The factory B4x/B58 heat exchanger is not built to cater to the rigorous demands often associated with a modified build. The thin core is easily overwhelmed with IAT's rising dramatically once pushed beyond a few successive WOT pulls or even a few minutes at the track. This elevation in temperature gives way to the factory ECU fail safes pulling timing and reducing overall power in order to keep the system from overheating to the point of permanent damage. On an application where enjoyment is directly attributed to pushing the platform to its limits this constraint to cooling presents a challenge for the automotive enthusiast. The Dinan B4x/B58 heat exchanger for the F2x/F3x chassis assists in mitigating these issues with a more robust core (48mm thick Dinan core vs. 27mm thick OEM core) that wields 78% more heat transfer surface area for improved cooling capacity. The significant increase in core thickness requires unique "L" shaped end tanks to be incorporated as well, which also contributes to the overall thermal mass (ability to absorb, store, and release heat) improvement beyond the OEM setup. With up to a 15&deg IAT delta recorded over stock the Dinan heat exchanger is ready, and able, to assist in extending your vehicles ability to deliver maximum performance time and time again for your driving enjoyment!