2010 Hyundai Genesis Coupe by Rhys Millen Racing Full Test and Video

Hunkered down over its 19-inch wheels with its exhaust burbling, the 2010 Hyundai Genesis Coupe by Rhys Millen Racing (RMR) looks about as badass as any tuner car we've ever tested. Its wheelwells are absolutely filled with Toyo T1R rubber. And it's so low that there's not even room for a dime between the tires and fenders.

"Where's the kidney belt?" we're thinking to ourselves as we climb behind the wheel for our weeklong stint. See, we've done this before. We've driven plenty of tuner cars that have punished us unmercifully as we've driven down the road, the so-called suspension "tuning" feeling as if it had been accomplished by Neanderthals with stone tools.

So we were pleasantly surprised when we pulled out of the shop of Rhys Millen Racing in Huntington Beach, California, and found ourselves driving all of 10 feet before running straight over a set of railroad tracks. What happened next might seem not only unlikely but even impossible given the history of aftermarket tuning. The suspension — the moving parts under the car designed to soak up bumps — did exactly that.

And then for the next six days this high-performance Genesis Coupe built by RMR continued to soak them up. In fact, by the time our test of this car ended, this single trait continued to be so novel that we started running over bumps just to see what would happen. Tiny little square-edge stutter bumps on the freeway? Nothing to worry about. Big rollers at triple-digit speeds? Who cares? And the ultimate test: midcorner bumps when you're already near the grip limit? Not a problem.

This is how an aftermarket suspension should feel. And it's only one part of Millen's package for the 2010 Hyundai Genesis Coupe.

The Rest of the Story
Back in February, Hyundai dropped a bomb on the enthusiast world with its 2010 Genesis Coupe. The striking car has a 306-horsepower 3.8-liter V6 motivating its rear wheels, huge Brembo brakes (included as part of the Track package trim) and enough road presence to draw inquiries from mullet-wearing Camaro drivers — not typically the sort of guys you'd find curious about a Korean coupe. This is one of the biggest stories in performance cars this year.

And it just got bigger.

Rhys Millen Racing, the same outfit that campaigns a 2010 Hyundai Genesis Coupe in the Formula Drift Series with Red Bull sponsorship, prepared this mildly modified Genesis Coupe with some of the same parts used on its competition car and some cooperation with various aftermarket partners. The goal of the project has been to show what can be done starting with a Base or Grand Touring model Genesis Coupe, both of which cost less than the Track package and lack its aggressive suspension tuning, Brembo brakes, Torsen limited-slip differential and 19-inch wheels and tires.

Lightweight Exotic Parts
RMR has arranged the manufacture of a carbon-fiber hood and trunk lid for the Genesis, which together shave about 40 pounds from the coupe's curb weight (28 pounds from the hood, 12 from the trunk). The parts are essentially the same as those used by Rhys Millen's competition car, except the hood's vents and ducts are not cut out in this application for a street car, which seems smart.

Under the hood, carbon fiber replaces the stock pieces for the airbox lid and ducting, dressing up the engine bay and adding, Millen tells us, 6 hp. A K&N panel filter replaces the stock air filter. RMR has also bolted on an axle-back exhaust that uses 2.5-inch tubing, and Millen says the exhaust is good for 5 hp.

KW Suspensions supplies its Variant 3 pieces (coil-overs up front, separate springs and dampers in the rear), which offer adjustable damping in both compression and rebound. Meanwhile the new antiroll bars from RMR/Suspension Techniques are 3.1mm larger in diameter up front and 1.5mm larger than stock in the rear, and both are two-position-adjustable.

The 19-inch Enkei RPF1 wheels are shod in 245/40ZR19 front and 275/35ZR19 rear Toyo Proxes T1R tires, a combination that actually reduces weight by about 7.5 pounds per wheel. The Stoptech brake system (a prototype on this particular car) replaces the coupe's stock brakes with six-piston front and four-piston rear calipers. Stoptech's two-piece rotors are 14 inches in diameter up front and 13.6 inches in diameter in the rear. The combination increases both brake torque and thermal capacity.

In an effort to increase the coupe's leverage on the pavement under acceleration, RMR has replaced the stock 3.5:1 rear end with a 3.9:1 rear axle from the turbocharged 2.0-liter Genesis Coupe, retaining the Torsen limited-slip differential in the process.

