold it in place. In other words, it is designed to allow the engine to breath outside air through those openings. Ram Air intakes such as Vararam or Vortex may gain some increase in power through the ram effect at very high speeds at the track or strip, but as far as their cut shrouds producing a big colder temp to the intake, I couldn't find anything which would support that claim. Thus, I have concluded that for most drivers, changing the stock intake will only improve power if there is less restriction through better design and larger filter area of the replacement intake.

I should also mention that I have tried cutting my shroud and intalling a Vortex, and my dyno results seemed to indicate turbulence was actually reducing my power, instead of improving. I replaced the cut shroud with a new stock shroud and installed the K&N intake at the suggestion of my tuner. A subsequent dyno run showed much improvement and evidently no more turbulence which allowed a higher power result from the retune.

Anyway folks, that's my story, and I am satisfied with what I ended up with: an uncut shroud and a bigger area, lower restriction, K&N intake.

 

 

With the 370Z aftermarket intakes that claim 15+ gains we have found out that it wasnt the design or material used but the fact that the MAF tubing was slightly larger in diameter which we found out leaned out the car some and that was where most of the gains were coming from. I dont know of the aftermarket intakes for the vette are doing the same thing to get their gains or not.

 

I think that reputable manufacturers basic design and flow measurement/testing feedback to maximize flow is where the payoff is. Anybody can build a tube with a filter on the end of it, but getting it to function in a manner that maximizes stable flow, without turbulence, to benefit the engine is the art and requires good knowledge of the basics of fluid mechanics. The K&N factory website contains a lot of informative facts about this whole subject and explains testing procedures for anyone interested.

Separate comment: S'vette, please fill out your profile so we know who you are.

 

I guess I didnt word some of it well, I didnt mean that the aftermarket CAIs for the 370Z were made badly or designed badly (as they cost a fortune), I was menaing that the stock intake is already very well designed and made. And from what Ive seen on this forum so far, so is the Vettes. So to be able to get more gains they did a little trick of making the MAF tube slightly bigger to lean out the car some as most cars run rich, and this was netting some gains. I think sport cars are coming equiped with well designed products and tuned highly from the start, so netting gains on them means rethinking things now.

 

What is your objective. Will you be drag racing?

 

I think also that adding an after market intake should be considered only one part of the overall mod package to obtain the desired result. The final objective should be to obtain the performance desired for the use planned which may involve porting, headers, exhaust system, tuning, etc. Expecting to get some kind of super benefit from just changing out the factory intake is dreaming; and many after market vendors hope you do this when you read their inflated advertising.