Complex sentence: The engine was still a 2.2 L 910-series, but with many performance-enhancing modifications that included enlarged inlet ports, cylinder head modifications, a re-calibrated ECM and a revised turbocharger.
Split into simpler sentences: The engine was still a 2.2 L 910-series, but with many modifications to improve performance. The changes included enlarged inlet ports, cylinder head modifications, a re-calibrated ECM and a revised turbocharger.