Theoretical top speed of Z4M?

ManoSpeed · 04-20-2011, 11:21 AM

The other day I was wondering if anyone knew what the top speed of the Z4M is if the limiter were to be removed. What is this car capable of doing in terms of top speed?

Anyone knows?

BTM · 04-20-2011, 11:30 AM

Using stock ratios, 25" tire dia, and 8200 fuel cut off, gear limited top speed is about 193mph

r4gs · 04-20-2011, 11:48 AM

^so essentially, a completely stock z4m is capable of 193mph? what's the verifiable source?

arggg45 · 04-20-2011, 11:51 AM

Quote:

Originally Posted by r4gs

^so essentially, a completely stock z4m is capable of 193mph? what's the verifiable source?

That's assuming no wind resistance.

There's another thread on here somewhere about this.

lucid · 04-20-2011, 11:58 AM

Quote:

Originally Posted by r4gs

^so essentially, a completely stock z4m is capable of 193mph? what's the verifiable source?

He stated the gear limited top speed. (which might be slightly different than stated because the actual rolling diameters of tires differ slightly from specs).

Regardless, the car should be drag limited prior to reaching that speed (meaning, it will stop accelerating at a lower speed due to not being able to overcome drag). It is possible to calculate the power to overcome drag at different speeds based on the specs of the car, but that won't account for friction elsewhere such as the drivetrain and tires.

Anyway, I would rely on the manufacturer's claim (if they ever released it), or on a report of what the car might have done on the autobahn with GPS validation--not that I think it is a good idea to test that in any sort of public road even when it is legal to do so.

The HACK · 04-20-2011, 11:58 AM

Terminal velocity when dropped out of an airplane for the MZ4 is about 180mph I think.

lucid · 04-20-2011, 12:01 PM

Quote:

Originally Posted by The HACK

Terminal velocity when dropped out of an airplane for the MZ4 is about 180mph I think.

Why is that relevant?

FerRrari · 04-20-2011, 12:04 PM

No, a stock Z4M won't do anywhere near 190 MPH, somewhere around 170 MPH is more realistic

Eccentric · 04-20-2011, 12:23 PM

I've seen 173mph on video.. nothing higher than that has graced my comp screen

txz4 · 04-20-2011, 12:48 PM

Quote:

Originally Posted by Eccentric

I've seen 173mph on video.. nothing higher than that has graced my comp screen

seen many magazines stating that the car would go 190 de-limited, though that seems a little optimistic to me...

cmark8 · 04-20-2011, 12:53 PM

190mph speedometer measured is somewhat believable. But real speed? That's highly doubtful.

Z4Murder · 04-20-2011, 01:51 PM

low 170s drag limited sounds about right

Hawkeye · 04-20-2011, 01:59 PM

Quote:

Originally Posted by The HACK

Terminal velocity when dropped out of an airplane for the MZ4 is about 180mph I think.

Prove it.

esqu1re · 04-20-2011, 02:00 PM

For comparison, the last NSX had a top speed of 175 from a 290hp (underrated) engine. The Cayman S has a top speed of 171.

I would probably guess our cars can hit vmax of ~170.

MFGJR · 04-20-2011, 05:50 PM

Quote:

Originally Posted by The HACK

Terminal velocity when dropped out of an airplane for the MZ4 is about 180mph I think.

Dammit! I missed ANOTHER episode of Top Gear...

Starscream · 04-20-2011, 06:17 PM

When they were first released I remember reading something either from BMW or from spartanburg claiming the top speed to be in the 170's de-limited,

I'm sure it was to the higher end of the 170's too,

psygnosis · 04-20-2011, 06:18 PM

I tested it in Forza 3 a while back and without messing with any settings it was about 170-180

edit: http://www.zpost.com/forums/showthre...ighlight=forza

Quote:

Originally Posted by psygnosis

So I tested this out in Forza 3 on the Xbox. Highest speed I could get on a stock setup with the M Coupe was 173mph in 5th, this wasn't quite at redline and I couldn't get anything more from 6th gear, edit: Taking into account the ~3% speedo error, an actual car probably would have shown about 178mph. With level 1 intake and exhaust with maximum weight reduction I got to about 180.

