Two years later can riding a 350 cc Velocette he won the first Eifelrennen, to claim the Deutsche Tourist-Trophäe, the inaugural race held on the Nürburgring.

1950 saw the first Großer Preis von Deutschland after World War II, at the Nürburgring, where he finished fourth in his open-wheel Veritas RS.

In this car, he also recorded a surprising third place in the Preis der Ostechweiz-Erlen [8] in Switzerland, beaten only by the Scuderia Ferraris of Luigi Villoresi and Roberto Vallone.

[10] He participated in two World Championship Grands Prix in 1952, debuting on 18 May 1952, in the Grosser Preis der Schweiz,[13] but retired due to fuel tank issues.

On the AVUS, lost a dramatic slipstream battle with fellow Veritas driver, Fritz Rieß, on the penultimate lap.

[10] Despite his retirement early 1953, Ulmen was soon, albeit briefly, behind the wheel, sharing a Jaguar D-Type with Herman Roosdorp to third place in his only 24-hour endurance race, the 1953 24 Heures de Spa Francorchamps.