Drivetrain So why isn't the R56S 1.6L engine a high RPM 'screamer'?
6th Gear
Joined: Aug 2005
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From: SoCaL (Agoura Hills)
As for engines, the Tritec engine has been replaced in the Cooper model with a 120 bhp 1.6-litre Prince engine with BMW's Valvetronic infinitely variable valve timing, developed on and with Peugeot's core engine. It is reported in early road tests that this takes the car from 0-62 mph in a claimed 9.1 seconds (0-60 mph: 8.5 seconds)[12] and has top speed of 125 mph (201 km/h). Fuel economy of 48.7 mpg–imp (5.8 L/100 km / 40.5 mpg–U.S.) on the combined cycle is nearly 8 mpg better. The more powerful 175 bhp (130 kW) Cooper S replaces the supercharger with a new twin scroll turbocharger in the interests of efficiency, and will feature gasoline direct injection. Subsequently, this engine does not feature Valvetronic. This engine also has an "overboost" function which temporarily raises the torque by 15 ft·lbf (20 N·m) under hard acceleration. As a result, 0-62 mph is covered in a claimed 7.1 seconds (0-60 mph: 6.7 seconds),[12] and top speed is 140 mph (230 km/h). It achieves similar improvements in fuel economy to the Cooper, returning 40.9 mpg–imp (6.91 L/100 km / 34.1 mpg–U.S.) combined. Both cars come with six-speed manual or automatic gearboxes. The turbocharged engine is the same (although with some French engineering modifications) as the one in the Peugeot 207 GTi/RC.
2nd Gear
Joined: Jun 2007
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The lack of Valvetronic in M engines has to do with greater efficiencies using individual throttle bodies... It's also mostly a gas milage technology, not a performance one (That's where VANOS comes in). Most of the gas milage gains are lost when stiffer valve springs are installed for the higher RPM redline.
Here's a decent explanation:
"The efficiency of Valvetronic engines drop rapidly at over 6,000 rpm since stronger valve springs are required. The stronger springs create higher friction losses. Don't expect to see Valvetronic in the "M" series engines any time soon."
Here's a decent explanation:
"The efficiency of Valvetronic engines drop rapidly at over 6,000 rpm since stronger valve springs are required. The stronger springs create higher friction losses. Don't expect to see Valvetronic in the "M" series engines any time soon."
we're coming to the same point, just from different vantage points.
given that the Prince motor (and the tritec for that matter) is a forced induction motor, that sort of obviates the need for high rpms to make power (i.e. the way naturally aspirated engines have to make power) as well as the fancy valvetrain that N/A engines need.
Neutral
Joined: Mar 2007
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Hey guys interesting conversation. Just an opinion from someone with similar engine characteristics, but the 08 GTI I bought has a very similar engine profile to the MCS with super high torque at the expense of high RPM breathing.
In the 30th anniversary GTI in Europe, a slightly larger turbo produces 60 more HP pulling all the way to redline. I would think that a small 1.6L 4 cyl with a larger turbo (GT25, GT28RS ??) could put up incredible HP numbers in the MINI considering what you guys are seeing on the stock turbo. If you gave up some low RPM torque, down to say 220 lb ft at 2500 rpm, you coul easily slap a turbo on that could rev very high.
In the 30th anniversary GTI in Europe, a slightly larger turbo produces 60 more HP pulling all the way to redline. I would think that a small 1.6L 4 cyl with a larger turbo (GT25, GT28RS ??) could put up incredible HP numbers in the MINI considering what you guys are seeing on the stock turbo. If you gave up some low RPM torque, down to say 220 lb ft at 2500 rpm, you coul easily slap a turbo on that could rev very high.
2nd Gear
Joined: Nov 2007
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From: North Carolina
You are correct! The valvetronic in the Cooper varies the valve lift from about 0.2mm to about 9.8mm, if my memory serves me correctly, and this variable valve lift eliminates the need for a throttle body. However, I believe that the throttle body is still there, in case the valvetronic fails. The MCS does not have valvetronic, but has VANOS, which is variable valve timing, but only on the intake valves.
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4th Gear
Joined: Mar 2008
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From: 40°-55'-44" N / 73°-24'-07" W [on LI]
Hey guys interesting conversation. Just an opinion from someone with similar engine characteristics, but the 08 GTI I bought has a very similar engine profile to the MCS with super high torque at the expense of high RPM breathing.
In the 30th anniversary GTI in Europe, a slightly larger turbo produces 60 more HP pulling all the way to redline. I would think that a small 1.6L 4 cyl with a larger turbo (GT25, GT28RS ??) could put up incredible HP numbers in the MINI considering what you guys are seeing on the stock turbo. If you gave up some low RPM torque, down to say 220 lb ft at 2500 rpm, you coul easily slap a turbo on that could rev very high.
In the 30th anniversary GTI in Europe, a slightly larger turbo produces 60 more HP pulling all the way to redline. I would think that a small 1.6L 4 cyl with a larger turbo (GT25, GT28RS ??) could put up incredible HP numbers in the MINI considering what you guys are seeing on the stock turbo. If you gave up some low RPM torque, down to say 220 lb ft at 2500 rpm, you coul easily slap a turbo on that could rev very high.
...but I/we digress ...
Neutral
Joined: Jul 2007
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From: Austin
Me too... I know you were talking about a different car, but that is why I wish the mini had more RPM's to play with.
6th Gear
Joined: Aug 2005
Posts: 3,902
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From: SoCaL (Agoura Hills)
Aside from the lifters getting a bit sketchy past about 8300 RPM's, with an upgraded valvetrain you can rev to 8 grand pretty much all day.
2nd Gear
Joined: Jun 2007
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seems like the posi-displacement blower wouldn't be all that compatible with a wide rev range; usually in OEM apps, they're for low end power more so than top end, no?
3rd Gear
Joined: Sep 2007
Posts: 192
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its a problem with all forced induction cars. you have to spec the turbo/supercharger to what you want. this will have an impact on how the engine behaves. small turbo give you great lw end responce but tend to choke the engine at higher rpm (that exhaust housings cant flow enough and the cold side gose well out of the efficency band loosing boost and super heating the air). on the other hand big turbos take more power (and thus RPM) to spool. this usually means you loose out down low but gain higher up the RPM band.
what you need to do is looks at what you want the car for, your power and torque goals and then decied on the turbo/engione combo to go for.
with the stock MCS, the engineers are trying to make a car with a little engine that feels like a BIG engine. this means small turbo and lower RPM. if you compare it to something like and EVO, where boost responce is less of a concern, you see they dont make full boost till much later in the RPM band.
its all about specing the turbo and engine combo to what you are looking for. sprint/autoX stick to small fast responding turbos, drag/fast street use a slightly larger trubo.
Chris.
what you need to do is looks at what you want the car for, your power and torque goals and then decied on the turbo/engione combo to go for.
with the stock MCS, the engineers are trying to make a car with a little engine that feels like a BIG engine. this means small turbo and lower RPM. if you compare it to something like and EVO, where boost responce is less of a concern, you see they dont make full boost till much later in the RPM band.
its all about specing the turbo and engine combo to what you are looking for. sprint/autoX stick to small fast responding turbos, drag/fast street use a slightly larger trubo.
Chris.
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