Engine at the test stand
The HOREX VR6 engine has been installed on one of the engine test stands at the Munich University of Applied Sciences since mid-2010. Prior to this, comprehensive functional and endurance testing was conducted over several weeks on the test stand to adapt the specific requirements of the HOREX engine.
The work involved fabricating a custom-made fixture for mounting the engine to the test rig, adapting the hoses for cooling, fuel, etc., and connecting all electrical components. These included the alternator and spark plugs, as well as a variety of sensors that precisely record all technical parameters during the test runs.
Renowned engine designer Rupert Baindl played a key role in the test runs and the work on the test rig, which was closely coordinated with the heads of the Institute for Internal Combustion Engines and Vehicle Drive Systems at the Munich University of Applied Sciences, Prof. Dr.-Ing. Werner Bauer and Prof. Dr.-Ing. Martin Doll.
Critical components for the test runs included the exhaust system that was specifically designed for the test rig. This custom-made system ensures a leak-proof connection to the exhaust extractor and also provides space for mounting additional sensors, including the six oxygen sensors for precise combustion diagnosis.
The specially designed test system does not correspond 1:1 with the future series standard. Consequently, the characteristic VR6 sound of the engine – which can be heard on the video and the audio file – is probably a little throatier during testing operations than it will be in the street version.
Following initial functional testing, a series of endurance tests were performed on the engine. These correspond to real-world riding for tens of thousands of kilometers. During this phase, all data from the HOREX VR6 were continuously monitored. Experts from Motul, our lubricant supplier, took engine oil samples at regular intervals. These samples were analyzed to determine engine wear during the trial runs. The oil analysis results and precise measuring of all disassembled engine parts clearly showed that the engine design team did an outstanding job. All parameters were "well within the target range" following long-run endurance testing.
After they achieved satisfactory results for engine durability, the HOREX engine designers naturally wanted to test the accuracy of the performance data based on the simulations. The results brought satisfied smiles to the faces of the team members. The VR6 engine is "well-aspirated" – though it wasn’t revved up to the max the power output measured on the dynamometer was about 150 hp and above.
After the most critical parameters were established, the test rig is currently being used for basic engine tuning. This primarily involves fine-tuning of the electronic system and developing the engine operating map. For this phase, the development team is supported by Ewald Mayer, an experienced application engineer.