V-Spec. Core Depending on the application and usage, some turbocharged set-ups require different flow characteristics. To add to our tuning choices, GReddy developed the V-spec. line of intercooler cores with an inner "Micro Grove Tube" design. This design was developed to allow for larger cores that give good cooling with a more free flowing internal core. This is ideal for applications with low to medium-high boost levels in factory turbocharged engines or normally aspirated engines with bolt-on turbo kits.