When you drive fast cars for a living, it's difficult not to be blasé when a tuner claims that his latest car is the best thing since sliced bread. But when a car sets your pulse racing just like it did when you were a newbie, you know you're on to something special.That happened when I drove Nowack's 5.7-liter M5. The claimed 628 hp and 457 lb-ft of torque are impressive enough, but this engine really can set the hair on the back of your neck tingling.
The enlarged V10 starts with a deeper, angrier bark. Blip the throttle and you can feel the engine rock on its mounts, the distinctive offbeat V10 howling before it settles into a steady, grumbling idle that threatens imminent thunder and lightning.
At town speeds it's as docile as you could wish for. In fact, it's better than standard since the beefier torque curve confers a "waftability" to its low-speed behavior. While on the one hand it responds more crisply, and revs even higher than stock at the top end, the more under-square dimensions help its newfound torque-rich character deliver a creamy smoothness of delivery that catches you unawares.
Top-end performance is awesome. It punches hard through the gears, and that uncorked V10 wail gives it the keen soundtrack of a Lamborghini Gallardo. It's this, and the way it pulls with renewed vigor between 7000 and 8200 rpm in fourth and fifth gears, that makes it feel so special.
Nail the throttle in sixth gear and copious torque available at 4500 rpm makes the motor as keen as ever. Where the standard engine is fast running out of answers, you now feel real acceleration. Drop a gear and your efforts are answered by a solid push in the back as the rev counter needle rushes into the red.
The much greater torque in the first half of the rev band changes the engine's character completely. Rather than the standard V10's aggressive high-rev behavior standing out in comparison to its relatively lethargic bottom end, you feel significant thrust all the way from idle to cutout. The smooth and progressive delivery disguises the car's true pace, until you look at the speedometer and the rate at which autobahn traffic is so easily caught and passed.
If you really want to sample the animal side of this engine, you just have to gun hard it in second gear with DSC disabled. The wave of torque breaks the big tires free in an instant, and the clever M differential coupled to a deft bit of steering and throttle craft will ensure a long and satisfying drift through third gear-and into fourth if you so wish.
The counterpoint to all this is the fact that in normal driving less revs are required to keep pace with the traffic flow, so the potential for better fuel economy is also there. With the bottom end now filled in nicely, the V10 becomes the consummate all-rounder.
At the root of this behavior is the old adage that there is no substitute for cubic inches, except more cubic inches.
"BMW's V10 is very powerful in standard form, but it lacks low-end torque," Oliver Nowack explains. "It needs high revs to really get cooking with gas, and because the M5 and M6 are heavy cars, the perceived time it takes for the engine to get on cam is quite long."
Where the standard engine has 4,999cc from a bore and stroke of 92.0x75.2mm, the 5.7 has 5,679cc from 94.2x84.0mm. "This is the only way to get 5.7 liters," Nowack says. "There is no space for larger diameter pistons or a longer-stroke crank in the crankcase. It is absolutely at the limit."
The new steel billet crank is another Cosworth masterpiece; the forged alloy pistons are from the renowned Austrian race piston maker, Pankl, and save 35 grams each. The valve pockets in their crowns are the same shape as stock, but enlarged to match the bigger valves. The race-grade, H-section connecting rods come from Auto Verdi in Sweden, save a quarter pound per rod, or 2.5 pounds for the set of 10. They cost €450 each-$660.
As for the camshafts: "Normally you can put a wilder cam in a larger capacity motor," Nowack explains. "But today's clients do most of their driving between 2500 and 5500 rpm, so I went for a cam profile with a shorter duration, lower lift and less overlap. The result is more torque, better fuel economy and full functioning of the VANOS system."
The fuel injectors are stock and the fuel rails pressurized to 7.0 bar by the two stock pumps. It turned out that the stock injectors and fuel system had enough headroom and work just fine. On the induction side, high efficiency air cleaners in the modified airbox feed ram air into throttle bodies bored from 50 to 52mm. The dirty side of the engine wears a bespoke exhaust system with Nowack headers, 200-cell cats, free-flow rear silencers and 68mm diameter pipework.
Despite the larger capacity and greater output, aside from some special coolant for the radiator, testing revealed that no extra oil cooler was needed. A twin-plate clutch with semi-race organic lining takes power to the SMG gearbox, whose control protocols were re-mapped to work with the new power and torque curves.
