The phrase "uprated version" refers to an improved or upgraded edition of something. It means that there have been modifications or enhancements made to a product, making it better or more powerful than its original version. Full definition
New OVERFINCH 570 Ti (Torque inject ion) announced.High value performance conversion achieved by interfacing 5.7 litre power with uprated version of original ZF automatic transmission. (overfinch.com)
The Boxster packs 330 hp and the Cayman 340 hp (both are equipped with uprated versions of the 3.4 - liter flat - six). (automobilemag.com)
That's what Hennessey believed, anyway, when they stretched and the baby Lotus to accommodate a massively uprated version of the 6.2 - litre V8 from the Corvette ZR1. (evo.co.uk)