Not since the 1.8T and its subsequent replacement has a motor been as highly anticipated as BMW's new 3.0 twin-turbo. First seen in the 335i Coupe, why is this such an important car?
Firstly, it's a new 3-Series Coupe. These are landmark cars that set the benchmark for handling, performance, comfort, luxury and style in their competitive market sector.
Like all the BMW range, the E90 3-Series sedan has slightly controversial styling, but familiarity is softening the edges. And the new E92 3-Series Coupe is probably the least offensive of them all (E91 is the wagon, E93 is the convertible) with its flowing lines and muscularity. In fact, we're told the only common parts between the E90 and E92 are the door handles, so the Coupe is effectively a brand new car.
Companies like Lexus have been chasing the 3-Series for many years. And the arrival of the new IS350 changed the status quo. For the first time in its existence, the 3-Series isn't the most powerful car in its class.
Armed with a new 3.0 bi-turbo, it would've been easy for the E92 to outgun the IS350, but BMW executives confessed distaste for escalating the power struggle. They're so confident the Coupe is superior in every other detail, they've allowed Lexus to win the numbers game - although naming the new car 335i when it's technically a 3.0T shows they're not taking the threat lightly.
Another reason why the 335i is so important is the motor. Three hundred horsepower from its high-revving, torque-laden, magnesium alloy straight-six is enough for most occasions, and it's got the BMW tuners salivating.
For years the VAG market had things easy. A chip, intake and exhaust on any 1.8T would give the car a swift kick up the tailpipes. The BMW tuners looked on enviously, but not for much longer.
We've spoken to several BMW specialists that have cars on order and are speaking to European tuners to crack the computer code.
This car is built for tuning. BMW's engineers fitted two relatively small turbos to successfully erase lag. In doing so, they're inviting tuners to electronically turn up the boost and have some fun. There's plenty of room for a bigger front-mount intercooler, and surely bigger turbos are just around the corner...
The Man From MunichWe had a chance to speak to the Coupe's Powertrain Project Manager, Udo Lindner, with a view to understanding the car's tuning potential. The first thing we asked was about the engine's development. "Before we came up with the world's first straight-six direct-injection twin-turbo engine, we looked at supercharging during development but rejected it on grounds of efficiency. We have also taken the engine to a higher power level but felt 300hp was a good limit because it really doesn't feel like it's turbocharged. It feels like a large, naturally-aspirated engine where response is very good. If you produce more power you start to feel the turbos and then you notice some lag," he told us.
"We have a problem keeping up with our competitors at the moment, but this is a very good engine," he continued. "If you adjust the electronics you can obviously increase the boost and get more power, but then you start to have a different feel. For BMW the feel was very important because this is our first turbo engine in 25 years, so it had to be right.
"It's easy to get more boost but for a tuner it's not always simple to do it under all conditions - at cold start, when hot and at altitude, for example. And there's a problem with the exhaust downpipe. With more power it gets very hot and will break."
"When we were looking at the E90 we investigated all options, including V8, V6, etc. However, our engineers showed us that with direct injection there were real advantages from a turbocharged engine. We feel direct injection gives the gasoline engine a better future than people predicted against diesel and hybrids. And the second generation of direct injection is an important breakthrough in power delivery and emissions. For example, under load at low revs we have three injections per cycle to get the correct engine response," Udo continued. "As a result, we hope to bring direct injection to more engines. A direct injection 3.0 has about a 10% improvement over a Valvetronic 3.0, for example.
"We also looked at variable vane turbos and other technology during development, but with our Vanos system these were unnecessary."
At this point, we discussed fuel octane and its relevance to direct injection in the 335i. "This engine won't run on 91 octane," we were told. "But that's all we've got in some States," we retorted. Silence followed. Then there was a discussion about how octane was calculated differently in the USA and Europe: We were assured it would be ok. "There may be some power loss, and this will be most noticeable when the engine's cold at low revs. However, we've developed a version of this engine to run in China on 87 octane, so it'll be ok. On the other hand, if you run the car on 100 octane you won't see more than 300hp. We have 100 in Germany and there are no gains in either power or economy because the electronics are optimized."
