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Twin Turbo Heffner Audi R8 & VFE Supercharged Audi R8 - Boosted Rockets

Stasis Engineering Supercharger VS. Heffner Motorsport Twin-Turbo

Les Bidrawn
Dec 2, 2010 SHARE

So you’ve just left the Audi dealer in your new R8. You’ve worked hard for this day, put in countless hours. You deserve it, dammit. You’ve pretty much got the world by the balls right now and everyone is going to know it.

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Of course, no one told those two R8s a few miles back. As they close on your six, a quick stab of the throttle should leave them behind, at least make them keep their distance. You’re the man after all, an Audi R8 man.

Something’s wrong. You’ve firewalled the pedal and these guys are getting closer. The pair blow by with power to spare. The world relaxes as you release your grip. You start weeping with the sudden realization you’re just an everyday Joe again. It’s not fair. You’re driving an Audi R8 after all.

No matter how brutal the beast, there’s always another capable of unseating it. In regard to the pair on these pages, two methods of forced induction left these cars with enough grunt to make a stock R8 seem rather pedestrian.

While few would consider the 420-hp R8 underpowered, there is a select group who need more, significantly more. Currently there are two proven methods to wrest more power from the 4.2-liter Audi mill: turbocharging or supercharging. Both methods are effective and offer their own unique driving experience. Should the factory ever decide to force-feed the V8-powered R8, it’s anyone’s guess on which method they’d choose. Audi has explored both to great effect.

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Stasis Engineering and technology partner VFE have been at the forefront of forced induction development for nearly a decade. VFE supercharging systems have ranged the full gamut, everything from VR6 Corrados to V8 Spykers. Working closely with the crew at VFE, Stasis supercharging systems blend hammer-like durability with a 30-45 percent power increase. Oh yeah, and Stasis guarantees it you’ll be happy with the results, fours years/50,000 miles worth of happy.

We have been working with Nik Saran at VFE since the R8 was first introduced says Henry Hsu, lead engineer for Stasis. A lot of testing went into this system, a lot of development.

It possessed the kind of robust durability Stasis demands in its products. Using our highly detailed manual, an Audi tech can install the system in a mere 16 hours.

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Available at more than 55 Stasis dealerships throughout North America, Hsu trains R8-certified Audi mechanics to install and service the supercharger system at Audi dealerships. As a former lead engineer for Porsche Motorsport, Hsu relocated to Stasis headquarters in West Virginia.

It’s a little different than Southern Cali, but our facility is on Summit Point Raceway which is awesome for testing. And we are just 40 minutes from Audi’s corporate offices so the location makes sense.

Like its predecessors, the Stasis R8 supercharger system is engineered to deliver a substantial performance boost from a genuine bolt-on system. Using the proven Magnuson/Eaton roots-type charger, CAD-designed manifolds and mounting systems, high-efficiency intercoolers/charge coolers and superbly coded GIAC software, you’d be hard-pressed to differentiate an idling Stasis-equipped R8 from a stock vehicle. In addition to retaining excellent low-speed drivability, the VFE R8 delivers a stunning punch to the torque curve. A few tics over 2000 rpm and this car is putting down 250 lb-ft of twist, 140 more lb-ft than a stock R8. Keep pushing and by 4500 rpm you’ll see 436 lb-ft with a maximum 539 hp realized at 7350 rpm. To deal with the newfound power, OEM Plus swapped the clutch and flywheel with a V10 unit, an upgrade that bolts right in.

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Hard-core Audi enthusiast Bill Vogel sent his Ibis White R8 to Stasis Engineering where it was outfitted with the supercharger system.

The car has been absolutely perfect, said Vogel. I track this R8 quite a bit and it behaves brilliantly. I think that says something about the Stasis supercharger system. It’s the same during regular street driving as well. This R8 behaves just like a stock vehicle, only faster.

The crew at OEM Plus added several elegant touches including the carbon fiber trim packages for the engine bay and body. The mirrors are PPI-designed pods covered in carbon fiber caps. The cabin features four-point racing harnesses, Hexomat floor coverings and a PDR100 Chase Cam camera with a DM10 data acquisition system.

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Beneath the spokes of the factory wheels we saw cross-drilled Brembo rotors gripped by Pagid yellow pads. Tires were the new Pirelli Trofeo measuring 245/35 in front and whopping 305/30 out back.

