Now supporting S14 Kouki ECUs (NA and NC sticker codes), all S15 ECUs and J4 (Kouki S13) ECUs.Free overnight shipping with all orders! Just remove your brackets from your ECU when you send it and we will overnight it back to you for FREE!!!Since 2001 R.S. Enthalpy has been perfecting the art of tuning ECU’s for the Nissan / Infiniti platform. After years of work and research on the dyno we are able to offer you a custom tune that makes more power and is safer than anyone else, bar none. But you already know this, and that is why you are here. Let us create a custom RSE tune for your SR, KA, VQ or VK powerplant.