Happy New Year everyone!!
CXXIV posted on the Fiat 124 Forum today, something that I was not aware of – a Mopar belly pan that apparently supercedes Mazda’s belly pan, and was introduced for the MT Abarth 124 Spiders sometime during MY
2018 2017, and incorporates a NACA duct that I imagine helps in cooling the engine compartment (it appears to be directing air up the side of the engine with the cat/downpipe).
Per Antony Hayton:
The U.S. National Advisory Committee for Aerodynamics (NACA) became NASA in 1958. By then the NACA Duct was in common use on airplanes. It then became in use for race cars. It has a specific job. Objects that move through the air disturb it. Even a bullet stirs the air up. No matter if it be a plane or a road vehicle, airflow is disturbed as they go through it, causing turbulence. Turbulence is drag and drag eats up speed and increases fuel consumption. The NACA Duct came from the need to pull attached airflow into required spaces for various reasons (cooling, air conditioning, tank pressurization etc.) without using a high profile ram air scoop, which would create lots of drag, fuel and speed loss too. NACA Ducts use the air attached to the plane or car and suck it inwards. The air hits the gentle ramp angle and the curvature profile of the walls and creates counter-rotating vortices. The NACA Duct is the smart designed shape that tricks airflow with the least amount of drag, that would eat fuel and speed. It is designed specifically for a job, that it accomplishes passively due to it’s aerodynamic properties. It works automatically as speed increases.
I’m betting some initial production MY 2017 vehicles don’t have this feature, and until I hear otherwise, there is a possibility that Classicas and Lussos of any year might not either (I could be wrong). The Mopar catalog also implies that you get the non-duct belly pan with AT – why would that be? If you live in a hot climate, or are otherwise putting heavy demands on your engine, this may be a good option to consider, even if you have to fabricate the vent duct yourself. I only say that, because Mopar’s MSRP for this goody is $517! If you can bend some sheet aluminum, or perhaps 3D print a proper vent duct, and pop-rivet that into a hole cut into your existing belly pan, I think it could be done for around ten bucks 🙂
For guidance, simply bring up photos for Mopar part # 68313969AA (or simply purchase one). CXXIV shared this photo of the Mopar belly pan, with the Mazda belly pan behind it, for comparison.