Immediately off the dyno Car 1 felt fine on the street. In fact, a quick VBox test showed both cars netting similar, back-to-back 0-60 times when tested just around the corner. A few days later, EAS’ Steve Lee put it back on the dyno and ran it without selecting dyno mode. Expecting the car to cut fuel prematurely, it ripped 292 whp repeatedly. “We test a lot of these E46 M3s and I’ve never seen anything like this,” Steve said. Conclusion? Car 1 is fine, it’s just weird and hates the dyno.
Back to our comparison. According to EAS, 292 whp is normal for a lightly modified M3. Still, it’s 15 whp shy of Car 2. To confirm, we lined them up. In in an effort to take out driver error, we did a Third gear, side-by-side pull from 40 to 100 mph. Not surprising, Car 2 pulled over a solid car length each time.
Note: Therefore, with a 20-whp total gain over stock, one could argue Car 2 is at least a car length faster than it was bone stock.
So what can we conclude? While the test didn’t go as planned, the answer is these two seemingly identical cars don’t perform the same. In fact, with a 4.96-second pull from 35 to 95 mph during that one 292-whp dyno pull, Car 1’s acceleration—with new fluids and Evolve software—was spot-on when compared to Car 2’s 289-whp baseline run, which was about 15 whp shy of where it ended up with the ECU upgrade later.
It all adds up. Car 2—with 60K more miles and even top-heavier by 40 pounds—is significantly faster, which confirms my initial test-drive impressions.
EAS also reported Car 2 proved stronger than most other M3s tested on its dyno. Maybe it was broken in differently, or maybe the owner simply got lucky. Maybe he got a handpicked “lightweight” motor from BMW (an inside joke for you E36 guys).
307.0 whp @ 8000 rpm
239.6 lb-ft @ 4800 rpm
Max Power Gain:
5.0 whp @ 6750 rpm
Max Torque Gain:
4.0 lb-ft @ 6400 rpm
35-95 MPH Dyno Acceleration:
7500-8000 RPM Air/Fuel Ratio:
GruppeM two-piece carbon-fiber intake, GruppeM-spec K&N conical filter, installation hardware and MAF housing
Great engine dress-up, quality carbon construction
Expensive, some cutting involved
As expected from a GruppeM product, the quality is superb. Installation requires cutting the upper-back plastic portion of the back of the kidney grilles to fit the ram-air duct. It also opens up the intake tract for a theoretically improved ram-air effect at speed.
On the dyno, while the peak versus peak comparison yields only 1.5 whp, the curve does show a consistent torque gain of 3 lb-ft from 3300-7000 rpm, netting a peak 5 whp in the upper midrange.
With better fluids, plugs, an ECU upgrade and an intake, we’re up by a peak 20.2 whp and 13.3 lb-ft of torque at 7900 rpm. Not a bad afternoon. Track guys will like the fact this car now makes over 220 lb-ft from 2500 to 7000 rpm! Impressive for a 3.2-liter, especially since we haven’t messed with the exhaust.
What does that calculate out as in real-world acceleration? We took a before-and-after Third gear pull from 50-100 mph, using our PerformanceBox from VBox USA. Untouched, it clocked 9.1 seconds. Using the same stretch of road and starting point, with the exact same ambient, intake and coolant temperatures, it improved to 8.1 seconds. At this point we began to believe that the GruppeM’s “ram air” designation really does help at higher speed because, going by previous experience, we expected only a half-second improvement given the total gains shown on the dyno.
While we didn’t baseline the quarter-mile, we did try one after all other testing was done. On this one and only attempt, we clocked 13.2 @ 107.8 mph (at 1,400 feet of altitude that converts to 13.0 @ 109.5 mph at sea level). With a few more practice runs we firmly believe a 12-second pass is possible.
|Car 1 || Car 2|
|Wheels||VMR710, Matte Black||VMR718, Gunmetal|
|Tires||Continental EC DW|| Continental EC DW|
|Upgrades||software, intake|| software, intake|
|Horsepower||292 whp|| 307 whp|
|Torque||232 lb-ft|| 240 lb-ft|
|4.9 sec||4.7 sec|
|0-100 mph||12.1 sec||11.3 sec|
|1/4 mile||13.2 @ 107.7 mph|| 13.0 @ 109.5 mph|
|*corrected to sea level, launch mode used|