The autobahn elite are territorial creatures. Storming the roads around Bottrop, Germany, squadrons of Brabus-equipped Mercedes terrorize the commoners. Dingolfing is overrun with MTM Audis, and Pfaffenhausen is infested with Ruf Porsches. These predators jealously guard their space, dispatching trespassers with extreme prejudice.
In BMW's camp, AC Schnitzer rules the area surrounding Aachen, and Racing Dynamics does the same in Dusseldorf. But, between the pair, which has the rights to the far left lane? Which stops quicker, corners harder and generally rules the pavement? Rather than hop on a plane across the Atlantic for a comparo, we gathered a pair of locally tuned E46 BMWs and headed off to Buttonwillow Raceway in central California. In one corner, wearing Arctic Silver paint, was AC Schnitzer's S3, and in the other corner, wearing Jet Black ink, was Racing Dynamic's K25 car. We didn't tell the respective tuners they would be squaring off against each other--duking it out on Buttonwillow's west loop, tearing through the 1/4 mile and slamming on the binders till the fluid boiled over--because every time we do one of these comparisons, someone invariably cheats (that's just the nature of the business; everyone cheats). The trick is not getting caught. The hell with that noise, though; we kept the field even through deception.
There are more than a dozen tuners which can take a base E46 to stratospheric performance levels (quite a few are actually based in North America). Of course, you could just buy a new M3 and be done with it, but where's the fun in that? Which program is right for you depends on what type of driving you do and, of course, how much money you want to spend. But look, before running off and modifying your ride, learn how to drive it in stock form. The E46 is an amazingly good chassis right out of the box. Get your ass to a driving school and familiarize yourself with the car before giving it a sharper edge--otherwise you're likely to just cut yourself.
AC Schnitzer has done for BMW cars what Hugo Boss did for men's attire. High profile, fast, exclusive, expensive--it's a given that someone driving a fully rigged ACS BMW is making serious bank. Ask any kid going to USC living on a $10k/month allowance what AC Schnitzer is and chances are he can recite the part numbers. The stuff is so desirable you can find cheap knock-offs just about everywhere. But ACS is more than just a fashion statement--it cut its teeth in Germany's ultra-competitive touring car circuit. ACS has been in the business for decades, earning its reputation through deeds, not words.
The S3 (short for Silhouette 3), was designed to mirror the aggressive lines of a race car. The vehicle on these pages was based on a 328i and features ACS sportswear, including a front and rear spoiler, side skirts, wing and sport mirrors. The stuff is manufactured from tough PUR-RIM with extra material around the stressed points, and the fit is impeccable. The running gear is ACS's signature Type III alloys, measuring 8.5x19, and are shod with Dunlop SP 9000 rubber sized at 235/35ZR-19.
The suspension is ACS's own recipe developed on the Nuerburgring and autobahn, consisting of springs, shocks and thicker, adjustable anti-roll bars.
The 2.8-liter engine was left alone save for a cat-back stainless-steel sport exhaust--BMW's factory numbers rate engine output at 193 bhp at 5500 rpm with 206 lb-ft of twist at 3500.
The cabin was custom-covered to CEC's own design, and its logo has been stamped into key places. Two-tone Nappa hides cover the front and rear seats, door panels and assorted surfaces. The Victor steering wheel features the same treatment, and the shiftknob, handbrake and foot pedals have been carved from aluminum. Though not visible, ACS's short-shift kit reduces shift throws some 30 percent.
Racing Dynamics has been making BMWs go faster for more than two decades. With Federico Pavoncelli at the helm, Racing Dynamics provides a unique blend of cutting-edge Italian style and hard-core German technology. The end results are well engineered, powerful and very striking.
Racing Dynamic's R25 is based on the entry level 323i and wears RD's togs, including a front spoiler (it replaces the entire bumper) and rear apron (bumper replacement), side skirts and sport mirrors, all wrought from PUR-RIM. RD 2 wheels measure 8.5x19-in. in front and 9x19 out back, and are wrapped with Pirelli P7000 tires sized 235/35R-19 and 265/30R-19, respectively.
The underpinnings have been massaged with RD's own springs and sport dampers, with sizable anti-roll bars (27/24mm) at each end. For extra rigidity, the R25 includes strut braces fore and aft that tie the points together.
The pronounced front airdam scoops feed RD's big brakes, based on four-piston calipers that grip 320mm cross-drilled rotors. The rear rotors are also drilled, and the rubber brake lines have been replaced with more rigid, braided stainless-steel units.
