GSC Power-Division billet S1 cams for the VVTi Toyota Supra 2JZ-GTE. The S1 cams are designed for those running an upgraded single turbo larger than 57mm. These cams will not have bottom end losses over stock cams with larger turbos; nothing but gains, and will promote an extremely flat torque curve. Gains of 40-70 WHP (depending on turbo) have been seen by simply bolting the S1 cams in and reshimming with a proper tune. These cams require a single valve spring upgrade over stock.