Here’s How You Can Take Your Honda Civic Si to Almost 300 HP

Next up, the 1.5-liter turbo four-cylinder engine needs to breathe a little better for bigger output numbers. Following the filter and intake manifold, you also need to change the original downpipe for a less restrictive unit.

Daelen says the factory exhaust “is not really of a limitation at all, but it’s really quiet and that’s really boring.” As long as the system doesn’t sound like a rattling can, the aftermarket exhaust is definitely worth installing.

Due to the OEM intercooler’s predisposition to heat soak after a pull or two, a beefier unit is also worth your consideration. “This is kind of going to be where you’re going to limit that factory turbo, factory engine car,” adds Daelen. Although the 1.5-liter mill can handle more as is, the spinny boy won’t be able to compress as much air as the engine needs to make more horsepower and torque. That being the case, a high-quality aftermarket turbo is mandatory if you intend to exceed the 300-horsepower barrier.

Even with the factory turbocharger, MAPerformance’s director of business development recommends a heavier-duty clutch kit. The FX100 from Rialto-based Clutch Masters, for example, is advertised with a 70-percent increase in holding capacity of the factory clutch and a price of $520.

Larger and stickier tires plus larger brakes also make a huge difference in conjunction with the upgraded engine and exhaust system. Stage 1 Civic Sis on premium gasoline are capable of churning out 230 to 250 wheel horsepower and circa 270 pound-feet (366 Nm) while Stage 2 cars are good for 290-odd horsepower and 320 to 350 pound-feet (434 to 475 Nm).