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C6 Corvette Vararam Cold Air Induction Kit

February 10th, 2009
Cold-air induction-or ”CAI”-kits are typically among the first things enthusiasts add to
their Corvette. And why not? They’re affordable, generally pretty easy to install, and offer a real-world performance gain. CAIs for the C6 come in three general styles: open element, cold air, and ram air.   

The open-element filters are installed in place of the factory air cleaner
and draw ambient air from the engine compartment in the same fashion as
the stock unit. They usually employ a large, open-element filter with
some sort of cotton-gauze media and nix the flow-restricting shroud.
These tend to be slightly less expensive than the other systems because
they’re smaller and less complex. Installation is a snap because they
require no cutting or modification of the car.

Cold-air systems draw
outside air from the cavity in front of the radiator and
air-conditioning condenser. From a performance standpoint, this type of
system is preferable to an open-element filter, as it delivers cooler
outside air to the engine rather than relying on the hot air found
underhood. Most cold-air systems use a panel-style filter and a housing
mounted to the radiator shroud.

A ram-air system, such as
VaraRam’s two-piece Snake Charmer, takes the cold-air concept one step
further. Instead of simply drawing air from beneath the radiator
shroud, the VR’s lower housing employs a forward-facing scoop situated
directly in the path of oncoming airflow, behind the grille.

The downside is that ram-air
systems require a hole to be cut in the radiator shroud in order to
access that outside air. In itself, this is not a big deal, but many
would-be modifiers balk at the notion of cutting holes in their
brand-new car. If that’s you, this is not your intake.

There are
a myriad of manufacturers building these systems, and some of them make
pretty bold performance claims. For instance, VR says the Snake Charmer
will add 40 or more horsepower. When pressed, company reps quickly
explain that this claim is only valid for speeds of over 100 mph, when
air is actually being forced into the scoop. (In support of that
notion, VR says the system will add 8-10 mph to the C6′s 186-mph top
speed, a claim we were unable to verify without risking long-term
incarceration.)

VR also claims that, at
speed, the Snake Charmer creates a positive pressure (similar to a mild
supercharging effect) in the intake system. But try as I might, I was
unable to verify this through the use of a boost gauge or by monitoring
the car’s MAP sensor. Perhaps the effect is too subtle to be measured
with conventional instrumentation.

Typically, the power gain from
a ram-air system such as this one will be fairly modest on a stationary
dyno. There, the stock air cleaner does a relatively good job of
supplying air to the hard-working LS2. In fact, VaraRam requested that
we conduct our performance evaluation on the drag strip, as that is
where the performance gains purportedly become clear.

VaraRam offers two optional
items for the Snake Charmer. The first is a throttle body spacer that
effectively increases the intake manifold’s plenum volume and ought to
deliver a small power increase. This part was unavailable for our test,
however, so I can’t comment on its effectiveness.

Also offered is
a pre-cut radiator shroud, which I recommend you forego. It’s almost
guaranteed to double the install time, because removing the shroud is a
royal pain, involving partial disassembly of the car’s lower valance.
Do yourself a favor and carefully cut your existing shroud. If you do
wish to replace it in the future, new ones are as close as your
favorite GM parts house for about $40.

Performance Testing

Minor fit and finish complaints aside, there’s no question the VaraRam delivers a marked improvement in performance.
While I would still like to see a more thoroughly finished piece for
$400 (retail), I say the VaraRam is a solid performance investment.

Note: DA-corrected numbers are parenthesized.

0-60 Times
Pass Time
1 4.26
2 4.05
3 4.09
4 4.04
5 4.11
Average 4.11 (3.92*)
Stock Average* 4.24 (4.02*)
Improvement 0.13 (0.10*)
*NHRA correction factors are not designed for 0-60 testing,   

so this number is offered for comparison only.

