Is unfortunately English, but I found it very interesting. Comes directly from Borg Warner: Quote: Dear Sir, thank you for your interest in our products. First of all, we don’t produce any turbo that we call K03S. But I hope I can answer your questions with the following explorations. All the following turbos have the same installation dimensions and thermodynamic performance. The differences are only in the actuator that opens the turbine bypass valve: K03-011 (5303 988 0011) 150 hp, 6 5 N actuator K03-026 180 hp, 85 N actuator K03-035 180 hp, 85 N actuator K03-044 150 hp, 65 N actuator K03-045 156 hp (Ibiza Cupra), 85 N actuator with 2 ports K03-049 150 hp (Sharan/Alhambra), 65 N actuator The 180 hp versions have an actuator with a higher opening force due to the higher exhaust gas pressure (which is a consequence of the higher boost pressure). Otherwise the value would be pushed open by the exhaust gas pressure. The following turbines are a further development (s since) 2000) and have an improved and slightly larger compressor while using the same turbine (still with the same installation dimensions): K03-052 180 hp, 85 N actuator K03-053 150 hp, 85 N actuator K03-058 150 hp/180 hp, 85 N actuator Consequentially, putting a 180 hp turbo on a 150 hp engine will not bring about any change in performance, but putting on a K03-052/053/058 instead of the older versions will bring a light improvement in engine efficiency. CU you can achieve about 215 hp without danger of overspeeding the turbo. With the older turbos, 195 hp is the limit. With the K04 that’s also commonly used (5304 950 0001) the power output should not be more than 220 hp. That means, changing a K03-052/053/058 against a K04 does not make a lot of sense. I hope that these details answer your questions. If you need more info, one of our service distributors will be glad to help you. Their addresses are on our website www.turbodriven.com. Best regards, BorgWarner Turbo Systems GmbH Sales IDS – Technical Support Christian Seibert