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) |
|