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On the other end of the engine, we fitted another Hotshot component: their cold air intake, or CAI. This modification not only netted more power, colder and more consistent intake temperatures, a remote filter that fit directly behind the foglight hole in our Euro P10 bumper to allow for a ram-air box, but also reduced a lot of clutter under the hood. A less cluttered engine bay allows for faster servicing, a definite bonus on any racecar.
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| Many an SE-R owner will recognize this part as Hotshot's Cold Air Intake. |
We replaced the older style oil-impregnated cotton filter that came with our Hotshot CAI with an oil-free AEM DryFlow air filter and AEM air filter wrap. Using AEM's DryFlow filters offered us a number of advantages over our old filter. First, it reduced the number of times we needed to service and clean the filter. This was a boon to us because the space our home-made ram air box could fit into did not allow for easy servicing. Adding the air filter wrap extended the service life of our filter even more, and gave us some added protection from foreign object damage (FOD). FOD is a major concern with anything on the front of a racecar, since gravel is almost always on the track, and R-compound tires are especially adept at throwing them at the car behind them. Second, cleaning the AEM DryFlow is a snap: simply remove the filter, lightly tap it against a hard surface to remove loose dirt and debris, spray with AEM's Dryflow cleaner, rinse, dry and re-install. No need to oil the filter, and no worrying about applying too much or too little oil, especially important on Mass Air Flow (MAF) sensor-equipped cars like our G20. Lastly, our original filter didn't seem to be doing its' most important job: removing dirt. The inside of our intact tract featured a light coating of dust, and our oil analysis showed elevated silica levels (indicating excessive dirt getting into the engine). Racecar engines are stressed enough as it is, we certainly didn't need to add to that. A light coating of grease was applied to the inside of the filter where it clamps onto the intake to prevent any dirt from sneaking by between the filter and intake tube.
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| AEM's DryFlow filter and pre-filter replaced the oiled cotton filter we were running previously. With the older filter, we were having issues with dusting on the inside of the intake tract that have been solved with this filter. The pre-filter will not only increase our maintenance intervals, but will also help prevent FOD. |
To further keep our inlet temps down, we enlisted the help of Outlaw Engineering's ThermoBlok spacers. Made from phenol resin laminate, these spacers keep the intake manifold cool by greatly reducing the heat transfer between the cylinder head and intake manifold. Since icing was not a concern, we also removed the stock coolant recirculation in the throttle body. Because our underhood temperatures were higher than what you'd expect to see on most any street car, we needed all the help we could get. Even directly after a race, our intake manifold was still indiscernible from ambient. Expect to see intake temperature data in the near future for this project.
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| Outlaw Engineering sent us some of their intake manifold spacers. Made from phenol resin laminate, these spacers keep the intake manifold cool by greatly reducing the heat transfer between the cylinder head and intake manifold. Expect to see inlet manifold air temperature data from us soon. |
With the engine's breathing taken care of, we moved on our engine's valvetrain. As with every stock engine with single profile camshafts, our stock camshafts were a compromise between emissions, power, tractability, and driveability in bumper to bumper traffic. Since we were primarily concerned with power output in racing conditions, none of these OEM considerations applied to us. Luckily, Nissan enthusiasts have a company that's just as passionate about making cars go fast as we are, and also happen to have the talent to produce some really well engineered products. To ensure optimum power between 5000 and 8000 rpm with the stock cylinder head, we ordered up a set of Jim Wolf Technology (JWT) C3 camshafts and JWT valve springs.
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| Our complete valvetrain upgrade consisted of JWT's C3 camshafts, cam gears and valve springs. |
