This is because for every piston moving down a cylinder (potentially reducing the size of the crankcase and increasing the pressure), there is another piston moving up in a cylinder (increasing the volume of the crankcase and reducing the pressure).

While many high-end classes of racing from Formula One to Pro Stock rely upon dry sump oiling systems that run the crankcase at negative pressure (vacuum), few entry-level racecars and even fewer street cars benefit from the negative crankcase pressures of a dry sump oiling system.

The cost and complexity of a dry sump oiling system puts it out of reach of many.

Fortunately, the benefits of reduced crankcase pressure can also be accomplished by simpler and more cost-effective means.

These solutions may be achievable for under 100 to upwards of 1,500.

Even on the high-end, this may only represent less than 25 percent of the cost of a dry-sump oiling solution.

For those that can afford the expense, there is no substitute for a well-designed, high-quality dry-sump system and all of the benefits that can be delivered.

For the rest of us, the benefits of the lower-cost alternatives are well worth the cost.

Once a solution is employed to reduce crankcase pressure, the result is free horsepower.

This is free in the sense that no additional fuel needs to be burned to realize the power.

Instead, the reduced crankcase pressure is simply freeing up or realizing new horsepower from increased engine efficiency and reduced power losses.

At idle and under high vacuum, the PCV valve uses engine vacuum to reduce the crankcase pressure to zero.

However, when intake manifold vacuum is zero (or under boost), there is no intake manifold vacuum to reduce crankcase pressure, so the pressure gets directed to the compressor inlets.

In most cases, this will create positive crankcase pressure on the order of 3 to 6 psi, robbing performance.

Lower crankcase pressures (0-to-1 psi) result in better ring seal and increased performance usually on the order of a 2-to-3 percent increase in power.

The system also eliminated the issue of introducing oil from the crankcase into the compressor inlets, charge piping and intercooler.

The vacuum is typically regulated to run at -5 to -20inHg on most applications.

The negative crankcase pressures (a.k.a.

Performance usually increases on the order of 3 to 6 percent.

In the first part of the Less Pressure, More Performance series, we will define crankcase pressure and its causes before identifying the methods to reduce or eliminate crankcase pressure.

To demonstrate the real-world results, well dyno test a simple solution on our Project R35 and witness the magnitude of the results.

On the suggestion of David Buschur, we added a pressure sensor to our dyno to measure crankcase pressure on any car that we dyno test.

On engines using the factory designed crankcase ventilation system (a PCV or positive crankcase ventilation system), we typically measure peak crankcase pressures on the order of 2.5 to 6.0 psi when the engine is in normal running order.

Vented Catch Can G35