BTM · 04-20-2011, 06:39 PM

Quote:

Originally Posted by lucid

He stated the gear limited top speed. (which might be slightly different than stated because the actual rolling diameters of tires differ slightly from specs).

Regardless, the car should be drag limited prior to reaching that speed (meaning, it will stop accelerating at a lower speed due to not being able to overcome drag). It is possible to calculate the power to overcome drag at different speeds based on the specs of the car, but that won't account for friction elsewhere such as the drivetrain and tires.

Exactly. That is about top speed assuming that the car's power can overcome all the friction (atmosphere, contact patch, etc).

Additionally, comparing cars deregulated top speed with similar power won't tell much without comparing their cD to the Z4's. Coupe or roadster will also make a difference, since it's aerodynamic footprint is not identical. You would even expect things such as ambient temperature, elevation (air density), tire pressure, and road surface to have slight effects.

The maximum speed the gearing will allow is about 193. All of the above factors are going to work against achieving that MPH. How much of an effect each variable will have is also dynamic, meaning that they might never be exactly the same, lending to the reason that official top speed runs are an average of 2 back to back runs in opposite directions.

Even then, I tend to think of top speed in a similar way I do lap times, or baseball statistics. They are only 100% accurate in reporting what has happened, and can give a general idea of what a car (or player) is capable of, but is no where near a perfect predictor, as there are too many uncertain, unmeasurable, and unreproducible externalities not only built into the numbers already recorded, but any subsequent numbers as well.

rabbit69 · 04-20-2011, 06:45 PM

275 kph, with rev limiter

The HACK · 04-20-2011, 07:27 PM

Quote:

Originally Posted by lucid

Why is that relevant?

That's the theoretical top speed.

lucid · 04-20-2011, 08:00 PM

Quote:

Originally Posted by The HACK

That's the theoretical top speed.

That is (perhaps) what it would do if it were to be acted on by gravity alone in mid air. What you are referencing is the terminal velocity of a free falling object, which doesn't have much to do with a car travelling on a road under its own power. If it had 1000whp, it would do 200mph+ (assuming it is stable at that speed and tires hold up, etc); it wouldn't all of a sudden stop accelerating at 180mph. If the force at the tires exerted by the drivetrain is larger than the opposing drag force, the car is accelerating. Nothing more to it than that. At 200mph the stock tires might not hold up, but I suspect the car would be "stable" but "shaky" if it had enough power to overcome air resistance. If power is not an issue, the true "theoretical" top speed on the road would be dictated by when it becomes unstable--mainly generate too much lift--and become uncontrollable.

pal · 04-20-2011, 08:03 PM

I did 155.4 mph in the standing mile at Texas last March - measured by their equipment; 156 mph on a Garmin GPS inside the car as I let off a bit after the mile

I was in 5th gear and the car was still pulling but not as hard as it was in the first 1/2-3/4ths mile. Even got a little famous

