I am trying to upgrade the turbocharger on my 2007 Volvo C30 T5 from the stock K04 to something larger and capable of supporting 350-400bhp.
I followed Garrett's website which allowed me to generate a spreadsheet of values, however I am running on several assumed values.
I have measured the manifold pressure of the stock turbo at ~16psig at full boost, and measured the current power to be ~250bhp (flywheel estimate from rundown measurement of drivetrain dynamic losses). The max RPM is 6500, displacement 153.8ci, peak torque at 3500rpm.
I have estimated the AFR (12:1), intake manifold temp (160F), HP per lb/min (9.9), BSFC (0.56/hr) and the engine volumetric efficiency (91%).
This has calculated a stock turbo pressure ratio of 1.98, with actual airflow at peak RPM of 28.11 lb/min, and at peak torque of 14.92 lb/min.
To support 350 bhp, I have calculated a pressure ratio of 2.70, actual airflow at max rpm of 39.20 lb/min and actual airflow at peak torque of 20.80 lb/min.
Does this seem reasonable? and what turbo can support this increase?