When a car this size knocks on the door of 200 mph, it takes a lot of stopping power. Nowack use the largest Brembo brakes that will fit the front axle: massive 405mm cross-drilled and vented rotors with eight-pot calipers and high-performance pads. As most of the braking is done by the fronts, the factory rear brakes were adequate. All the brake lines were replaced with stainless steel braided hoses, and DOT 5 fluid was pumped into the system.
To harness the extra power, H&R supplied new race-style, height-adjustable coilovers. Since the factory damping is electronically controlled, these units have an added refinement in the form of an auxiliary electronics pack that interfaces with the ECU to make it think all is normal and prevent it from throwing up a fault code.
The M5 already has a front strut brace, so when you open the hood, it all looks normal. However, Nowack uses one with slightly larger diameter tubing, while under the car the stock anti-roll bars have been replaced by three-position adjustable bars, 2mm larger in diameter.
Nowack's distinctive alloy wheels are 9x20 and 10x20 with 255/30 and 285/25 tires front to rear. The Avon ZZ3s make for an unusual choice of rubber, but after testing a variety of competing tires, Nowack concluded that these strike the best balance between performance and comfort with this suspension.
Changes in the cabin are minimal, the most salient feature being the lightweight Recaro seats. The recalibrated speedo now reads out to 360km/h and the rev counter electronics were modified to take the higher rev limit into account.
While they can be fun when you're in the right mood, high-revving engines that lack low-end torque can end up being tiresome for everyday use. The Nowack 5.7 cures that problem by giving the M5 both copious low-end grunt as well as its ballistic, racecar-grade top end.
I was so impressed that I want more-but not actually more power. You see, I'm having this recurring dream about using the 5.7 in a mid-engine supercar weighing less than 3,000 pounds.
Nowack M5 5.7
Longitudinal front engine, rear-wheel drive
5.7-liter V10, dohc, 40-valve. Cosworth steel billet crankshaft, Pankl forged pistons, Auto Verdi connecting rods, ARP fasteners, custom camshafts, enlarged valves, modified airbox with high-flow filters, Nowak sport headers, 200-cell cats and exhaust, ECU remap
Seven-speed SMG with twin plate clutch
H&R race-style coilovers, custom front strut brace, adjustable anti-roll bars
Eight-piston Brembo calipers with 405mm cross-drilled rotors (f), OEM assemblies (r), braided stainless lines
Wheels and Tires
Nowak alloys, 9x20 (f), 10x20 (r)
Avon ZZ3, 255/30 (f), 285/25 (r)
Recaro sport seats
Peak Power: 628 hp @ 8000 rpm
Peak Torque: 620 lb-ft @ 4500 rpm
0-62 mph: 4.1 sec.
Top Speed: 186 mph
Large displacement, naturally aspirated motors and their governing electronics are Oliver Nowack's speciality. Although his tuning activities had been bubbling away in the background before then, it was only in 2000, when he launched his treatment for the E39 M5, that the world sat up and took notice.
While the engine retained its stock displacement, Nowack's work on the induction, cylinder heads and exhaust extracted 500 hp from the M-Power V8, a conversion that became a legend in its own time.
He sold more than 20, and an early car that went to Singapore is still being used daily by its wealthy owner, who has a big supercar collection that includes two McLaren F1s and the first RHD carbon-finish Pagani Zonda. Even with all this exotica, he says the Nowack M5 is his favorite.
In 2005, Nowack Tuning dropped off the radar. The reason was a chance involvement in motorsport that gave Nowack the opportunity to build race engines for a German VLN Championship race team. The Z Racing Team was looking for a BMW race engine specialist, and it was something Nowack had always wanted to do.
"Race engine building is harder as you have a firm deadline to meet, and no time for things like problems with component suppliers," he says. "Either you're ready in time to race or not, and you win or you don't."
While race activities didn't take him entirely out of the tuning scene, the commitment certainly took him a big step away from it. The counterpoint was that some of the engineering techniques learned during the course of his race preparation would be filed away for later use.
Nowack returned to street tuning after the 2008 racing season. In April 2009, he changed his company's name from Nowack Auto + Sport to Nowack Motors, to better reflect his engineering speciality. Since then, he has perfected a small number of large-displacement engine developments, notably the 4.4-liter E92 M3 and E60 M5.
"Things have changed a lot in the last decade," he says. "Back in 1998, an M5 cost 85,000 euros, but today you pay that much for an M3. Development work has also become more expensive because on-board systems are more sophisticated.
"As a tuner, you spend more money now for the same solution you had with the previous generation car. So you can only afford to do two or three projects a year now, and can't earn the same money as 10 years ago." -IK