Mini makeover
Face-lifted 2007 edition to boast slick turbocharger in new engine

Sat Mar 26 2005

By Graeme Fletcher


ONE of the bigger complaints with the Mini Cooper is its engine -- the Chrysler-derived lump being overly gruff and, minus the Cooper S's supercharger, underpowered.

This will all change when a joint venture between BMW and PSA Peugeot Citron delivers a new family of 1.6-litre engines. Not only will these new aluminum engines be technically advanced when they debut in the face-lifted 2007 Mini, the Cooper S's existing supercharger will be replaced by a slick turbocharger.

The base naturally aspirated engine features a modified version of BMW's Valvetronic system. This clever bit of work dispenses with the traditional throttle plate by controlling the engine's speed and power output with the intake valves. Rather than being a purely mechanical system, the new design uses a small electric motor and a lever to control the amount the intake valves open -- an opening range that runs from 0.2 millimetres at idle to 9.5 mm at wide-open throttle.

At the same time, the variable valve timing (variable over 70 degrees on the intake side and 60 on the exhaust) spreads the power out while reducing fuel consumption and emissions.

Add to this an electric water pump (this reduces the time needed for the engine to reach operating temperature, which cuts fuel consumption and emissions during this critical period), a new oil pump (which cuts the usual power consumption by 1.7 h.p.) and an overall reduction in internal friction, and the new engine is said to reduce overall fuel consumption by nine per cent when compared with the current engine.

It also means better power over a much broader range. While the base engine retains the same 115 h.p. as the current engine, it develops its torque in a much more driver-friendly manner. Where the current engine needs to put 4,500 r.p.m. on the tach in order to produce its 110 ft-lbs of torque, the new engine develops 103 ft-lbs at 2,000 r.p.m. and a peak of 118 ft-lbs at 4,250 r.p.m. The up-level engine features direct fuel injection and a twin-scroll turbocharger. The former is a better (read more precise) way of introducing the fuel into the combustion chamber; the latter reduces the dreaded turbo lag for which so many blown engines are infamous.

In simple terms, the exhaust gas from the front two cylinders is fed to the turbo through one passage; the gas from the rear two cylinders through another. This bit of engineering means the turbo is ready to blow with all its might (11.75 psi) at just 1,400 r.p.m., which is exactly where the engine makes its peak torque of 177 ft-lbs. When compared with the current supercharged engine, this is 15 ft-lbs more torque at a significant 2,600 fewer r.p.m.

As for the horsepower, there will be at least two different versions of this engine. The first will develop 148 h.p., the second a much healthier 170, all of which has the rumour mill working overtime. If the general consensus is correct, both the Mini Cooper and Cooper S will use a version of the turbocharged engine, leaving the base naturally aspirated engine for the European-only Mini One and, perhaps, an entry-level version of the Cooper. Should this be the case, the Cooper gets a much needed hike of 28 h.p., which should drop its zero-to-100-kilometres-an-hour acceleration time from around 10 seconds to a more competitive time in the high eights. This, in turn, would leave the Cooper S the 170 h.p. engine.

Sadly, no official torque numbers have been released. However, if it keeps up with the other engines, somewhere in the 185-200 ft-lbs range (again at lower r.p.m.) would not be out of line.

Indeed, the true potential of the new turbocharged engines might only be limited by the need for reliability and longevity, which leaves one wondering what the replacement John Cooper Works edition will deliver. At present, it pushes a rewarding 210 supercharged horsepower. If the turbocharged Works engine follows the supercharged original's lead -- a ported and polished cylinder head, a hike in the boost pressure of a couple of psi and a reworked exhaust system -- 230 h.p. is well within the realms of possibility.

Other changes to the 2007 Mini are less speculative. The current clamshell hood (one hinged at the front of the car) will be swapped in favour of a conventional rear-hinged hood -- ironically, similar to the one penned by Sir Alec Issigonis, the father of the original Mini. The hood line will also be taller to accommodate the pedestrian protection regulations due in the next couple of years. These regulations call for some space between the engine and hood to allow the room for it to deform, which lessens the potential injuries to a pedestrian when struck by the car. The other changes are to the front grille and under-bumper treatment, the latter being necessitated by the new location for the turbo's intercooler. There's also strong speculation that there will be a four-door derivative of the current three-door hatch and, perhaps, a wagon (maybe dubbed the Estate).

--CanWest News Services

 

I posted the above and wondered what he meant by a "clamshell hood" hinged at the front. My MCS hood is hinged a the back already, no?

 

Mine's hinged on the side - makes it easy to fill one washer reservoir, but the other one's a bear!

 

Me too. Huh?

 

The author may have been sitting in his MG (with its front-hinged bonnet) while writing about future MINIs?? I suspect he meant to point out a particular (speculative?) change to the MINI bonnet, where it will no longer incorporate the headlamps?

It may be a matter of semantics but, to me, the bonnet is "clamshell" because of how it curves down forming the nose of the car.

Flame on, I'm an I/T guy not a gearhead
Tatt

 

I have a gullwing bonnet on my MCS

 

Must be available on UK only, but "once upon a time in the USA..." we had neato stuff like that too.

 

the o7 concept has a forward tilting clamshell hood.

its basicly just like a fiberglass tilt front end, fenders and all come up with it.

 

I have a toggle switch in my car that makes my bonnet become temporarily transparent and lets you put your hand right through it without feeling anything!

 

 

Yup, just like that! Dang, I thought I was the only one with this technology. It'll be standard on the '09s, I hear.

 

You just have to know how to harness the technology.

 

LOL those are neat! What i'd like to know is, does it sound like a light-saber when you stick your hand through, or more like the transporter on the Enterprise??

Good stuff,
Tatt

 

"ONE of the bigger complaints with the Mini Cooper is its engine -- the Chrysler-derived lump being overly gruff and, minus the Cooper S's supercharger, underpowered."



I don't like hearing people call the W11 a lump of crap... it's a damn fine motor that is tried and true'd here and in Europe. Who even knows what will happen with some new Peugeot motor, although a turbo might be cool, but still...



Ryan

 

(rolling up sleeves) ... okay repeat after me: BMW engineered the new engine, PSA is helping with logistics.

BMW will be building the next generation MINI's engine in the UK while PSA and will be producing their version in France.

(off soap-box)

 

I still don't like the W11 bashing...

 

Well, I am going to step into this, and I think I can say I have some experience with 4 bangers, having owned a Midget 1500, a Saab 9000, Mistubish Galant VR4, Honda Accord, Honda Civic and now a MINI Cooper.

I think the MINI power plant is a very nice 4 banger. Not saying that it can’t be improved upon, but it’s a fairly polished and seems to move the car well. Granted its only putting out 64Hp per l not any great accomplishment for a normally aspirated engine. Hondas getting what 100 hp per l out of some of there normally aspirated engines.