As an instructor in the Audi Club, Vogel drives his R8 the way nature intended-hard. A mile before he arrived at our canyon rendezvous point we heard the R8’s glorious engine riffs bouncing from the rock walls. Breathing through a high-performance Stasis exhaust, this Audi sounded more like a superbike than a street car.

It’s a pretty aggressive tone, Vogel says. I’ve been thinking about swapping it for something less vocal. But when I come up here it’s totally worth it.

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A few minutes later, another R8 joined us. This Phantom Pearl Black Audi was decidedly quieter than its sibling and yet packed just as much punch. A pair of turbos will do that.

Heffner Motorsports, in Sarasota, Fla., used its years of turbocharging experience with cars like the Ford GT40, Dodge Viper and Lamborghini Gallardo, a car we tested in the Dec. 2007 issue. On the blistering hot streets of Willow Springs Raceway in the Mojave Desert, we drove the Heffner twin-turbo Gallardo for the better part of a 100-degree day with the A/C on full-blast. No hiccups, no burps, no spurting fluids, the Lambo survived our hi-temp mischief with power to spare. That night, we hit 205 mph on the access road and probably could have gone faster with a bit more pavement and a fresh set of tires. Suffice it to say, Heffner has forced induction down cold.

We’ve taken the R8 engine apart, Jason Heffner recalls. It’s a very solid V8, very robust. It’s a good candidate for forced induction.

For this setup, Heffner chose Garrett T28 dual ball bearing turbos with upgraded compressor wheels. The wastegates are 44mm TIAL units with APR diverter valves.

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We could have gone either bigger or smaller with the turbo sizes, Heffner says. The T28s allow us to retain good low-end performance that extends to the upper reaches of the rpm band. We wanted the characteristics of a big engine-no turbo lag or peaky torque band.

All the extra piping, plumbing and exhaust works were designed and fabricated in-house, with an emphasis on OEM-level fit and compatibility. The ECU is the factory Bosch unit, re-programmed by the vaunted performance geeks at APR.

As for the intercooler itself, it’s a liquid-to-air cooled unit utilizing Garret/Honeywell cores. Heffner designed it to fit between the intake runners and the intake manifold. The R8 exhales through Heffner’s own thermally treated stainless steel exhaust. This car was fitted with one of its more sedate exhausts, a unit every bit as quiet as the factory system. Heffner has a more aggressive system if necessary. The rear clip of the car must be removed for installation, a procedure that takes some 40 hours of labor.

The extra power is routed through the more robust V10 clutch and flywheel, bits installed by OEM Plus.

Like the white car, OEM Plus did their thing to the R8 utilizing hard-to-find bits from Audi’s closet. This car wears the V10 R8 side skirts and carbon Sigma side blades. The taillamps are Euro spec units featuring amber blinkers. OEM Plus sourced a RNS-E unit for the LCD interface screen that provides quicker processing and graphics. The factory 19-in wheels were fully polished and shod in Pirelli P Zero rubber measuring 245/35-19 in front and 295/30-19 aft. The rotors were swapped for 380mm cross-drilled Brembo units.

I’d spent time in the supercharged R8, enough to realize the extra power moves the R8 into supercar status. Torque is everywhere and continues until the engine is wailing for a gear change. The tone is glorious, perhaps a bit on the raw side and similar to the Lamborghini Gallardo.

In contrast, the twin-turbo version was unnerving in its quietness. A few times I almost restarted the car for lack of noise. However once the throttle is pressed, this thing launches itself with extreme prejudice. Unlike the supercharged version, the twin-turbo R8 takes a few microseconds to get busy but catches up quickly, ripping through the first four gears fast enough to outrun a nuclear blast. The best analogy is that of a well-modified 911 turbo, a bit more polished but every bit as urgent.

Running on 98 octane and six psi, both cars have similar power, besting the V10 by a few ponies. The supercharged version had slightly better low-mid range throttle response that made it easier to drive on our tight road course. However, given a more open environment, I think the twin-turbo car would have had the edge with better upper rpm response and more top end.

At the end of day these cars essentially mirror each other’s performance. There are slight differences in the power curves but the designers and software engineers have done such a superb job tuning it’s a non-issue. In its favor, the Stasis supercharger program is supported with a factory warranty. In the same way Alpina works with BMW, Stasis works with Audi. It does not get much better than that.

