What's the difference between 650 and 700hp? Does your head snap back that much harder, or does the g-force push you into the seat that much deeper? Does the scenery blur more? And does it matter when 650hp is already enough to lay waste to most challengers?
In the supercharged M3 arms race, it does matter because 650hp is where you'll find the stage 2 kits from ESS Tuning and VF Engineering maxing out, with G-Power's rated at 610hp. So getting more power usually requires a stage 3 kit with different internals to handle the higher boost.
With that in mind, we were naturally intrigued when Active Autowerke told us about its new Generation 2 Level 3 supercharger kit developing 700hp on stock internals. We decided to investigate this further.
Most of Active's competitors limit stage 2 boost to around 8psi, including the company's own 640hp Level 2 kit. And while it may seem unfair to compare Active's (Level) stage 3 to another company's stage 2 kits, the key here is retaining the stock internals.
Level 3 is apparently rated at 9psi at redline, with an extra 0.5psi spike just before the throttle closes, giving a peak of 9.5psi.
Karl Hugh, Active's Technical Director, explained how they were able to control boost by careful manipulation of the S65 engine's Vanos variable timing system, controlling cylinder pressures, valve overlap and scavenging.
Hugh also discussed how the new Rotrex C38-92 trim supercharger, which is the basis for the Generation 2 kits (replacing the previous gen HKS GTS 8555), maximizes the scavenging. He chose the Rotrex because it made more power and had better adiabatic efficiency.
To lower the engine's intake temperatures, a front-mounted air-to-air intercooler is fitted. It further has the benefit of methanol injection, which is distilled 50/50 with water.
The E92 M3 shown here has become known as "Blitzkrieg" after it got its name from Active's enthusiastic Facebook fans. It's the company's showcase for the Generation 2 Level 3 supercharger system. It's also home to a prototype big brake kit the Active is producing, along with their own 20" ACW wheels.
The car is also covered in a Skinz Wrap vinyl wrap with a blueprint graphic created by Active's in-house designer for maximum impact.
Finally, there's a Mode Carbon front spoiler and BMW M Performance trunk spoiler plus an Auto Carbon rear diffuser.
You can hear the faint whine of the supercharger as the revs climb, but it's not intrusive or any noisier than other systems on the market.
At regular driving speeds, the supercharged engine feels smooth, neither jerking nor snatching when getting on or off the throttle.
The supercharger comes on early, and the extra grunt overcomes the S65's lack of low-end torque. Active claims the torque peaks at 380 lb-ft to the wheels, (46% more than stock) just before 8000rpm. Yet 80% of that is available from 3300rpm. The horsepower peaks at 8200rpm, registering 590hp at the wheels.
So when you push the right pedal harder, power builds with rabid ferocity. There are demons being exorcised every time you run to redline, screaming through Active's stainless exhaust system, which features an X-pipe and high-flow cats. You can't feel any hesitation or let up in the power curve, it's just a building crescendo of annihilating force.
Whether or not it's faster than a 650hp stage 2 set up is hard to say without a head-to-head race. It's like trying to tell the difference between taking a blow to the head from a 5 lb and an 8 lb sledgehammer.
I will say that I've never driven a supercharged M3 that accelerates from 30-150mph at the rate of this one. Nor have I driven one as explosive, that races for the redline as quickly as Active's Blitzkrieg.
Even when approaching 150mph, the rate of acceleration only tapered off slightly as the engine began to fight wind resistance. There was plenty left but we ran out of road.
An amazing thing happens when you stand on the prototype brakes. The gargantuan 12-piston front calipers squeeze 405mm (15.9") slotted rotors, with an eight-piston/15" set up in the rear. The forged aluminum calipers are mounted on CNC-machined steel brackets for maximum rigidity. The front calipers also use six pads per corner, with the rears using four, for a total of 20 brake pads. Consider that when it's time for maintenance!
Predictably, these giant stoppers grab instantly, and with such force you'd think the car was going to flip end-over-end. They didn't show any signs of fade, even after three stops from 150mph.
Active worked closely with the brake supplier to find the right brake bias, switching from six to eight-piston on the rear to achieve the overall balance they wanted.
In addition to the ACW wheels (20x9" front, 20x10" rear) and Nitto Invo tires (255/30, 295/25 respectively), Blitzkrieg rides on JRZ Pro coilovers with external nitrogen canisters. The combination produces a firm ride with sharp turn-in response and hardly any body roll.
