CB463-6002: Stage 1 S63 TU4 High Performance Engine: F95 X5M & F96 X6M

Stage 1 S63 TU4 High Performance Engine: F95 X5M & F96 X6M

Steve Dinan has been building high performance and racing engines for BMW since 1977, winning 11 racing championships including 3 prototype championships and two 24 Hours of Daytona. The same engine shop that builds the racing engines also builds the street car engines. These talented engineers, machinists, and builders have built hundreds of engines from OEM street rebuilds to full-blown racing engines.

From stock, the S63 engine is not designed for a large increase in boost. CarBahn has designed a high-performance engine to handle very high outputs by utilizing higher quality racing Carrillo connecting rods and forged CP pistons.

For our Stage 2 engines, high performance direct injection camshafts are reground to increase the stroke on the direct injection pump to increase fuel flow for higher boost levels. We also port and polish the cylinder heads.

The stock engine compression ratio is relatively high due to the Corporate Average Fuel Economy (CAFE) standards which push for consistently higher fuel economy in cars and trucks. However, this increased compression limits engine performance with higher boost settings by decreasing the size of the fuel-air charge in the combustion chamber, forcing the ignition timing to retard far below MBT (Mean Best Timing, the theoretical optimal ignition timing). Therefore, the Carbahn Autoworks S63 engine has 0.5 less compression to optimize the engine for the increased boost. In an emissions-legal street car, the lowered compression has the added benefit of reducing catalyst inlet temperatures and improved drive-ability on pump gas.

Engine core acceptance parameters

Must be complete core (factory engine, from oil pan to valve cover)

• Block must have no:
  • Holes or cracks in casting
  • Holes or crack in covers
  • Bore damage that cannot be honed out
  • Thrust surface damage
  • Journal surfaces damage
  • Bolt hole damage that can’t be repaired
• Heads must have no:
  • Holes or cracks in casting
  • Holes or crack in covers
  • Thrust surface damage
  • Journal surfaces damage
  • Bolt hole damage that can’t be repaired
• Additional repair charges could apply for damaged items that are not normally changed during an overhaul and cannot be repaired or serviced
  • Valves
  • Crankshafts
  • Camshafts
  • Guides
  • ValveTronic mechanism
  • Vanos mechanism