probably around 2-4hp..
Horsepower can be increased in a Toyota Corolla by doing bolt-on additions. Connecting a cold air intake system and full exhaust system will increase the power of an engine by approximately 8 percent.
2007 corolla S auto 1.8 liter 40 mpg. 45 with a cold air intake my wife drives mostly freeway to work
Cut off catalyic converter and add a cold air intake system.also improves mpg
From 5 to 10 horsepower.
cold air intake
10 horsepower.
about 2 wheel horsepower
what year
The cold air intake may add 5-10 hp to the 335 it was built with.
http://www.tundrasolutions.com/forums/corolla-matrix/136765-2009-corolla-xrs-cai/ Hope this helps
Intake clearance COLD: 0.006-0.010 in. (0.15-0.25mm), Exhaust clearance COLD: 0.008-0.012 in. (0.20-0.30mm), Intake clearance HOT: 0.008-0.012 in. (0.20-0.30mm), Exhaust clearance HOT: 0.010-0.014 in. (0.26-0.36mm).
Ram air intake aka, short ram intakes are good for low end horsepower and torque Cold air intakes have more horsepower gaines then short ram and more top end power. If your looking for more torque then horsepower, meaning more acceleration but dont care about topping out your car, then short ram intake is what you want. If you already have enough torque and just want more horsepower and go fast as possible, then cold air intake is what you want.