[Sam] is the lucky owner of a 1990 VW Corrado G60. To the uninitiated, that’s the souped-up, go fast version with the fancy supercharger on top. While performing some mods to the air intake (car-speak for “hacks”), there came a need for a custom tube to eliminate the original silencer box. With available options costing up to $400, suddenly 3D printing a replacement seemed like a better answer.
3D printing intake parts for a supercharged vehicle has some unique challenges. The intake must be able to take the boost pressures seen by the engine, in this case up to around 10 psi. There must be no air leaks at all as this risks confusing the sensors that measure how much air is entering the engine. Lastly, the tube must be able to withstand the hot, and often oily environment under the hood.
The first attempt was completed with TPU filament, which unfortunately did not hold pressure. A followup with PLA fared better, but was unable to withstand the heat present in the engine bay. After some experimentation, a successful print was made in PETG which was more robust. In the final design, [Sam] applied a rubber coating and then some aluminum tape, to both help seal any micro-holes in the 3D printed surface as well as help protect against heat.
After over a month of testing, [Sam]’s data logs indicate the tube is performing well and holding boost. It goes to show that with some perseverance and iterative design, 3D printed parts can often save the day.
Perhaps you’re inspired by this hack but need to jack up your car to work on it? Never fear, you can 3D print those too.