Friday, April 24, 2009

The S54 is No More

I don't have much good news to post about training or my knee so I'll continue to post more M Coupe lore that I have been saving up.

It's cliche, but the S54 engine truly is the heart of the M Coupe. Engines over 300 horse power are a dime a dozen these days, but it's how those horses are delivered that make the race bread S54 stand out. It is not a tuned up production-relabeled-performance motor that occupies the underhoods of most marque's performance divisions. It is a purebred racing motor that was adapted for street legal service. This is evident from the individual cylinder throttle bodies on top to the stock titanium headers below. It revs smoother than a jet engine, with the tach needle being the only clue that 8000 rpm is rapidly approaching. This is rooted in the fundamental advantage of an inline six cylinder platform. Straight sixes are in perfect primary and secondary balance requiring no balancing shaft or harmonic balancing. Cylinder 1 opposes 6, 2 opposes 4, and so on. Inline 4's, V6's, V8's, V10's and V12's would all destroy themselves if it weren't for complicated internal mechanics to counteract the varying directional loads placed on the crank shaft. Add turbos, superchargers, and funky tuning to the mix and you end up with a torque curve that looks similar to last week's stock market.

The S54



Individual Throttle Bodies


The Perfectly Balanced Inline 6


Sadly, 2008 was the last year for the S54. Here's an excerpt from Jalopnik.com that summarizes the virtues of the S54 and its demise:

While the aesthetes in us are relieved by the 2010 BMW Z4’s lack of fish-faced ugliness, the drivers in us are a bit worried. Only available as a folding hardtop, we’re a bit concerned about the added weight and lack of a sexy coupe, but mostly, we’re disturbed by the absence the S54B32. Though the Z4 will use inline-six engines, ranging from a 2.5-litre 201bhp to a 302bhp twin-turbo 3.0-litre, it won’t be getting the 343 HP naturally aspirated 3.2-liter unit. That means the old Z4, which has now gone out of production, was the last production BMW to use the legendary powerplant.

The S54B32 engine is an evolution of the S52B32 engine of the E36 M3. It makes 343 HP at 7,900 RPM, 269 Lb-Ft of the creamiest torque you’ll ever use at 4,900 RPM and revs all the way to 8,000 RPM. It was used in the E46 M3, 2001 and 2002 Z3 M Roadster and Z3 M Coupe, the Z4 M Roadster and Coupe and even the Wiesmann Roadster.

The reasons for its popularity are two-fold: its specific power output exceeds 100 HP/liter without the aid of forced induction and its torque curve is fat, smooth and gap-free across the rev range. The S54B32 revs quickly, makes power everywhere, sounds like nothing else on the planet, responds instantly and, most importantly, is really, really fast.

The S54B32 won the overall International Engine of the Year award upon its introduction in 2001, then went on to win the 3.4-liter category for six straight years. It happens to be this particular Jalop’s favorite engine of all time, preferably housed in a flat black Z4 M Coupe, or in his dreams, a Caterham Super7, which would allow him to experience the engine as it repeatedly bounces off its redline in all its undiluted glory.

Worst of all, the fabled M3's 3.2-litre straight six will die too. This is a fantastic unit, a naturally aspirated engine with a metallic bark that’d do a supercar justice. It debuted in the ’90s E36 M3 as a 3.0-litre, swelling to 3.2 litres in the E36 M3 Evo, plus the 'ZM3' models and E46 M3. The Z4 M marks this iconic straight six’s swansong, a heady 343bhp nestling under your right foot. And, no, the new car doesn’t get the E92 M3’s V8. There will be three straight sixes on offer, stretching from a 2.5-litre 201bhp to a 302bhp twin-turbo 3.0-litre. All good, but none can match the 3.2’s sense of occasion."


In my opinion, the BMW Motorsport has lost its way. BMW has been a shameless leader in the grotesque obesity trend that has affected the evolution of automobile design since the late 1980's. I should note that the Japanese (the last hold outs) plunged headfirst into this trend in mid 2000's. I throw up in my mouth a little every time I see a late model Toyota Tacoma. This is to be expected, but Motorsport was supposedly different. Light, agile, normally aspirated performance cars designed for the track were its original mission. It seems that mission has shifted these days, with the M standing more for Marketing than Motorsport. Currently the smallest Motorsport vehcile weighs close to 4000lbs and the smallest Motorsport engine is a vibration happy V8. Okay it's probably pretty smooth, but no S54. With an M SUV and next year's turbo charged M5 debuting I don't see anything but a continuation of this trend.

I support the environmentally friendly rise of forced induction in modern cars, but am appalled at the size of most vehicles these are being used in. Most of efficiency gains are superficial at best, maintaining the current status quo as vehicles continue to grow larger. Until the have-your-environmental-cake-and-eat-it-too BMW 120d (50mpg, 0-60 in 7 seconds, top speed 135) comes to the US, the only current BMW I would park in my garage is a Mini Cooper! Lucky for me I've got a fine example of an S54 nestled in the lightest chasis possible. With Jo's gas sipping Honda Civic as a daily driver, I guess I can have a little cake and eat it too, but when that inline 4 wails under my foot I long for the smooth roar of the S54.

1 comment:

Airstream Basecamp said...

My brother drives an e36 M car with over 150k on the clock and it's still going strong. Just helped him replace the lower control arms and install a fresh set of pads\rotors, as it emerges from winter storage.

Pure Joy.