So what's under the 335i's hood? "We have two Mitsubishi turbos running at 0.6bar (8.8psi). These can boost to 0.8bar to compensate for altitude using the two electronically-controlled wastegates," Udo explained.
"The airbox has two outlets. One goes in front of the engine to the front turbo, the other goes behind. And the liquid-cooled turbos face in different directions for this reason," he continued.
We pressed Udo about whether the BMW engineering team had been inspired by any tuners. After all, there have been twin-turbo conversions in Germany for several years. "It's always good to see what tuners can achieve with relatively small R&D budgets," he confirmed, "but I'm frustrated by their one-dimensional approach. For them it's about power, torque and acceleration, whereas a manufacturer must be multi-dimensional and create an entire package. That's why we're so proud of the new engine because you can't feel the turbos. However, I acknowledge there's a group of people who always want more, and turbocharging makes that possible."
So did BMW consider the tuners when finally selecting the bi-turbo configuration? "We looked at a V8 and other options, some of them crazy, and certainly the twin-turbos had many advantages. It's tuning potential was a small consideration, but it was considered."
So why is it so difficult for tuners to crack BMW engine management systems? "This is a combination of their complexity and our security. We can't make it too easy or we would invite all sorts of warranty claims and our engines would get a bad reputation," Udo suggested.
And why is the 335i "only" 300hp?"This is the first time BMW doesn't have the most powerful engine," Udo confirmed. "The IS350 with 305hp has that honor, but we could easily build our engine to produce 310hp. However, we didn't want to start a power struggle; that would be silly. And although we have fractionally less power, we have really good torque. It produces 300 lb/ft from 1400 to 5000rpm. This is important for everyday use. But the engine is flexible and we could easily give it more power if it became necessary.
"We have many other developments we're working on," Udo continued. "We have a lot of diesel technology that doesn't come here, but our next big development will be lean burn. We're working on four and six cylinder engines we expect to be very efficient. The second generation lean burn technology has many advantages, but again it can't come to the USA because of your NOX emissions laws. So we must build Valvetronic engines, diesels and lean burn. And then there are things like ethanol and hydrogen around the corner, so it's very expensive for a small company like BMW."
After our discussion we got the feeling Lindner was almost offended anybody would tune his engine. Having taken so long to make it "perfect" he can't understand why we'd want to modify it. And yet he was resigned to the fact he'd just provided the aftermarket with the perfect tools.
Other HighlightsWhere do we begin? The E92 will also be available in 328i guise. This is a detuned version of the 3.0 motor in the current 325i, which it will replace. According to Lindner, the difference between the 328i and 325i "are subtle and mainly electronic."
Furthermore, there will be a 328xi Coupe with four-wheel drive for the first time. This features the XDrive system that has 100% variable power distribution.
Performance from the three derivatives is impressive. The 300hp 335i hits 60mph from standstill on 5.3sec using the six-speed manual transmission from the 550i (the six-speed auto is slightly slower at 5.5sec). The 230hp 328i manual gets there in 6.2sec, with the 328xi following at 6.8sec.
The Coupe gets an almost completely new body and several new paint colors, as well as exclusive interior finishes, helping to justify the car's price premium over its sedan sibling. Yet it also gets a higher standard specification, including adaptive Xenon lights with angel eyes and two-stage adaptive LED brake lights on the rear, 17" wheels with sports suspension, sports steering wheel, etc, etc.
The Coupe also gets an electric water pump, magnesium steering mechanism, aluminum engine components and plastic fenders. These combine to make it 22 lb lighter than the sedan, yet it's 25% stiffer.
The car is laden with all the electronic features you've come to expect from a world leader in automotive engineering, and unfortunately, we don't have space to list them all here.
From The Back SeatHaving come to terms with BMW's new look, it's funny how right the Coupe looks. It sits properly and has some really nice lines. A BMW Coupe is a driver's car, and this is a remarkable one.
After two minutes behind the wheel we understood why Udo Lindner didn't want people messing with his engine. There's absolutely no turbo lag. The engine just pulls from idle with seamless power. It's incredible.
We took it on a 1500 mile journey from San Francisco to Bonneville to LA and discovered this is an incredible GT. It's the perfect companion - quiet, incredibly comfortable, has enough toys to keep you amused, yet there's sufficient power to entertain when required.