RD's progressive motor program includes sport camshafts and revised engine management software. The intake has been slightly modified for better breathing, and the exhaust includes RD's stainless-steel system. The 2.5-liter motor has been re-covered with RD's carbon-fiber pieces. RD's engine program raises horsepower from 170 at 5500 rpm to 192 at 6400 rpm, though at a loss of 3 lb-ft of torque.
The interior was treated with RD's aluminum pedals, handbrake lever and custom embroidered floor mats. The shiftknob is fabricated from Teflon(TM) and features the RD crest.
Faced with a wide-open track and full tanks of fuel, we set forth determined to find out which car had the edge.
The Easy Part
Despite its shorter stroke (75.0mm vs. 84.0mm) and thus less displacement, the R25 car was faster both in the dash to 60 mph and the 1/4-mile. The R25 covered the 0-to-60-mph distance in 7.3 sec., whereas the S3 did it in 7.53 sec. In the 1/4 mile, the R25 clocked a 15.50 sec. with a terminal speed of 90.3 mph, while the S3 did a 15.58 sec. at 90.9 mph. Anyone with internet access will instantly realize these times are slower than what's posted on BMW's website. The 328i is supposed to clock a 6.6-sec. 0-to-60-mph time and the 323i a 7.1. It would be easy to blame slipping clutches and, in truth, they were both starting to fail, but we still managed to get two good runs in a piece. Those monster 19-in. wheels were most likely the culprit, which is like running the 40-yd dash in Doc Martens--stylish, but not the ideal running shoes, then again it could have been the 85* weather.
The big binders on the R25 paid off immediately, providing quicker stops all around. The R25 went from 60 to 0 mph in 114 ft, while the S3 did it in 120 ft. After repeated stops, the R25 showed no signs of fade, whereas the S3 binders began to lose their bite. No big surprises there--bigger is better (in this case anyway).
On The Track
In stock form, the E46 chassis is fairly neutral with a slight bit of understeer at upper limit. The RD and ACS suspensions dial out that speed-scrubbing understeer with larger sway bars, a lower stance and firmer spring and damper rates. At the limit, both cars were more neutral and the throttle could be used to bring the tail around.
In terms of ride quality, the R25 was slightly firmer and seemed to do a better job over high-speed irregularities in the pavement. The ACS car on the other hand, was more comfortable when we had to run to the parts store to fetch a new water hose. Both cars were very, very close in overall ride quality, however, providing a good compromise between comfort and firmness. Ultimately, the upper hand went to the R25 because of its bigger brakes. The damn things were absolutely fade-proof and let us dig deeper into the corners. In fairness, ACS has its own big brake kit--too bad this car didn't have them.
The R25 also had the edge in power, not much mind you, but enough to make it more entertaining, especially when the cams came into play. The R25 consistently made it around Buttonwillow's west loop faster than the S3 (it could have been the big brakes). The R25 had a better exhaust note, too--a bit more rasp--whereas the S3 was damn near silent, maybe a tad deeper than stock.
Styling
Both tuners had done their homework in the wind tunnel and the autobahn, where extended high speeds test the limits of every wing, airdam and valance affixed to the cars. At 140 mph, both cars exhibited rock-solid aerodynamic stability. Standing side-by-side, the ACS car garnered more looks. It could have been because of its gorgeous silver paint, but I think there is more behind its allure. The ACS styling just looks right, better even than BMW's own M line of body styling (this is only an opinion), providing a great blend of aggression and understatement (is that possible?) that begs a second look. And ACS's fit and finish is second to none--just ask any body man who works with the stuff. It is perfect. Period.
Both cars were tarted up with pedal kits that made heel-and-toe driving easier. While the nylon shiftknob on the R25 was a nice piece, the ACS short shifter rules--it doesn't matter what it is attached to. The leather work in the ACS was beautifully done and in regards to color coordination, perfect. The contours of the ACS steering wheel was great, too, providing just enough meat where it was needed most.
And the Winner Is...
In a perfect world we would have left the track with a clear idea which tuner had the upper edge. In a perfect world. Truth is, no such place exists and many factors must be considered before signing on for either program. If we were going to need a car for weekend club racing and occasional canyon carving forays, the R25 would be the first choice. Moreover, Racing Dynamics just opened a sizable operation in Southern California with the intention of offering full motor conversions through selected BMW dealers. If you're looking for powerful, normally aspirated performance Racing Dynamics is the right tuner. However, for cutting-edge style, ACS still has the edge.
Claus Ettensberger Corp.
16200 S. Figueroa St. Gardena, CA 90248
(800) 766-0064
www.cecwheels.com
Racing Dynamics
4750 Eisenhower Ave
Alexandria, VA
(800) 296-8850
www.racdyn-usa.com