The more economical, but no less sound way from an engineering point of view is to put a precisely machined metal gasket between the block and cylinder head. This is what HGP does. A larger 10mm fuel pump together with 40 percent larger high-flow injectors is used to keep up with the thirst of the modified engine. The intake starts with a free-flowing K&N air filter.
The Garrett turbocharger with 500-hp output capability is built to HGP’s specifications and features a larger scroll housing than stock with a small turbine wheel for faster spool time. The larger intercooler, with its 63mm thick core, is far more efficient than the OE unit and, along with the lower compression ratio, provides the lower charge air temperatures to safely support the higher boost pressure. This in turn feeds a 70mm throttle body. The stainless steel cat-back exhaust system uses 88mm stainless-steel tubing, which strikes a fine balance between reducing backpressure, and losing gas velocity.
Optically, this exhaust has twin central end pipes like the R32. It also features a third catalytic converter with a throttle body to supplement the OE primary cat, downpipe and secondary cat, and help the uprated engine meet the tough EU5 emissions standards. "Unlike some tuners, we don’t have an export only’ exhaust system," Graf says. "I can easily get 480 hp using 1.8 bar of boost. But here in Germany, some customers drive flat-out down the autobahn for long stretches, so customer cars are rated at 446 hp on 1.7 bar."
From a handling point of view, the factory turbocharged four-pot motor has a major advantage in being a good deal lighter than the V6. This is especially so when you strap a pair of turbochargers and a big intercooler onto the V6 where they do the R32’s already nose-heavy weight distribution no good. To ensure the car’s handling matches its newfound power, HGP worked with KW for an uprated suspension system. "We use complete spring and damper kits for the older models, but only springs with the Golf Mk 6 and Scirocco," Graf says.
To maintain good weight distribution, the battery is moved to the back, where it is on the R32, and HGP’s big-brake kit with big, red-painted calipers sits behind the 8.5x19 OZ Racing alloys shod with 235/35 ContiSportContact tires.
Around town, the HGP Golf R drives like a standard car, and with the uprated DSG gearbox working perfectly in the background, is docile enough for your granny to drive to the shops without getting a heart attack. The DSG’s speed and its ability to keep the motor spinning in its sweet spot at all times is a big bonus. So is the all-wheel-drive 4Motion system, as the big hit of torque that arrives like a gentle tsunami when you go to full throttle would not be a pretty sight if you had to deploy it through just the front wheels. As it is, there is no drama, no histrionics, just a steady and really strong thrust as the gears slip from one to the next and the speedometer and rev counter needles rise like a pair of world class dancers going through their slick, choreographed performance.
It’s only when you glance at the speedo that you realize how fast you’re going, and more than that, how fast you’re picking up speed. Close to 450 hp in the relatively light Golf makes serious velocities as easy as the proverbial A-B-C.
The HGP Golf R is impressive, and makes far more power than I thought a street-legal four-cylinder motor ever could. This is one hell of a stealth machine that can seriously upset some supercar drivers. As modded four-cylinder Golfs go, this car is the business, especially as the raw quality of the conversion matches any and all expectations.
So what’s missing? It all comes back to that charismatic R32 soundtrack. As smooth and powerful as the 2.0T FSI is, its impressive empirical performance lacks the soul of the V6 whose god-given ability to tap right into your synapses and juice the pleasure center of your brain makes it such a special experience for the enthusiast.
You can blame government legislation for that. In the cold, hard light of day, the fact is that no naturally aspirated V6 can ever be as clean or as economical as a state-of-the-art turbocharged four. Only in these circumstances outside HGP’s control is a good small ’un better than a good big ’un.
HGP Golf R
Transverse front engine, all-wheel drive
2.0-liter I4, dohc, 16-valve, turbocharged. K&N air filter, 10mm fuel pump, high-flow injectors, Garrett turbocharger, custom intercooler, 70mm throttle body, custom stainless steel cat-back exhaust
Six-speed DSG automated manual
KW springs, OEM dampers
HGP big-brake kit
Wheels and Tires
OZ Racing alloys, 8.5x19
Continental ContiSportContact 3, 235/35
450 hp (HGP est.)