2007 BMW 335i Coupé
In the Name of Science, Seven Thousand RPM
Testing the Dynolicious software with a BMW 335i.
Words: Peter Orosz | Pictures: Gergely “AlieN” Antal
It is when you approach six thousand RPM that the quicksilver rasp enveloping the tight cabin takes on the urgent menace of something not quite meant for public roads. As the tach shoots for seven thousand, your muscles tighten for the robotized upshift, chief amongst them the tensors tympani in your middle ears.
Their function is to pull on the malleus, the largest of the ossicles in the middle ear. The malleus in turn tenses the tympanic membrane, protecting the auditory system from extreme amplitudes of noise. Which is exactly what BMW’s N54 engine produces in copious amounts at high revs.
The example at hand powers a 335i coupé and we are on a mostly deserted stretch of blacktop, making speed runs for science.
Clenched in my white-gray fingers is an iPhone 3G and I am about to have a 180-pound hairless monkey land on my sternum.
I have never before sat in the 335i, a car considered by many to be on par with the E46 M3, which makes the greatest noise this side of Emilia-Romagna. The performance figures are within a few percent: the M3 has 333 horsepower to propel 3,460 pounds to 60 mph in 5.2 seconds, while the 335i needs only 200 milliseconds less to do the same to its 3,527 pounds with 306 hp from its twin-turbo six.
Heavy, yes, but this thing will outrun a Lamborghini Miura.
Of said numbers, we need the weight. The rest we measure with our roadside dyno outfit: a pair of hands—mine—and a telephone. It is an iPhone 3G running Dynolicious, a piece of software that uses the phone’s accelerometer to record performance data. I hold it steady, press reset, then try to hold on as Handras, the car’s slightly edgy owner, drops the clutch. Or whatever passes for a clutch in a modern Bimmer with computers wedged in between your senses and the mechanicals.
One g of deceleration sounds barely more than bouncing up against a wall, especially when compared to the g-load of Formula One drivers and fighter pilots, yet the human body is quite unable to treat it a normal. The inner ear has evolved to treat one g coming from the direction of your feet as dandy. When said acceleration comes not at your soles but at your clavicles, your vestibular organ is visibly distressed.
A cushion of electronic music keeps us giddy in the cool August night as we clamber out of the car to look at the results. When you consider that the measurements were taken with a telephone instead of specialized equipment, the results are all the more remarkable. Both acceleration and deceleration figures are spot on with their official counterparts:
Those who have driven it say the N54 feels naturally aspirated. This is due to the fact that it uses two small turbos with the pressure dialed all the way down to 5.8 psi. This does get rid of the turbo lag but does not get rid of a BMW straight six’s unique selling proposition: that noise.
That noise between six and seven thousand rpm.
Amateur science has never been such fun.
∞ Published on Tuesday, August 12th, 2008