Does GSC S1 camshafts require upgraded valve springs?GSC S1 camshafts for the EJ255/EJ257 require upgraded valve springs to ensure optimal performance and prevent valve float at higher RPMs.What is the recommended installation process for these camshafts?Professional installation is highly recommended for GSC S1 camshafts to ensure precise timing and secure fitment, maximizing engine performance gains.GSC Billet S1 Camshaft Kits for Subaru EJ255/EJ257 with Intake AVCS deliver a significant surge in horsepower and torque, achieving an 8/10 score for Street Performance. Featuring a 268 intake and 266 exhaust duration, these billet camshafts are engineered for enthusiasts seeking substantial gains. Unleash your EJ255/EJ257 engine’s full potential with confidence and exhilarating acceleration.Key FeaturesSubaru EJ255/EJ257 (USDM) w/Intake AVCS S1 Cams 268/266 BilletWhy Choose the GSC Billet S1 Camshaft KitsDelivers a significant surge in horsepower and torque across the RPM range.Achieves sharper throttle response for a more connected driving feel.Provides enhanced top-end power for exhilarating acceleration.Transforms your engine’s breathing for maximum performance potential.Who Is This For?Street Performance 8/10Designed for EJ255 EJ257 engine performance enhancement.Engine Performance 9/10Billet camshafts designed to unleash engine potential.Racing Competition 7/10Premium performance camshafts for competitive applications.Track / Autocross 7/10Enhances engine performance for track use.Drag Racing 7/10Performance camshafts suitable for drag racing.Frequently Asked QuestionsWhat GSC camshaft is best for my 2004-2007 Subaru Impreza?The GSC Billet S1 Camshaft Kit is specifically designed for your 2004-2007 Subaru Impreza EJ255/EJ257 engine with Intake AVCS. This billet camshaft kit offers a significant surge in horsepower and torque across the RPM range. You can trust its advanced design to unleash your engine’s full potential.How difficult is it to install the GSC Billet S1 Camshaft Kit?Professional installation is recommended for the GSC Billet S1 Camshaft Kit, confirming with a qualified technician. This ensures the advanced components are integrated correctly for optimal performance. Rely on expert installation for confidence in your engine’s enhanced capabilities.What performance gains can I expect from the GSC Billet S1 Camshafts in my EJ255/EJ257 engine?Expect significant engine performance gains with a usage score of 9/10 for “Engine Performance.” The GSC Billet S1 Camshaft Kit delivers a significant surge in horsepower and torque across the RPM range. These billet camshafts are engineered to unleash your engine’s full potential.What is the best use case for the GSC Billet S1 Camshaft Kit?The best use case for the GSC Billet S1 Camshaft Kit is “Street Performance” with a usage score of 8/10. Designed for EJ255 EJ257 engine performance enhancement, these camshafts provide sharper throttle response for a more connected driving feel. Enjoy a transformed driving experience.Additional ResourcesOfficial GSC Power Division Product PageImportant Notices CARB Notice: This product is NOT legal for street use in California under CARB (California Air Resources Board) regulations. For off-road or race use only. Proposition 65 Warning: This product can expose you to chemicals including lead and/or other substances known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.{“@graph”:[{“mpn”:”7025S1″,”sku”:”GSC7025S1″,”name”:”GSC Billet S1 Camshaft Kits”,”@type”:”Product”,”brand”:{“url”:”https://www.gscpowerdivision.com/”,”name”:”GSC Power Division”,”@type”:”Brand”},”offers”:{“@type”:”Offer”,”price”:”999.28″,”seller”:{“url”:”https://www.motorsportmayhem.com”,”name”:”Motorsport Mayhem”,”@type”:”Organization”},”availability”:”https://schema.org/InStock”,”itemCondition”:”https://schema.org/NewCondition”,”priceCurrency”:”USD”,”priceValidUntil”:”2027-05-24″},”category”:”Camshafts”,”description”:”Delivers a significant surge in horsepower and torque across the RPM range. Achieves sharper throttle response for a more connected driving feel. Unleash the full potential of your EJ255 EJ257 engine with 268 266 billet camshafts.”,”isRelatedTo”:{“name”:”Camshafts”,”@type”:”Thing”},”alternateName”:”GSC Power Division S1 Camshafts Horsepower”,”additionalProperty”:[{“name”:”Feature”,”@type”:”PropertyValue”,”value”:”Subaru EJ255/EJ257 (USDM) w/Intake AVCS S1 Cams 268/266 Billet”},{“name”:”Street Performance Rating”,”@type”:”PropertyValue”,”value”:”8/10″},{“name”:”Engine Performance Rating”,”@type”:”PropertyValue”,”value”:”9/10″},{“name”:”Racing Competition Rating”,”@type”:”PropertyValue”,”value”:”7/10″},{“name”:”Track / Autocross Rating”,”@type”:”PropertyValue”,”value”:”7/10″},{“name”:”Drag Racing Rating”,”@type”:”PropertyValue”,”value”:”7/10″}]},{“@type”:”FAQPage”,”mainEntity”:[{“name”:”What GSC camshaft is best for my 2004-2007 Suba