• Aug 22, 2006

BMW's turbocharged 335i is rated by the manufacturer at 300 HP and 300 lb-ft of torque at the crankshaft, which seemed a bit low to us considering the 255 HP rating of its naturally-aspirated brethren. Sure, the turbo system was designed to maximize the usable powerband instead of creating moonshot-like peak power, but a mere 17% bump in the power ratings just didn't compute.

Investigating the matter further, Automobile Magazine strapped down a 335i to a Dynojet chassis dyno. Such a device measures power at the rear wheels, and translation into crankshaft numbers requires that one account for drivetrain losses. Taking into account the loss of 15 healthier than the 330i.

So, what's up? Yes, the new SAE J1349 dyno standard is supposed to eliminate this sort of rating tomfoolery, but it's only accurate under one specified set of conditions. Dynometers, such as the Dynojet, attempt to correct the results back to a set of conditions, but they're slightly different than those used for J1349. That likely accounts for only a few percentage points of difference, though. More likely is that the Bimmer's engine management system, rather than simply establishing a limit for boost, is constantly attempting to maximize airflow while controlling detonation. Such a system cannot easily be corrected, and putting such a vehicle on a dyno under optimum conditions (usually with particularly cool ambient air temps) can yield results well in excess of the manufacturer's ratings, and this likely explains why the measured torque peak is disproportionate to the horsepower peak.

All this power - accessible at nearly any engine speed, judging by the broad torque curve - gives the 335i performance that nearly rivals that of the previous-gen M3, with the quarter-mile disappearing in 13.6 seconds and with a trap speed of 104 MPH. That sort of performance puts it in the running as Sleeper of the Year.

[Source: Automobile Magazine]



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  • 29 Comments
      • 8 Years Ago
      #9... why would Toyota do that? Manual Coupe 335i is as fast as Automatic IS350 sedan (0-60 in 5.1 secs)... They have only managed to rearch IS350, and it will cost you $6k more... lol.
      • 8 Years Ago
      LOL! #5 did you just compare a GTO to a BMW? Just because a car can go fast doesn't make it the Ultimate Driving Machine!
      • 8 Years Ago
      "BMW 335i:
      300HP? 300lb-ft? they made this more political than an "ultimate driving machine"...

      Subaru WRX STi:
      300-hp 2.5-liter DOHC intercooled, turbocharged boxer engine 300 lb-ft of torque at 4,000 rpm...

      Am I missing something here BMW fanboys?"

      Posted at 3:33PM on Aug 22nd 2006 by tomfoolery

      Yes, you are missing something. TURBO LAG!!

      The Subaru certainly isn't missing it, though.
      • 8 Years Ago
      BMW 335i:
      300HP? 300lb-ft? they made this more political than an "ultimate driving machine"...

      Subaru WRX STi:
      300-hp 2.5-liter DOHC intercooled, turbocharged boxer engine 300 lb-ft of torque at 4,000 rpm...

      Am I missing something here BMW fanboys?

      Let the flames begin
      • 8 Years Ago
      No doubt this engine can make more power than they advertise. They underrated it so as not to encroach on M3 numbers.

      Maybe when the new M3 comes out, they'll crank it up a little bit. If not, I'm sure the aftermarket will definitely be able to squeeze more power out of it very easily.
      • 8 Years Ago
      The simplest explanation for this is not fancy engine management (though that likely is responsible for more than a few ponies) but marketing. If BMW quoted the 335's power in the 340-350hp range, the $10,000 price premium for a 400hp M3 wouldn't make too much sense. Consumers tend to look to power numbers before anything else, and that small power gap would cause them to overlook the M3's other performance upgrades.

      That said, once the aftermarket for the 335i gets started, they should be very competitive with the M3 (in a straight line).
      • 8 Years Ago
      I wouldn't get too excited about the numbers until I see a regular Joe Schmoe buy one off the lot and dyno it. The car used here isn't a production model. It's a press model.
      • 8 Years Ago
      Re: Dr1v3r
      "Turbos are for cheaters. Boy that comment will get some noise."

      Yes, and torque is for fat people.
      And real men can produce 250hp with 1.3L displacement (Renesis motor)

      To each, their own. In most applications (not sure of this one), using a smaller motor with a turbo gets better fuel efficiency than a larger motor with the same power ratings.
      • 8 Years Ago
      Another trick from the Audi people who have been playing with turbos for years is to disconnect the battery for a while and let the engine ECU forget everything it's learned. Then when you power up again, it has to establish a new baseline. While it's doing that, you often see more boost/power as it explores the upper limits, than you will once it's learned those limits and dials in a safety margin.
      • 8 Years Ago
      settle a bet with a friend, what does bimmer mean?
      • 8 Years Ago
      So why is it that for 2007 Nissan will be putting out more than 300hp, naturally aspirated, in their 3.5 V6's? Which has been on Wards top 10 list since its inception....

      Turbos are for cheaters. Boy that comment will get some noise.
      • 8 Years Ago
      ...just smart enough to spell and write correctly.

      HKS SBC = turbo lag bye bye!

      Flame On!
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