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Old 02-06-2023, 04:17 AM   #1 (permalink)
ademonrower
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Join Date: Feb 2023
Location: Germany
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A-Pillar aerodynamic modifications / fairings

Please read disclaimer at bottom.

Cars with prominent gutters on the A-pillars clearly have an aerodynamic disadvantage in comparison with (more modern) cars with concealed gutters, or no gutters. Without ruining the "look" of a (older) car, I've discovered quite a lot that can be done to make the gutter almost disappear. I've done the modification on a Volvo 245 (wagon / estate / break), without invasive measures or damaging any of the bodywork or shiny trim: I can take the modification off easily, and the car is exactly as it was before.

The modification is basically a hard-PVC slat made from the curved corner of some air-duct shaft, with some small lugs positioned on the trailing edge to locate it flush with the gutter trim, and two small brackets underneath - one top, one bottom - with a screw through them into the rubber of the windshield trim. I used a hot-air-gun to soften the PVC to modify the curvature of the end-parts. That was very easy. I primed the PVC and painted it the colour of my car.

I've driven 1,000s of km on motorways with the modification, and it has never come loose. On the antenna side, I additionally used the antenna screw-hole to affix it. Yes: antenna: additional advantage: I took the external A-pillar-mounted antenna off, and simply re-routed an antenna wire inside the slat: perfect radio reception, perfect solution for that annoying radio antenna :-) which also caused bad air-flow :-(

The "forward-facing" mod of the A-pillar is, of course, only half of the story, because to minimize turbulence AFTER the A-pillar (where there is a step-inwards towards the window) one should also fit a "fairing spoiler" to lead the flow in smoothly to the window glas. However, I haven't done it yet, and I also need to be careful not to obscure view out of that window :-) A small fairing made from perspex or similar, cut to shape, and heat-formed, could be quite easy to make... perhaps also quite easy to fit, but I haven't got that far yet...

DISCLAIMER: I take no responsibility for damage to life or limb if you make a similar modification on the basis of my modification described herein. I take no responsibility for damage to life or limb that may occur whilst driving with this modification fitted to your car. Use your common sense, do tests, and don't take any unnecessary risks. If anything falls off your car whilst driving, it can seriously injure, or even lead to the death of, another driver/rider or pedestrian etc.

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aerohead (02-06-2023), freebeard (02-06-2023)