The motor has limitless torque. In fact, we'd drive it like a V8 - slot it into sixth and let it pull from 1200rpm, without fuss or complaint. Yet it's utterly smooth up to the redline.
On our epic journey we encountered everything, from twisty mountain passes to wide-open desert. In the mountains the car has so much poise it didn't even wake the crew when things got exciting. The brakes are incredible, the body roll acceptable and bump absorption is beyond reproach.
And the 335i is no showroom poseur. It'll mix it with the best in the twisties and then bounce off the speed limiter in the straights.
I have to admit, somewhere in the desert, after hour upon tedious hour of 75mph conformity, I floored it. The engine, road and wind noise increased but the car was totally stable. We went to redline in fourth, dropped in sixth and it pinged off the 155mph limiter at about 5500rpm, with plenty more to come.
The 335i Coupe is a great car to ride in and a perfect car to drive. We all want one. It really doesn't get much better than this.
This car is so good I caught myself thinking I'd leave it standard, to enjoy it without compromise. Then I started thinking about the twin-turbos, the cavernous fenders, and I'd built a project car in my head. - Greg
Most of my time in the 335i was either in the passenger or back seat (no, not like that!). Greg was the wheelman for the majority of the Coupe's miles to and from Bonneville, so I accustomed myself with the interior. It was comfy and roomy, much like a sedan. The two back seats have ample space to move around. However, the passenger's sport seat is more appealing - what would you expect from a BMW?
Being the geek I am, I particularly appreciated the LED lights along the interior door panels. It added a luxurious element in the dark. I also have to commend BMW for the new 13-speaker Logic7 audio system. The bass pounds strong and the volume can be increased to ear-bleeding levels without distortion. Also standard is an auxiliary input jack, which came in handy for my iPod.
My only gripes with the interior were the walnut trim and the automatic seatbelt presenter. Because BMW designed the seatbelts to anchor behind the long doors, the engineers constructed mechanical arms to bring the belts to the front seat occupants. It's a fancy tool, but I found myself knocking the belt off the arm several times. I can only imagine the number of times owners will dismember this piece because of its flimsy plastic.
Once I had the opportunity to drive the 335i, it was an unforgettable experience. This car lives up to BMW's ultimate driving machine motto. The 300hp feels accessible across the entire powerband and in every gear.
Surprisingly, there's absolutely no lag from the twin-turbos. It effortlessly reached 60mph from a dead stop, and accelerates easily to 120mph from there.
The suspension is what you'd expect from a BMW. When cruising, the ride comfort is exceptional. Even when accelerating over 100mph, it handled like it was meant for high speeds. Cornering was magnificent; whether on a freeway ramp or tight, windy roads, we experienced minimal body roll.
If $40k weren't an issue, I wouldn't hesitate to make this my next project car. The prospect of tuning the twin-turbo system with software, intake and exhaust, lowered suspension, slightly more aggressive body styling, bigger brakes and a set of 20" forged wheels, means this BMW would be my dream car. - Sam
As I slid behind the wheel of the highly anticipated 335i Coupe, I hadn't a clue about its pedigree. Cloaked in secrecy, the elegant, business-like Coupe was said to be the best 3-Series ever, with E46 M3 performance to boot.
Studying the spec sheet, the car looked promising with its sophisticated suspension, 50:50 weight distribution and 300hp. But despite the numbers, my first jaunt left me dissatisfied. The car was supple, understated and fast, but it definitely wasn't an M car. After several hundred miles, I realized I was expecting an iteration of the venerable M3; a taut, apex-cutting screamer - something the 335i is not.
Instead, BMW's newest coupe is a perfect blend of speed and civility: the proverbial velvet hammer, if you will. And hammer it does, as the boosted six doesn't disappoint.
More than the power, it's the mountainous 300 lb/ft delivered from 1300-5000rpm that defines the car. Ignore the tach and let it rip, the new mill pulls with the ferocity of the S54 in all but the upper gears.
Most importantly, I see the 335i with its factory boost and great suspension as the perfect platform for the aftermarket: only a few upgrades away from serious Porsche territory. - Justin