At 3,414 pounds, the RMR coupe weighs 59 pounds less than the 2010 Hyundai Genesis Coupe 3.8 Track Package we last had on our scales, thanks in part to its carbon-fiber body panels. The Stoptech brakes, we figure, are a wash with the Brembos in terms of weight. Their two-piece rotors save weight, but are larger in diameter. Plus the six-piston front calipers are larger than the four-piston Brembos on a Track package car.

Going
Without big power upgrades, we weren't expecting major acceleration improvements from the RMR car versus a stock Track package car. (We haven't tested a Base or Grand Touring-equipped coupe, but all these variants make the same power when equipped with the 3.8-liter V6.)

Launching in the quarter-mile from about 4,000 rpm, the first few gears disappear sooner in the Millen car than in the stocker, forcing two shifts before achieving 60 mph, a speed the stock coupe will reach in 2nd gear because of its taller final drive.

Even so, the 60-mph milestone arrives in 5.8 seconds (5.5 seconds with 1 foot of rollout like on a drag strip), which is 0.1 second quicker than the last Track package Genesis Coupe we tested. This margin holds until the quarter-mile traps, which we reach in 14.0 seconds at 100.7 mph; the Track package car makes its pass in 14.1 seconds at 99.3 mph.

We didn't see any improvement in the RMR car's braking in our single-stop test. Hauling down from 60 mph to zero requires 117 feet in the RMR coupe. The last Track package-equipped car we tested required 111 feet to stop from the same speed.

There are several possible explanations for this, but we suspect the Toyo T1R tires, which have a higher treadwear rating than the stock Bridgestone Potenzas (280 vs. 140), likely have something to do with it. What's more, the prototype Stoptech brake system had been optimized only on paper for this application and hadn't yet undergone real-world development by the company's engineers — a process that we know from experience will shorten the car's single-stop distance.

Turning
Limited grip again defines the car's character in our handling tests. Here, however, it matches or exceeds the numbers produced by the stock coupe. Charging through the slalom cones at 68.9 mph, the RMR-tuned coupe proves a bit softer around the edges than its stock Track package counterpart, which is barely quicker at 69.0 mph.

Lateral grip is better, however, at 0.90g vs. the stock car's performance of 0.87g. This is due in part to the car's increased roll stiffness and increased receptiveness to throttle input. Its adjustable antiroll bars were set on full stiff front and rear for our test, and decreasing the front bar's stiffness might further improve this skid pad number.

This suspension performance comes thanks to the hardware provided by KW Suspensions, a German aftermarket suspension company with the testing resources to produce realistically streetable suspensions that still offer a performance and aesthetic improvement. For example, KW makes the adjustable suspension that comes stock on the Mercedes-Benz CLK63 AMG Black Series.

On the Road
Drive the RMR-tuned Genesis Coupe around for a few days and you'll realize that it rides more like a factory-tuned performance sedan than an aftermarket-tuned coupe. First, it's comfortable. This is a car that anyone could drive every day. Despite being at least an inch lower than stock, there's nothing about its ride quality that is even mildly disagreeable. There's ample compression travel to soak up the real world's irregularities, while the handling doesn't suffer despite not-so-sticky tires. Give this car some real rubber and there's likely a real monster hiding here.

This mild character means its edges aren't hard, so sensing its limits isn't as easy as it would be with more aggressive tires and suspension, but we think that's all right. The RMR coupe looks incredible and it works well. And for 90 percent of enthusiasts, this will be enough.

Although the brakes are prototype pieces which didn't wow us in a single-stop test, they still offer increased heat capacity and excellent pedal feel. We drove the car harder than we should have down our favorite mountain road — a 10-mile run that drops 3,000 vertical feet — and experienced zero fade.

Our only complaint is one that likely won't matter on a car with a stock final-drive ratio. Cruising at 2,750 rpm in 6th gear, which just happens to be freeway speed in Southern California, the RMR exhaust will drone your eardrums into numbness in about 30 seconds. Luckily, the taller final drive of the stock 3.8-liter V6 manual-transmission car drops the engine rpm during cruising just out of this resonance range.

Build Your Own
Assuming you start with a base model Genesis Coupe that starts at $25,000, you could duplicate the 2010 Hyundai Genesis Coupe by Rhys Millen Racing for almost exactly $40,000, including the $750 destination fee. Of course, $5,790 of the additional cost comes from the Stoptech brakes, and this is a tough sell when you can have the Track package car with its Brembo brakes, limited-slip differential and 19-inch wheels for $29,500 to start.

But that won't get you the stellar suspension, which makes this car what it is: comfortable, well mannered and unlikely. We'll take ours in Tsukuba Red.

The manufacturer provided Edmunds this vehicle for the purposes of evaluation.