Case Study

“The LS single intake runner passed our heat and pressurization tests with flying colors.”

928 Motorsports turned to Stratasys Direct Manufacturing to cost effectively manufacture their intake manifold runner. Stratasys Direct Manufacturing's Project Engineers worked closely with 928 Motorsports to select the ideal process and material to meet the geometry’s unique features and requirements. Selective Laser Sintering (LS) was chosen for testing the intake runners, utilizing the excellent properties of Nylon 12 GF, a nylon material filled with glass beads to greatly enhance the physical properties of parts built with this material. LS was chosen for its functionality and strength so the runner would not break when bolted to the engine, ensuring form and fit. This process allowed for changes to the intake runner to be made immediately and avoided the expense of tooling.

“The LS single intake runner passed our heat and pressurization tests with flying colors.”
– Carl Fausett, 928 Motorsports

After preliminary testing had been finished and 928 Motorsports was satisfied with the fit and contours of the model, a final prototype was produced. The design needed to confirm that the intake could experience up to 20 psi of boost pressure on the supercharged racecar. Stratasys Direct Manufacturing then went to work on manufacturing a single intake runner for their destructive testing. They were able to apply 200°F and 20 pounds of pressure to the Nylon 12 GF intake runner. The pressure cycle was repeated 6 times a minute. 928 Motorsports needed to know how much of the nylons’ strength would be lost because of the high temperatures. Additional testing involved raising the manifold pressures from 20 psi to 40 psi, the temp from 200°F to 220°F, and logging over 16,000 cycles. There were no measurable changes or failures. Carl Fausett of 928 Motorsports remarked that “the LS single intake runner passed our heat and pressurization tests with flying colors.”

The final tests proved that the runner could handle the under-hood temperatures and pressures it needed to succeed in the given application. Lastly, the engine was fitted with the LS composite runners and taken to a dynamometer, where it remarkably produced more than 860 BHP.

LS production began as a way to build prototypes early in the design cycle, but it is now being used to manufacture end-use parts such as this intake runner. LS allows for parts that are durable, functional, heat and chemical resistant, and lightweight. Because of the structure of this geometry and the material used, this engine could fit under the hood of the Porsche thanks to the weight reduction and high heat resistance associated with LS.