The Heffner system is damn fine too, not quite as refined as the Stasis kit but just as potent. Despite our heat-related concerns, Heffner has done well in the cooling department. Moreover, it wouldn’t take much to tweak the system for even more performance. Of course, you’re on your own but some people like it that way.

I could go on and talk about plans these two have for the V10 R8but that’s another story.

Additional notes
I did find something interesting when crunching the numbers, the Heffner quotes the stock R8 at 353.20 hp at the rear wheels on 93 octane showing a 16% drivetrain loss while the VF R8 quotes 347 hp at all four wheels on 91 octane showed 17% drivetrain loss based on 420 crank hp. What I found was that eliminating the load from the front drivetrain makes no difference on the R8 unlike the 5% decrease in powertrain loss I have seen in the past on VW and Porsche AWD vehicles. LB

2009 Audi R8 (Ibis white)

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Layout
Longitudinal mid engine, all-wheel drive

Engine
4.2-liter V8, DOHC 32-valve, supercharged

Transmission
Six-speed manual

Suspension
Aluminum double wishbone, Audi Magnetic Ride

Brakes
Eight-piston calipers with 14.4-inch cross-drilled Brembo rotors, Pagid Yellow pads (f); four-piston calipers with 14-inch rotors, Pagid Yellow pads (r)

Wheels and Tires
OEM forged alloys, 19-inch
Pirelli P-Zero Trofeo
245/35 (f), 305/30 (r)

2009 Audi R8 (Phantom Black Pearl)

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Layout
Longitudinal mid engine, all-wheel drive

Engine
4.2-liter V8, DOHC 32-valve, turbocharged

Transmission
Six-speed R tronic automated manual

Suspension
Aluminum double wishbone, Audi Magnetic Ride

Brakes
Eight-piston calipers with 14.4-inch cross-drilled Brembo rotors, Pagid Yellow pads (f); four-piston calipers with 14-inch rotors, Pagid Yellow pads (r)

Wheels and tires
OEM forged alloys, 19-inch
Pirelli P-Zero 245/35 (f), 295/30 (r)

Turbo VS. Supercharger

There’s an old adage that says that numbers don’t liebut they can be misguiding when taken out of context. Based on the peak power numbers alone, one could assume that the Heffner R8 TT upgrade is the clear winner. But oftentimes, the devil’s in the details. I played detective and delved deeper into the differences between the numbers and here’s what I uncovered.

When comparing numbers, you have to make sure you aren’t comparing apples to oranges. From years of doing the Proven section for ec, immediately when I looked at both dyno charts, a few thoughts popped into my head.

First, these runs were done on two completely different dynos. The Heffner was run on a DynoJet versus the VF on a Mustang. It’s common knowledge that DynoJet hp numbers are on average about 10-15% higher than Mustang hp numbers. Plus, there are inherent differences between any dynos even if they are from the same manufacturer.

Second, the rwhp on the Heffner graph indicates that they only measured power generated at the rear wheels where VF’s graph indicated all four wheels were used. An all-wheel-drive dyno will have lower numbers which reflect the parasitic drag from the front wheels and since rear-wheel drivetrain loss is less, more power reaches the wheels, inflating the numbers.

Third, the Heffner run used 93 octane which will add 10-20 whp on a forced induction vehicle and the VF engineering graph used 91 octane.

Finally, the Heffner turbocharger installation comes as a package with an exhaust and intake system where the VF is running a supercharger on a stock intake and exhaust. Adding an exhaust system to a stock R8 can add 16-21 whp and an intake system can add 8-10 whp.

On both graphs it’s unclear what run is being represented- is it the 1st, 2nd, 3rd or 6th? Modern vehicles typically show big gains in the first run before the ECU has adapted or the car has completely warmed up.

The same R8 looks completely different whether it’s turbocharged from Heffner or supercharged by VF. Before you compare numbers and shell out money for the obvious choice’ look further. A better comparison would be to equip the VF R8 with an intake and exhaust and run both vehicles on the same dyno, with the same fuel octane, and testing conditions.

Heffner R8 Twin Turbo VF R8 Supercharged
Dyno Type DynoJet Mustang
Horsepower Acquired Rear Wheels Only All Four Wheels
Peak Power 536.48 hp @ 122 mph 439 hp @ 7650 rpm
Test Octane 93 91
Exhaust Full turbo back Stock
Intake High flow Stock
Boost 6 PSI 6-7 PSI

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By Les Bidrawn
242 Articles

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