After the APR K04 performance upgrade, I had to do an engine overhaul and rebuild, which was completed in end of February 2020. Karl, Isaac and team rebore the engine block and replaced a slew of components, including:-

• Wossner pistons (for all four pistons)
• Conrod and main bearings
• Timing belt
• Water pump
• Oil pump
• Pressure control valve (PCV)
• High performance spark plugs (NGK BKR9)

The whole new bundle with labour costs me around RM13,900.00!

After a run-in period of 5,000km I had the car dyno tested again (but please take note that from mid-March there was a Covid-19 Movement Control Order (MCO), so since I hardly got a chance to drive my car, as we had to work from home, it took me a while to cover the required distance). Below are the results dated 18 July 2020 (this is the third dyno test) :-

VW Golf GTi - Dyno TestPJ Home, Lorong Utara, Petaling Jaya, Selangor.

After engine rebuilt / overhaul.
APR K04 HPFP Intercooler Stage 3.

iPhone 6s Plus - 13.6

As you can see from the above graph:-

- the red coloured line is the original test before K04 upgrade,

- the blue line was after the K04 upgrade,

- the orange line was after the engine rebuild.

After the engine rebuild, there is a noticeable difference in surge by as much as of 50 Nm in torque at around 3,200 rpm, with a strong pull from as early as 2,500 rpm until 5,200 rpm. In fact, there is also an increase in power by as much as 30 PS at around 3,200 rpm, and certainly a good boost of power from 2,700 until 5,200 rpm. Compared to the original (although I already had done Stage 2 upgrades), I improved about 70 PS and 98 Nm! So now, my car has a max of 281 PS and 412 Nm (which is more than the Renault Megane RS at 280 PS and 390 Nm)! What can I say, the car just feels really, really good  ｡^‿^｡