{"product_id":"denso-nat-l-245a-gm-6-grv-1-wire-powermaster-48550-1-alt","title":"Denso Nat'l 245A GM 6 Grv 1 Wire Powermaster 48550-1 Alt","description":"\u003cp\u003eThe only alternator rating most people are familiar with is the amperage rating.\u003c\/p\u003e\u003cp\u003eAlternators are referred to as a 65 amp or 100 amp alternator.\u003c\/p\u003e\u003cp\u003eWhen replacing the alternator on the family car, this is likely the only information necessary.\u003c\/p\u003e\u003cp\u003eHowever, when building a custom car from the ground up, a deeper understanding of the power curve of an alternator is required.\u003c\/p\u003e\u003cp\u003eA custom pulley or so-called 'power pulley' set is usually used with a performance alternator.\u003c\/p\u003e\u003cp\u003eA mismatched pulley ratio and alternator will spell trouble, especially at idle speeds where alternator performance is critical.\u003c\/p\u003e\u003cp\u003eUnderstanding the alternator's capability at slow speeds is important to avoid this.\u003c\/p\u003e\u003cp\u003eAn alternator's output is dependent on speed, but this can be deceiving because this output is not linear.\u003c\/p\u003e\u003cp\u003eInstead, it follows a curve.\u003c\/p\u003e\u003cp\u003eEach alternator has a unique curve, and at idle, small changes in the alternator's speed can make a significant difference in its output capacity.\u003c\/p\u003e\u003cp\u003eBecause of the preceding, pulley ratios are very important, especially when using high amperage alternators.\u003c\/p\u003e\u003cp\u003eThe pulleys supplied with the alternator are matched to the winding and power curve.\u003c\/p\u003e\u003cp\u003eIt is important that any dress-up pulley sets do not deviate from this ratio.\u003c\/p\u003e\u003cp\u003eA street-driven car should typically have a pulley ratio of at least 3:1.\u003c\/p\u003e\u003cp\u003eIf the vehicle has an automatic transmission with a low idle and spends a lot of time cruising, then a higher pulley ratio - perhaps 3.5:1 - should be used.\u003c\/p\u003e\u003cp\u003eAlternators can handle high speeds up to 20,000 RPMs for short periods, so overdriving the unit is not a problem.\u003c\/p\u003e\u003cp\u003eThe output of high amp alternators can drop off substantially under 2400 rotor RPMs.\u003c\/p\u003e\u003cp\u003eTherefore, Powermaster does not recommend power pulleys with high amp alternators.\u003c\/p\u003e\u003cp\u003ePowermaster uses a state-of-the-art computer alternator dyno to measure the performance of each alternator manufactured.\u003c\/p\u003e\u003cp\u003eOutput curves, engine idle speeds, and alternator pulley ratios are carefully considered to assure good drivability at idle and slow cruising speeds.\u003c\/p\u003e","brand":"Powermaster","offers":[{"title":"Default Title","offer_id":51739619131674,"sku":"PRM841233-1","price":352.42,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0975\/8942\/8506\/files\/71aOvaWVrWL.jpg?v=1771871214","url":"https:\/\/trybeepbeep.com\/products\/denso-nat-l-245a-gm-6-grv-1-wire-powermaster-48550-1-alt","provider":"TryBeepbeep","version":"1.0","type":"link"}