In the rapidly-evolving supercharged M3 segment, where we've seen incremental steps to greater power, Active's Gen 2 Level 3 kit looks and feels like it's set the benchmark for bolt-on power. Maybe we'll get to compare it to one of its competitors on the road or track to get a definitive impression of who rules the roost.
The second M3 in this article is owned by Active customer, Chris Ritter. It wears similar Skinz Wrap vinyl after he saw Blitzkrieg and had to have it.
The E36 is a reminder of Active's roots, harking back to when the company was first featured in this magazine in EC 5/97 with a trio of M3 turbos that instantly made everybody take notice.
The company has since moved away from turbos to more emission-friendly superchargers, but its expertise with the E36 chassis was on full display with the track-spec car featured here.
Active took this '99 five-speed and removed all the dead weight before welding in a four-point rollcage. It now weighs 2950 lb. Thanks to chassis reinforcement, you can feel every imperfection through the Sparco race seats, and hear every pebble thrown up by the sticky Nitto Invo tires.
Although street legal, it's probably not something you'd drive daily unless you need to get your adrenaline moving in the morning. It gives a raw driving experience, making modern cars feel like sensory deprivation tanks.
The engine is the familiar 3.2-liter S50, but it generates an extra 200hp thanks to Active's Stage 2+ C-38 Rotrex-based supercharger kit. It's supplemented by a custom 3.5" intake pipe and Schrick cams as well as Active ECU programming.
As before, the internals remain stock while the exhaust consists of Active headers and race system.
To maintain engine temps, it runs an oversized radiator and high-performance fan clutch. Oil is cooled by another Active radiator.
After you've tightened the harnesses, you push on a stiff race clutch that makes smooth starts challenging, requirinh throttle manipulation. Once underway, swapping gears required little effort, however, thanks to Active's short-throw shift kit.
With the car sitting as low as you dare on the street, and the tight suspension providing quick responses, the car felt like a 3/4-scale M3. It was the lightest 2950 lb car I've ever driven thanks to its lightning reactions. Shedding 200 lb and adding 200hp has given the car a respectable power-to-weight ratio.
Wind it out and you're bombarded by the unfiltered soundtrack of the race exhaust. And as the Rotrex C-38 instantaneously springs to action, it just doesn't quit. Maximum boost is set at 11psi, developing 450hp.
Fitted with Ground Control coilovers and Koni inserts, the turn-in is razor sharp and the car holds a tight line. Yet getting the tail loose only requires a stab of throttle to overwhelm the tires, then a dose of countersteer brings it back into line. That kind of balance and adjustability makes this E36 so entertaining.
Getting to sample two generations of M3, albeit two cars with completely different missions, gave us a great picture of how much things have changed, and yet stayed the same.
Obviously, the E92 Blitzkrieg is better in nearly every aspect but, as many have lamented, the bigger car has added weight and sacrificed steering feel. However, it's raised the bar for the supercharged M3 segment and boggles the mind with its ability. Yet I'll admit, the E36 M3 left me with a bigger grin!
2012 BMW M3
Engine 4.0-liter S65 V8 32v with Active Autowerke Gen 2 Level 3 supercharger system, X-pipe and high-flow catalytic converters, cat-back exhaust system
Drivetrain M-DCT seven-speed automatic transmission
Brakes Active Autowerke 12-piston calipers, 15.9" slotted rotors f, eight-piston, 15" r
Suspension JRZ Pro coilovers with external canisters
Wheels & Tires 20x9" f, 20x10" r Active Autowerke ACW-20 wheels, 255/30 R20 f, 295/25 R20 r Nitto Invo tires
Exterior Mode Carbon front spoiler, BMW M Performance trunk spoiler, Auto Carbon diffuser, Skinz Wrap vinyl wrap
Interior AEM Uego boost and oil pressure gauges in Macht Schnell pod
1999 BMW M3
Engine 3.2-liter S52, six-cylinder 24v with Active Autowerke Stage 2+ supercharger kit, Schrick cams, Active software, race headers and exhaust
Drivetrain five-speed manual transmission, Active clutch, lightweight flywheel, short-throw linkage
Brakes Active Autowerke four-piston calipers, 13.1" rotors, race pads f, stock r with race pads
Suspension Ground Control coilovers with Koni inserts, 28mm f, 17mm r adjustable anti-roll bars
Wheels & Tires 18x8.5" f, 18x9.5" r D-Force wheels, 235/40 f, 255/35 R18 r Nitto Invo tires
Exterior carbon fiber hood, Skinz Wrap vinyl wrap
Interior Sparco race seats, five-point harnesses, four-point rollcage