Adding a new Blitz Blow Off Valve (BOV) to an aftermarket turbo system lead to no clearance between the valve and the hood of the vehicle. An adapter was needed to drop the BOV from the high pressure pipe outlet to between the twin cooling fans behind the radiator.
The problem statement is as follows:
A custom adapter was developed to accommodate hood clearance. Before final fabrication out of aluminum a prototype was “printed” using a Dimension Rapid Prototype Printer. The printed ABS parts are inherently porous and needed to be sealed in order to hold pressure. The part was dipped quickly in acetone and then washed thoroughly with soapy water to seal the pores. The part was then tested to 110 PSI on a test bench before failure. A second part was then tested on the car.
Because operating pressure is only 10 PSI, a FOS of 10 was provided by the design.
The second consideration is that the BOV is cantilevered off of the high pressure pipe bung . The BOV weighs approximately 1/8th of a pound. Adding this to the loading still produced a FOS of 5.
Simulation verified the physical test results and showed that the printed part holds up to the design requirements. The printed ABS adapter works so well an aluminum version was never fabricated. 110 passes down the 1/4 mile drag strip, 1000’s of miles, and 4 autocross seasons, and the little plastic adapter keeps on going.