Quarter-Mile Times/Speeds
Pass ET MPH
1 13.44 110.9
2 13.48 110.8
3 13.42 111.0
4 13.39 111.2
5 13.41 111.1
Average 13.43 (12.80) 111 (116.5)
Stock Average 13.61 (12.89) 108.4 (114.5)
Improvement 0.18 (0.09) 2.6 (2.0)

 

 

 

Step-By-Step Instructions:

    

If size were the only
consideration, the OEM intake assembly would look pretty
impressive-it’s huge! Unfortunately, its design limits it to sucking
hot underhood air.

 

    

Disassembling and removing the
stock intake should only take a couple of minutes. Start by pulling the
locking key from the MAF sensor’s weatherpack connector.

 

    

Then pull the weatherpack from the sensor.

 

    

Remove the PCV vent from the inlet bellows, as shown.

 

    

Now, loosen the hose clamp that secures the air bridge to the MAF sensor.

 

    

The air bridge can now be
pulled loose from the MAF. This may take a little bit of effort, as the
interference fit can be rather tight in some cases. The bridge “ears”
may pop loose from the radiator cover in the process, which is no
problem.

 

    

The next part to come out is
the broad shield shown here. There are no fasteners holding it in
place, so a firm yank ought to liberate it.

 

    

The filter
housing is now ready to vacate the premises. Be original, and put it on
eBay. Maybe you’ll be lucky and score a Buy It Now deal for more than
the three cents it’s worth.

 

    

Though the directions gloss
over this completely, a bit of further disassembly will ease your
suffering-a little. Removing the radiator top cover will allow you
access to the back side of the shroud. (You’ll see why in a minute.) Do
this by removing the four bolts holding it in place. Don’t forget to
unclip the hoses on both sides.

 

    

With that, the cover is free.

 

    

Locate the VaraRam template for
the shroud and cut it out. The instructions say to tape it in place on
the shroud as shown. In my case, this positioning proved to be too low,
and I had to do some additional trimming to get the housing properly
positioned.

 

    

Trace the template using a silver Sharpie, White-Out or a grease pencil.

 

    

Slide a chunk of cardboard or thin plywood in front of the condenser to shield the condenser from your cutting implement.

 

    

A firm hand is all it takes to puncture the shroud. Assuming you are using a new blade, it cuts like butta.

 

    

Here’s why the cutting and
cussing are necessary. You’re looking at the business end of the
VaraRam: the scoop that is situated behind the grille. The design is
impressive-looking, if not quite as solidly constructed as I would like.

 

    

The lower housing is as viewed
from above. Note the foam seal. You’ll want to inspect this to be sure
it is properly affixed to the housing. If not, you risk a leak, which
could allow unfiltered air and debris to bypass the filter.

 

    

Looking up the throat of the
upper housing shows noticeably higher construction quality. Be sure to
check this gasket for adhesion, as well.

 

    

Here’s the junction between the
lower and upper housings, which contains the Green high-performance
panel filter. It uses deeply pleated cotton to create a 15 percent
increase in filtration area over conventional filters.

 

    

The fit of the upper and lower
pieces left something to be desired, as shown here. VaraRam assured me
this is normal and nothing to fret over. Not convinced, I looked for
leaks with a flashlight. Finding none probably means there are no huge
leaks, but I’ll be keeping an eye on the MAF sensor screen for debris
just the same.

 

    

Prior to re-installing the radiator top cover, remove the air-bridge-retention pins.

 

    

The VaraRam is best installed
assembled, as shown. This will make aligning the entire system a whole
lot easier. As mentioned earlier, the cut-out shroud required some
additional trimming in order for the unit to drop all the way into
place.

 

    

You’ll know everything is in alignment when the MAF can be easily slid into the supplied silicone hose.

 

    

Now you can fasten the
VaraRam’s red anodized bracket to the forward bulkhead, using either
the original fasteners or the supplied socket-head cap screws.

 

    

Install the included hose clamps, being careful not to over-tighten. You can also reconnect the MAF harness and the PCV hose.

 

    

The scoop positioned behind the grille is very subtle. If you didn’t know it was there, you’d likely miss it completely.

 

    

And here is the finished product, as seen from the engine compartment.

 

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