The communication present results from work on development and evaluation of new polymeric carbon fiber composites with extreme temperature performance: Tg up to 360°C is targeted. The anticipated use of such composites is found in aeroengine-applications. In the work we are exploring a new and tailored phenyl ethynyl terminated imide (PETI) formulation, specially developed for the program. The formulation utilizes crosslinkers of the Nexamide" type (from Nexam Chemical AB, Sweden). The resins are initially evaluated from a processing and property perspective. Both DSC-measurements and rheology characterization are utilized in the development. Suitable RTM-processing schemes are investigated from a viscosity point of view. The schemes are used in the composite sample manufacturing. Besides a processing perspective the study also present the first results on physical behavior of the polymers and their composites.