Why is an idler-tensioner necessary?

KRC's idler tensioner is essential on dirt cars. Belt slippage can occur on cars that exceed 7,000 RPM and/or use a large diameter or heavy fixed fan blade, or a fan blade with a lot of pitch. Potentially causing the engine to overheat and the pulleys to wear faster. This shows up on both single drive belt systems and pulley system with the power steering pump mounted on the front of the engine.

The reason for this problem is the centrifugal force coming from the fan as it decelerates. The fan belt and pulleys are required to work like brake shoes to slow the fan. It stretches the belt allowing it to slip while braking, inducing heat into the belt. The belt will continue to stretch as the race goes on, allowing the temperature of the engine to slowly climb. After extensive testing, we have found the only way to properly tension the belt to prevent slippage is with an idler pulley mounted on the passenger side of the engine. This helps your engine run cooler and keeps the belt tighter, allowing you to accelerate faster out of the turns, while also allowing you to brake harder on corner entry.

	Idler-Tensioner Kits KRC Idler-Tensioner kits are available separately, or as part of KRC's single belt serpentine pulley drive kits. Available for Chevrolet and Ford. Dodge coming soon.
	Alternator and Idler-Tensioner Kits KRC's Idler-Tensioner is also available with a solid 138mm Denso alternator mounting bracket. Never worry about charging your battery between heats. Plus it will provide your engine constant voltage through the entire race. This will keep your spark plugs hot, resulting in no drop off in power. Also available as a single belt serpentine drive kits. Available for Chevrolet only. Ford coming soon. Alternator sold separately.