06-09-2013, 02:05 PM | #1 |
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Top speed
Testet the top speed of our 116i on the Autobahn this week.
BMW claims 210 km/h, but I suspected it could do more since it has been measured to 139 hp at the rear hubs. I was wrong. It could not do more than 209 (GPS). Tried fifth and sixth gear, Comfort and Sport+ modes. It didn't feel like it hit a limiter. The acceleration was very slow above 200 km/h, so I think it simply ran out of power. Small inclines made it decelerate. The speedometer indicated around 215. I have two ideas to explain why the top speed isn't higher. 1) The F20 has aerodynamics like a brick. 2) The dyno measured power is only temporarily boosted, and power drops down to a lower level after some time to avoid overheating. As a reference, my old E30 318iS did 219 km/h with less power, and it really looked like a brick. It did have a smaller front area, though. Did anyone else test their top speed? |
06-09-2013, 02:18 PM | #2 |
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I have hit the limiter multiple times with the m135i. Its 260 at the tacho. You can feel its electronically blocked to go faster. It also does this nearly in 6th gear. At 255 shifting to 7th. Goes pretty fast to 260 as well
About overheating : get a better intercooler. That can help. |
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06-09-2013, 02:25 PM | #3 | |
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I don't need a higher top speed, as I never need to drive 200+ km/h anyway. It is a very unefficient and dangerous way to drive. I just want to understand why the top speed is not higher than it is. |
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06-09-2013, 02:45 PM | #4 |
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The 116i has a software limiter at 130mph, even with the 200bhp ACS piggy back ecu it only does 130mph.
It was done to peg the top speed back and give a 10mph gap to the 118i which is also restricted to 140mph. (125i has an unlimted top speed of just over 150mph) Cheers Lee Last edited by logiclee; 06-09-2013 at 03:02 PM.. |
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06-09-2013, 02:51 PM | #5 |
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06-09-2013, 02:55 PM | #6 | |
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The 116i has the same engine as the 118i but it's power and top speed is capped. All about market position and price point. ACS posted earlier Both the 116i and the 118i are top speed limited via the CAN BUS. AC Schnitzer engine tuning does not remove the speed limit. Cheers Lee |
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06-09-2013, 02:57 PM | #7 | |
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And I did not fold in the mirrors! :-) The ambient temperature was 20C. Maybe it would have been better for the car with lower temperatures. More drag, but also more power. I don't know. My tires are 205, which should have less rolling resistance and drag than the wider stock tires. I had not overinflated them, which also helps for top speed runs. Wanted to make it all realistic. |
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06-09-2013, 03:00 PM | #8 | |
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Just guessing here, don't know for sure. |
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06-09-2013, 03:08 PM | #9 | |
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Someone else on another forum said it was very noticeable especially on slightly down hill sections. Cheers Lee |
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06-09-2013, 04:31 PM | #10 | |
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I would have noticed if the GPS was counting steadily up, and just always stop at the same number. At 190+ km/h, you can not actually feel the acceleration, just watch the speed climb slowly on the speedometer. I talked to a Hartge dealer who had been in an F20 114i test car. It topped out at 180 km/h. Then they hit the switch to enable the Hartge box, and it went on to do 210. According to him, that was a VERY noticeable power boost. |
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06-09-2013, 04:58 PM | #11 |
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I've read somewhere that the 116i does come with an overboost function, but that's supposed to raise the torque in the midrange, but does not actually increase max power.
I've hit the limiter on my car as well, on an actual road and on the dyno. From the way it feels, I'd say that the limiter does not work over the fuel injection, but rather on the electronic throttle. Specially while on the dyno, the car topped out at 240kph on 6th and would not rev further. I tried shifting to 7th and 8th gear and it kept steady at 240kph. On the road, it's much more subtle, and sort of feels like the car's run out of steam, instead of actually hitting a limiter. But specially downhill you can tell that the car could still go a little faster. |
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06-09-2013, 07:27 PM | #12 |
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My 1.5 cent... (not quite 2 cents )
(1) F20 does have the aero coefficient of 0.33 of a brick. Toyota Prius has something like 0.26 for Cd. But the test car in BMW has the same Cd and frontal cross area. For laughs the new 3 series has something like 0.28.... Since BMW test car has the same body as your car, aero effect should have canceled itself out. I digress, but when the new new 1 series comes out this aero drag should be one of their considerations.... A reference link: http://www.motoringpro.com/news/merc...on-model-world (2) I think the magazine companies test top speed with nothing but the driver on the car. They do one run one way, and the other run in the opposite direction and average out the speed, in hopes to cancel out the wind or any imperceptible on the road. Plus, who knows how much fuel they got on board. They have this device dedicated to measuring high speed, and that's what the TV shows go by. I tested out three GPS and there are 1 to 3 km/h differences, which may contribute to the differences you see. |
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06-10-2013, 01:15 AM | #13 |
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Searching the net, I found the Cw value to be 0.31, and the frontal area 2.14 m2. That should give a drag force of 1354 N at 210 km/h.
At 210 km/h with 139 hp at the rear hubs, there should be a forward force of around 1750 N from the driveline. The rolling resistance should be no more than 300 N, leaving 1450 N to combat aero drag. The difference is not so large, so it could be explained by slightly lower power due to temperature and not hitting the optimal RPM. So I guess that F20 has aero like a brick! Due to lower cross sectional area, my old E30 was actually slightly more aerodynamic than the F20. That explains it for me. Last edited by ovekvam; 06-10-2013 at 03:02 AM.. |
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06-10-2013, 01:39 AM | #14 |
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Yes I am parking my car right next to an E30 325i, looking at them I must say I am somewhat surprised that they come up with something less aerodynamic with seemingly rounded shapes.
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06-10-2013, 02:48 AM | #16 |
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I'm suprised that is could do 210 km/h, BMW states 200 km/h.
I'll pick up a 116d this Thursday, which will be very exciting! Coming from a 184 hp Cooper S I would guess it will be quite a difference. By the way, I think the Cooper S had the same engine as the 116i/118i which is called N13 when it sits in a MINI and N18 in a BMW. It's a very nice engine, but I hope they've got rid of the problems with carbon building up in the cylinder heads. http://en.wikipedia.org/wiki/Prince_engine |
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06-10-2013, 07:26 AM | #17 | |
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06-10-2013, 07:32 AM | #18 | |
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The 116i is electronically limited to ~212 km/h. By the way a clear indication is, that the current fuel consumption is stable around 14-15l/100km at 212 km/h even if you floor the pedal. Yes the car could go a little faster. But who cares, except for BMW who didn't want to get into 118i regions. It's fast enough for Norway and even fast enough for the German Autobahn considering most people drive around 130-160 km/h (mainly due to the fuel prices here). Last edited by Aspe; 06-10-2013 at 07:54 AM.. |
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06-10-2013, 07:52 AM | #19 |
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06-10-2013, 07:53 AM | #20 | |
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