This journey all started from an innocent question posed to our team last spring, “Can I bolt your HPA intake manifold onto my Stage 3 APR kit and make power?” The answer; Yes!

Fast forward seven months later, and the topically “simple” answer is realized with results going well beyond the brilliant lift in both the TQ and HP curves for Steve’s pristine stage 3 Golf R.

Steve delivered his ultra low mileage Golf R to HPA headquarters here in Langley BC for some upgrades. The chassis, brakes, and engine were all slated for some well sorted improvements.

In went a set of KW V3’s and a custom nickel finished set of HPA big brakes were installed at the front and rear axles.

Under the hood a less invasive upgrade was commissioned; our cast aluminum 2.0T performance short runner intake manifold was to be installed, dyno tested, and the software updated to optimize if necessary.

This was an interesting opportunity as Steve was running the latest and greatest calibration from APR and had only 4-5000 miles on this Stage 3 hardware set.

Prior to installing the intake, we strapped the R onto our Superflow AWD30 rolling road, fired up the 150mph wind machine, and made a few baseline captures. The numbers were solid for a 2.0T tipping 416ftlbs of TQ and 418HP on US 92 octane. (hub dynos like the ones APR use deliver higher output numbers than actual load based dynos like the Superflow). This capture would allow our team to have an apples to apples comparison.

Oddly enough, the strong dyno results were not reflected on the test drive where the APR Stage 3 kit seemed to have a lengthy delay in responding to 1/3 or 1/2 throttle input.

Our team hammered in the HPA cast intake and strapped the car back onto the rollers where a small amount of TQ and HP were gained with no software adjustments; a WIN for all the APR owners out there, but Steve wanted MORE!

Being our first experience with this APR package, we restored the ECU to OE and began calibrating. Almost immediately we could tell things were not as they should be...

After weeks and months of study we concluded the following:
The APR kit is configured around a set of OEM fuel injectors which are running flat out at 100% duty cycle
The rail pressure valve has been replaced with an aftermarket one manipulated to deliver 155 bar rail pressure
The APR ignition map runs -4 to +4 degrees of ignition.
Steve's Golf R exhibited the following issues:
A new cam follower had already lost its coating (after less than 5000 miles) and become indented from trying to push an additional 15 bar beyond the factory accepted performance augmented RS4 configuration.
The low ignition maps allowed for strong boost without knock threat but came at the cost of throttle response and drivability.
There was simply no more headroom for the ECU to take advantage of the higher capacity air volume delivered by the HPA cast aluminum intake manifold.
The Solution: an HPA Upgrade Package for APR Stage 3 Owners
Updated rail pressure valve (140 Bar RS4)
Upgraded injectors (Audi OEM)
HPA Cast Aluminum Intake Manifold
HPA Software Calibration

With our calibration, the injectors are now living between 74-85% duty cycle offering comfortable headroom. The rail pressure no longer lives at 150+ bar, rather a nice and realistic 125-128 bar so the demands on the OEM in-tank fuel pump, HPFP and cam followers are back within their intended specs for performance and durability. Plus, we enable all OEM safety within the software and have active knock protection.

The result is a smoke and burble free 40 ft-lbs gain in torque on US 92 octane, an average gain of 35HP and nearly 50 extra horses at redline, with the entire system backed away from the limits. We run a 2 bar boost map for 92 octane with headroom to grow beyond 460 ft-lbs of torque once internals such as rods and piston ring lands are addressed.

Steve took delivery of his R and after a day of enjoying it, a short message was thrown back to our team;

“Car is simply awesome! Great power and wicked fast. The difference is the way the power comes on... 1/3 – 1/2 throttle input power is immediately available – Thanks for the great work!”

This was a hard nut to crack as the underlying concepts for the original tune were based on injectors that were too small for the task. Jacking up the rail pressure places extreme demand and wear onto the cam followers, and as fuel filters and in tank pumps run their natural life cycle, there is zero tolerance for deviations.

This new package thunders in TQ and HP gains, uses refined ignition strategies to liven up the performance delivery, and keeps the entire system well off the OEM durability limits.