SPd Performance Reviews

The SPD Performance 170 degree performance thermostats provide better engine cooling which allows you to increase and maintain more consistent horsepower. You'll also obtain more precise metering of water throughout your engine—as well as a long product life, since the thermostats are made from stainless steel.

All late model vehicles have water pumps designed for fuel efficiency and not water flow. This causes hot spots within the block. By introducing cooler water to the block, you allow the limited flow of coolant to absorb more heat before exiting the block. This prevents the sensors from seeing block temps over 300 degrees, which could cause the PCM to start pulling timing and reducing power.

By grouping primary exhaust tubes into a collector, the vacuum pulse from one cylinder can be used to create a vacuum on the other exhaust ports. This vacuum will cause the exhaust to begin flowing more quickly as the exhaust valve opens. The collector must be long enough and small enough to keep the inertia of the exhaust pulse optimized while keeping back-pressure low.

You can expect an extra 1-2 mpg (results on 6.8L V10) because the engine is not having to force the exhaust. You will immediately notice that acceleration and maintaining cruising speed will take much less throttle.