How loud do you like it? Chapter One: Intake

One of the most common complaints new owners have about their S2000 is that it’s “too quiet.” The feeling seems to be that a sports car with this kind of performance ability should sound a bit more ferocious.

There are a number of ways to add motor music to your S2k, but we’ll discuss the two most common this week: intake and exhaust.

Both the stock intake and exhaust on the S2000 are extremely well designed units. While a cold air intake or free-flowing exhaust system can increase horsepower as much as 20% over some OEM systems, don’t expect any more than a 1-6HP gain with even the best aftermarket intakes and exhausts on an S2k.

Let’s look at some options…

Many S2000 enthusiasts agree that the best “free” modification available for an S2000 is the removal of the stock airbox cover. Simply unlatch the snapping clamps holding it in place and pop the cover off. You’ll suck more hot air in from the engine compartment this way, so your horsepower will actually decrease very slightly. (usually between 1-3 HP) Most agree that the sound is worth it. The engine gives off a nice growl that becomes a healthy roar when V-tec engages. If you feel the HP decrease, just put the cover back on. No harm, no foul.

There are really three other types of intakes available for the S2000.

The short ram intake is the loudest. It theoretically provides the most rapid throttle response due to its shorter length, but may suffer from drawing more hot air as a result. Short Rams are also not smog-legal in many states.

The second option is the long tube intakes such as the offerings from AEM and Injen. These relocate the air filter to behind the front bumper drawing cooler air from the ground. The longer tube length translates into slightly slower throttle response, but the HP difference on a very hot day can be as much a 5-7. This is also the least convenient setup as the bumper needs to be removed to clean or replace the filter. Most of these intakes are CARB approved. (the AEM V2 being a notable exception) Because of the low location of the air filter, extra precaution needs to be taken in wet conditions. While driving, deep water, puddles, splashes, and heavy rain bouncing off the road can all get sucked into the low mounted air filter. Even a car parked in rain isn’t necessarily safe. Water can wick down the intake and collect in the air filter. When water gets into the filter, it can easily be sucked into the engine and cause “hydro-lock,” a usually terminal condition. AEM sells a bypass valve that can be installed to guard against the possibility of hydro-lock.

The third option relocates the airbox further from the engine to provide cooler air. This is the quietest of the three options, since the filter is enclosed, but they still provide a nice little boost in tone over the factory unit. The Comptech CAI is a perfect example of this type. Because the filter is still enclosed in a box, there is no chance of hydro-lock. In the case of the Comptech, Mugen, and J’s intakes, the heavy factory airbox is replaced with a much lighter carbon fiber one which contributes nicely to the quality of the sound as well as weight reduction.

Don’t expect any intake to make much of a difference in your S2k’s power, but the sound can make your driving experience that much more enjoyable. Check back Saturday when we’ll discuss exhaust options.