We visited Manhart Racing on the outskirts of Wuppertal in northern Germany to test a couple of its outlandish M3 conversions. On this occasion we'll be looking at the MH3 CSL V10 Clubsport, which - as the name would suggest - squeezes the E60 M5 V10 engine into a replica of the E46 M3 CSL, along with a phalanx of lightweight and reinforcing modifications to justify its Clubsport moniker.
The second car, the MH3 5.0V8 (an E30 M3 with E39 M5 power), will appear in a future edition of european car magazine...
When the CSL first arrived in 2004, it was lauded for it's sonic qualities - the carbon air box piped a racecar straight-six snarl into the cabin and sounded plain awesome. While the barely silenced S85 V10 in this "CSL" sports a similar setup with its beautifully finished carbon air box, the balance of sound has shifted rearwards. The free-breathing exhaust, sport cats and titanium rear muffler can be thanked for that.
The net result is an E46 fizzing with aggression that erupts like a volcano every time you push the throttle. The noise fills every inch of road tunnels with sonic shockwaves that bounce back through the windows (which you'll have instinctively opened before entering the tunnel). It makes the car incredibly entertaining to drive but we have to confess it would be marginal for daily use.
Of course, it's not just the sound that morphs the character of this M3 from balanced sports GT to hardcore weapon. The V10 transplant transforms how it accelerates, thanks to 550hp motivating around 3000 lb (compared to the 4000 lb E60 M5 with 500bhp).
Hooked up to the donor M5's seven-speed SMG transmission, you simply plant the throttle and snatch the right paddle before clipping the 8500rpm rev limiter in each gear. You're then treated to a level of accelerative intensity few E46 drivers would recognize. However, it's tempered by the SMG itself, which may have been state of the art in '05, but its clunky low-speed response and jerky shifts is less acceptable in a world of dual-clutch finesse.
Of course, the nature of the S85 V10 means it needs to be halfway around the rev counter before it really starts to fly, but the high revving character suits the lightweight E46 chassis perfectly.
Thanks to modern engine technology, the motor is docile and tractable at low revs, just as in the M5, but in this application the top-end buzz is magnified into an intoxicating lunge for the horizon that makes you laugh out loud. It's ridiculously fast, no matter how you look at it.
How fast? Without timing equipment on-hand we resorted to the stats. At around 400hp/ton, the power-to-weight ratio puts you in the same ballpark as the Ferrari 458 or Gallardo Superleggera. And while it doesn't feel quite as rapid as those supercars, we'd suggest it's not far off.
Remarkably, the V10 didn't add a bunch of weight to the M3, its lightweight construction apparently only adding an extra 90 lb, which was countered by the various weight reducing steps of the MHR Clubsport package.
This included forged OZ Racing wheels plus a carbon fiber vented hood and trunk. It has CSL carbon door cards and dash inserts, gaining a carbon center console to keep the M3 light on its feet. Fixed leather/alcantara CSL race seats hold you firmly in place while an aluminum rollcage provides a level of protection. All this means the overall weight is slightly higher than a stock CSL, with a small shift in its distribution.
Predictably, the biggest enemy is traction from a standing start - or lack thereof. The tires struggle to gain purchase on the road surface, the traction control light flickering in unison with throttle opening and engine speed.
Disabling the traction control helps a little because you can balance wheelspin against road speed. But with good weight distribution, road tires and the 3000 lb curb weight, traffic light grands prix are never going to be the car's forte. But hit third gear and you experience the full "Millennium Falcon" blurred background effect.
That's something we experienced several times during our drive to the photo location, thanks to a stretch of autobahn interspersed with country roads. It generated a smile every mile and thumbs up from several 'bikers, presumably surprised they weren't able to reel us in as we hit the first stretch of open road.
Country roads reveal the extra authority brought by the MHR/KW Clubsport coilover suspension package: It's a tough-riding son-of-a-gun. Body roll is non-existent, turn-in is instantaneous, and grip is prodigious. Every body action is checked in the first damper movement, and the car feels granite rigid as a result. Unfortunately, traveling at regular speeds is borderline uncomfortable, but with increased velocity the uncompromising springs smooth out and find their natural frequency. Of course, that's not at a speed compatible with other traffic...
Such is the grip and control of the MH3 that it's a thrilling drive but one that needs empty roads to explore, or a certain 14-mile stretch of racetrack 80 miles south of Manhart's Wuppertal HQ by the name of "Nürburgring".
You'd be forgiven, therefore, for assuming the MH3 is a handful, but extinguishing the driver aids (after swallowing a brave pill) reveals a chassis as beautifully balanced and controllable as the stock CSL, although the extra power makes it easier to dictate cornering attitude.
The steering is stock M3, so it's quick and accurate without being nervous, but not brimming with feel. It's probably the only shortcoming in an otherwise well honed package; no wonder Manhart CEO Christoph Erfurt said it's his favorite car for driving...
The standard CSL brakes were never suitable for track work with the 360hp straight-six, so they weren't going to contain the thrust of the 550hp V10. MHR's solution was a set of Mov'It rotors and multi-piston calipers; producing a left pedal that inspires confidence thanks to its massive and progressive stopping power.
The E46 M3 CSL is held in high esteem by enthusiasts, and subjecting such an icon to this level of modification could be a precarious business, risking criticism that you ruined - rather than enhanced - the original car. However, the MH3 CSL V10 Clubsport from Manhart Racing has taken the CSL recipe, added a dose of spice, but kept the flavor intact.
2004 BMW M3
Engine 5.0L V10 DOHC with Manhart Racing software, K&N Typhoon intakes, Manhart carbon fiber air box, exhaust headers and titanium muffler with tips, Hartge downpipes and sport cats
Drivetrain seven-speed SMG semi-automatic transmission, custom driveshaft, Manhart shifting software
Brakes 380mm cross-drilled Porsche Motorsport rotors with six-piston AMG calipers f, 345mm CSL rear brakes
Suspension Manhart/KW Clubsport coilovers, lowered 55mm f, 40mm r, adjustable sway bars
Wheels & Tires 19x9.5" f, 19x10.5" r OZ Racing Ultraleggera HLT wheels, 235/35 R19 f, 285/30 R19 r Toyo Proxes T1 Sport tires
Exterior CSL-style front spoiler with carbon lips, trunk and diffuser, Hartge carbon vented hood, Cup-style mirrors
Interior Leather and alcantara Porsche 996 GT3 seats, CSL carbon door panels and dash trim, carbon fiber center console, Manhart 360km/h speedometer, LCD information display in central air vent, Wiechers bolt-in rollcage