Our first encounter with German VW tuner HGP was at the Continental Tire top-speed shootout at Nardo in 2007, where the company’s twin-turbo Golf R36 ran to a spectacular 327.6 km/h (204.75 mph) before its unmodified DSG gearbox gave up the ghost under the sustained onslaught of 543 hp. When you consider that Nardo’s banking scrubs a few mph from a car’s true top speed, this totally street-legal Golf is probably capable of a genuine 207 mph on a flat autobahn in neutral wind conditions.
The next encounter was in a recent issue of Germany’s Auto Bild Sportscars magazine, where the HGP twin-turbo Golf 530 RS went head-to-head with a stock 500-hp Porsche Turbo PDK at the Sachsenring racetrack. Normally, a tuned hot hatch has no chance of matching a similarly powerful Porsche Turbo on a timed lap, but the HGP Golf recorded exactly the same 1:36.86-second lap time. The Porsche may have reached a higher terminal speed on the long straight, but the two cars had the same average speed of 136.44 km/h. Because there is no R32 version of the current Mk 6, HGP grafted Mk 5 R32 mechanicals into the newer shell, and then added its own twin-turbo kit. Why? Because you can get more power out of a twin-turbocharged V6, and because like us, HGP’s staff prefers the spine tingling V6 engine note to the flat drone of the four-cylinder 2.0T.
However, unless you are prepared to spend a lot of money having HGP build you a replica of this car, the fastest HGP cars will now be based on the new Golf R and Scirocco R models. The white Golf R I’m driving today is the development car to which HGP’s affable founder, Martin Graf, has just fitted his latest power upgrade kit. This conversion is still a couple of months from being signed off, and there are wires for test instruments hanging out from under the dashboard.
Graf would normally never let a car undergo a press evaluation until it is completely ready, but in this case, let’s just say that a certain amount of arm-twisting was involved.
What I said previously about the latest 2.0T FSI motor being incapable of matching a twin-turbo V6 is simple physics. As the saying goes a good big ’un is always better than a "good little ’un." Even so, the 460 hp that results from HGP’s comprehensive upgrade is nothing to be sniffed at. For a car that’s not quite finished, the HGP Golf R looks and feels very up and together. You only have to look at the thought that went into the design of the new components and their sheer quality to see that HGP is a company that takes the position and quality of every last nut and bolt very seriously.
To make this clear, Graf shows me the sand-cast alloy intake manifold, larger high-flow intercooler and hybrid turbocharger with high-nickel content cast-iron exhaust manifold. He then uses the silicone hose sections to connect these components around a mythical engine to show me how the new breathing arrangements work.
"The final piece in the puzzle is our in-house ECU remap that makes everything work as it should," he adds. While many tuners farm out ECU remapping, this is something Graf does himself. "I work with OEM equipment and application software and am online to Bosch," he says. "It is easy to work with Bosch ECUs, but the new Siemens ones are a problem."
The stock Golf R motor makes 265 hp and 255 lb-ft of torque from a tuned version of the motor from the Golf GTI Mk 5 rather than the latest Mk 6. The cylinder head is modified and uprated pistons, connecting rods, high-flow injectors, larger turbo and intercooler fitted.
"Using that as a basis, we lower the stock 9.8:1 compression ratio to 8.6:1," Graf says. "There are two ways of doing this, the expensive way being to replace the pistons with new low-compression ones, which involves a complete engine rebuild."
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
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
Peak Power: 450 hp (HGP est.)