I’ve recently updated the power calculator to include a turbo calculator. This calculator, performs similar calculations to the supercharger calculator in terms of flow and boost requirements to reach your power goals. It then goes out and chooses 10 compatible turbochargers that match your target application.

I’ve also added the calculations for the minimum size for a single or dual wastegate to properly regulate boost on this application.

After completing this update I sat and thought: “You know what, it wouldn’t take much more work to turn this into a twincharger calculator !” and that’s what I ended up doing.

The video below talks about my preferred twincharged setup which is a sequencial arrangement with a higher rated turbocharger feeding compressed air to a smaller , lower rated supercharger, feeding twicely compressed air into the engine.

In the video we cover the following topics:

  1. Preferred twincharged arrangement
  2. Air metering and the blow through system
  3. Using bypass valves to improve response
  4. Alternative arrangement for superchargers that are part of the intake manifold (and therefore can’t have an intercooler placed after them).
  5. A hands on example using the power calculator to twincharger the Toyota 5sfe engine to 320 horsepower (which is the same example I did the calculations for manually in my previous twincharged articles).

(Viewing time 27:00 minutes)

The Turbo Calculator calculates:

  • The required boost pressure and flow level to reach your power goal
  • Cold-side (Before the turbo) and hot-side (after the turbo) optimal intake piping dimensions
  • Optimal air to air intercooler volume and cross sectional area for your power, boost and flow levels
  • A selection of turbochargers that match your boost and flow requirements
  • The recommended turbocharger aspect ratio based on approximate spool rpm and calculated pressure ratio
  • Exhaust manifold dimensions (runner diameter, collector diameter)
  • Exhaust system dimensions (downpipe and cat-back system diameter)
  • Minimum wastegate bore diameter to maintain a stable boost curve
  • Fuel flow calculations: fuel pump rating, fuel injector size, fuel feed and return line sizes, and approximate water injection spray levels (optional)
  • Total ignition timing calculations based on peak boost, cylinder bore size, rpm, and spark plug arrangement
  • Optimal camshaft duration, and lift for your power goals, boost level and target redline rpm.
  • Optimal cylinder head flow and valve sizing for your engine’s flow demands
  • … and more

Click here to go to the turbo calculator page