Stage 4.5


We are delighted to offer our latest upgrade path which produces a thrilling 700bhp and over 600lbft of torque.

Throughout 2012 Stage 4 was our most popular upgrade but despite also doing a huge number of Stage 5 conversions it became clear that not every customer desired the massive 130bhp jump and investment required to go all the 
way to our 750bhp Stage 5. Stage 4.5 is designed to cater for the customer looking for the next step without all the associated costs. Our Stage 4.5 package takes power to 700bhp with a carefully selected turbo combination and high flow fuel pumps in addition to the normal Stage 4 upgrades.

These new turbos use the existing IHI core but receive CNC machining to accept a larger Spec V style turbine wheel and our proven billet compressor wheel.


Why go for a Billet Compressor Wheel?

  • Approximately 30-40% lighter than the cast original Compressor wheel
  • Weight reduction gives a significant improvement to transient throttle response
  • Faster Turbo spool up for less turbo lag
  • Advanced CNC accuracy for improved aerodynamics
  • Larger blade length due to reduced CNC hub size
  • Extended Tip design for increased airflow
  • Machined from solid Billet for additional strength


Combining these upgrades allows the engine to develop a comfortable extra 80bhp over Stage 4 whilst still retaining fantastic response and driveability. The high flow fuel pumps deliver more than enough capacity whilst remaining silent and keeping fuel temperature down.

Power now extends all the way to the redline offering a much larger power band.

The Stage 4.5 Power upgrade includes:


  • Genuine Garrett upgraded waste gate actuators
  • Twin high flow fuel pumps
  • Litchfield 1,100cc Bosch Injectors
  • Litchfield Large Bore performance intake kit with larger MAF housing
  • Milltek Cast Stainless Steel Downpipes
  • 90mm Milltek Stainless Steel Y-Pipe
  • 90mm Milltek rear Stainless Steel exhaust system
  • Improved boost control with custom Ecutek code
  • Revised ignition control, Variable Valve timing and Fuel maps
  • Reduced fuel consumption (especially on partial throttle conditions)


  • Increase in both power and torque across the whole rev range
  • Litchfield RACEROM Switchable maps for enhanced Economy mode and full Race mode
  • Litchfield Custom Launch Control settings when used with Gearbox Software upgrade
  • Freshly recharged Air Conditioning system
  • Litchfield Engine cleanse
  • Litchfield High performance 5w-40 engine oil

The Stage 4.5 package costs £9,995 fitted inc. VAT
Upgrading from Stage 4 with downpipes already installed costs £5,472 fitted inc. VAT
Upgrading from Stage 4 with without downpipes already installed to costs £5,946 fitted inc. VAT


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