04-20-2011, 11:21 AM	#1
ManoSpeed Private First Class 24 Rep 160 Posts Drives: 2007 BMW Z4 M Coupe Join Date: Sep 2010 Location: Elk Grove Village, IL iTrader: (0) Garage List 2007 BMW Z4 M Coupe [8.00]	Theoretical top speed of Z4M? The other day I was wondering if anyone knew what the top speed of the Z4M is if the limiter were to be removed. What is this car capable of doing in terms of top speed? Anyone knows?
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04-20-2011, 11:30 AM	#2
BTM Banned 483 Rep 10,309 Posts Drives: A///MERICAN!!! Join Date: Mar 2010 Location: A///MERICA!!! iTrader: (11) Garage List 2007 BMW Z4 M Coupe [7.20]	Using stock ratios, 25" tire dia, and 8200 fuel cut off, gear limited top speed is about 193mph
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04-20-2011, 11:48 AM	#3
r4gs Viper Driver 36 Rep 1,311 Posts Drives: F-16 Join Date: Aug 2010 Location: Singapore iTrader: (2)	^so essentially, a completely stock z4m is capable of 193mph? what's the verifiable source?
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04-20-2011, 11:58 AM	#6
The HACK Midlife Crises Racing Silent but Deadly Class 1820 Rep 5,337 Posts Drives: 2006 MZ4C, 2021 Tesla Model 3 Join Date: Oct 2007 Location: Welcome to Jamaica have a nice day iTrader: (1)	Terminal velocity when dropped out of an airplane for the MZ4 is about 180mph I think. __________________ Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
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04-20-2011, 12:04 PM	#8
FerRrari First Lieutenant 19 Rep 389 Posts Drives: Catrinel Menghia Join Date: Sep 2010 Location: WA iTrader: (1)	No, a stock Z4M won't do anywhere near 190 MPH, somewhere around 170 MPH is more realistic __________________ '12 Nero/Rosso 500 Abarth '07 IR/SBL ///M Roadster (GONE), '08 Tornado Red Triumph Daytona (GONE), '09 BRG/Cloth 6MT MINI Cooper S (Spontaneously Combusted), '06 IR/IR ///M3 Convertible 6MT (GONE), '04 JB/CR Z4 2.5i SMG (GONE)
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04-20-2011, 12:23 PM	#9
Eccentric Lieutenant 51 Rep 576 Posts Drives: Interlagos Z4 M Coupe Join Date: Jun 2010 Location: In a van, down by the river. iTrader: (0)	I've seen 173mph on video.. nothing higher than that has graced my comp screen
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04-20-2011, 12:53 PM	#11
cmark8 M52, M62TU, S50US, S54, S65 75 Rep 569 Posts Drives: E90 M3 6MT, E36 Touring MT Join Date: Jun 2010 Location: +5511 iTrader: (11)	190mph speedometer measured is somewhat believable. But real speed? That's highly doubtful. __________________ 1995 E36 M3 USA / 2002 E46 M3 SMG / 2008 E90 M3 6MT 1996 E36 328i Touring 5MT / 1998 E36 323Ti M Sport 5MT 2002 E39 540i Protection
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04-20-2011, 01:51 PM	#12
Z4Murder Major 28 Rep 1,110 Posts Drives: > speed limit Join Date: Apr 2010 Location: Buffalo, NY iTrader: (1)	low 170s drag limited sounds about right __________________ 2007 TiAg ///MCoupe * Dinan strut bars * ZHP knob * RPI scoop * Ultimate Pedals * RE Diablo * 3.91 TMS gears * Apex PS7 * Eventuri intake* Nitto NT05 * TMS pullies * Zeck CDV * RE tranny mounts * Tekarbon * Mstache 2 * '14 Jeep Grand Cherokee Overland Hemi... No more snow for the M!
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04-20-2011, 02:00 PM	#14
esqu1re Lieutenant Colonel 41 Rep 1,855 Posts Drives: M Coupe Join Date: Jul 2010 Location: East Coast iTrader: (0)	For comparison, the last NSX had a top speed of 175 from a 290hp (underrated) engine. The Cayman S has a top speed of 171. I would probably guess our cars can hit vmax of ~170. __________________ ///M Coupe: RPI Scoop, OE Strut, CDV, Volk RE30, SS Brake Lines, Stromung Exhaust
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04-20-2011, 06:17 PM	#16
Starscream Colonel 135 Rep 2,120 Posts Drives: ///M Roadster + E92 335i 6MT Join Date: Dec 2007 Location: Park Ridge NJ + Windermere FL iTrader: (23)	When they were first released I remember reading something either from BMW or from spartanburg claiming the top speed to be in the 170's de-limited, I'm sure it was to the higher end of the 170's too, __________________ Imola Red Roadster
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04-20-2011, 06:45 PM	#19
rabbit69 Private First Class 6 Rep 131 Posts Drives: z4m roadster Join Date: Dec 2010 Location: Ottawa iTrader: (0)	275 kph, with rev limiter __________________ 06 Z4MR Imola red 11.8@122
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04-20-2011, 08:03 PM	#22
pal Captain 433 Rep 753 Posts Drives: Z4 M Coupe Join Date: Nov 2007 Location: Seattle, WA iTrader: (2)	I did 155.4 mph in the standing mile at Texas last March - measured by their equipment; 156 mph on a Garmin GPS inside the car as I let off a bit after the mile I was in 5th gear and the car was still pulling but not as hard as it was in the first 1/2-3/4ths mile. Even got a little famous
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