Gear speed 6MT vs DCT!!!

[icemang17]

Using this calculator I determined the speed in gears at redline 8400rpm for both M3's

http://www.autolounge.net/calculators/gearing.html

Heres the 6MT
1st 43 mph
2nd 73 mph
3rd 111 mph
4th 148 mph
5th 171 mph
6th 196.2mph

The DCT is:
1st 43mph
2nd 71mph
3rd 97 mph
4th 124 mph
5th 150 mph
6th 173 mph
7th 208.4 mph

This is assuming 265/35-19 tires and achieving redline in each gear, which would be difficult in the top gears..... Looking at the extra ratios between 100-150mph in the DCT explains why it beat the 6MT by a full second to 200kmh....

[southlight]

http://www.m3post.com/forums/showthread.php?p=2087037


Best regards, south

[Big Windy]

208.4 mph for the DCT in 7th huh??? HAHA. DCT FTW I guess. I am still laughing at that.

[adamr]

this is all science fiction to me ... ill just choose to jump in the car and drive it and not worry about the math behind the gearing etc

[!Xoible]

Originally Posted by icemang17

Using this calculator I determined the speed in gears at redline 8400rpm for both M3's

http://www.autolounge.net/calculators/gearing.html

Heres the 6MT
1st 43 mph
2nd 73 mph
3rd 111 mph
4th 148 mph
5th 171 mph
6th 196.2mph

The DCT is:
1st 43mph
2nd 71mph
3rd 97 mph
4th 124 mph
5th 150 mph
6th 173 mph
7th 208.4 mph

This is assuming 265/35-19 tires and achieving redline in each gear, which would be difficult in the top gears..... Looking at the extra ratios between 100-150mph in the DCT explains why it beat the 6MT by a full second to 200kmh....

@ second gear!!!!!! 73 mph wow

i know 4th goes to over 145 coz i went to 145 when i redlined 4th gear. that was the best thing i've ever done

[JEllis]

of course there is no wind resistance factored in here correct? These are achievable speeds without drag correct?

Jason

[T Bone]

Originally Posted by Big Windy

208.4 mph for the DCT in 7th huh??? HAHA. DCT FTW I guess. I am still laughing at that.

7th gear is a lame fuel economy gear like the Vette Z06's 6th gear.

[!Xoible]

Originally Posted by JEllis

of course there is no wind resistance factored in here correct? These are achievable speeds without drag correct?

Jason

these numbers are not what speed will guarantee you will get to. it's the max speeds at which engine wont blow up when hooked to that particular gear. i dont know if im making sense, but not wind resistance isnt a factor.

[ersin]

Originally Posted by JEllis

of course there is no wind resistance factored in here correct? These are achievable speeds without drag correct?

Jason

No losses of any kind are factored in. This is the theoretical top speed in each gear at redline. The computer limits the top speed to 155 mph (or thereabouts). And if it didn't losses (drag, drive-train losses, etc.) would limit the speed in 6th, and 7th, probably.

[icemang17]

There is no resistance at all in the calculations......its pure gearing-RPM..there are some out there....but I can't seem to find one right now.....

But a 414hp car with a .31 drag and an effective frontal area of about 7.2 sq ft should be able to hit 190mph or slightly better....

[Sedan_Clan]

*subscribed*

[icemang17]

Originally Posted by PencilGeek

Unless you're suggesting that wind resistance will cause the wheels to loose traction and slip, MPH is a straight function of RPM, Gears, Tires, etc...not wind. Add wind resistance and sure your speed goes down...as will your RPM.

Am I missing something here?

No.....I just wanted to show what a stock E92 M3's different transmissions gear vs speed looked like....

When calculating top speed you need to account for aerodynamics (frontal area x drag = effective frontal area) available engine power and the gearing necessary to combine the peak engine power with the speed needed...... tire slip is another factor that could raise RPM higher that what is predicted for a given RPM....typically around 10% in most Open Road Racing scenarios....

I do think E92 M3's are capable of at least 190mph without limiters.....maybe right at the magic 200mph if the conditions were right....

[yoyeewee]

aside from all the scientific calculations on this post giving me all this information, i hope a magazine gets to test acceleration times of the 6MT and DCT side-by-side soon!

[footie]

If the M5/6 tops out at a true 205mph with 507hp then I would just the M3 M-DCT will struggle to get pass the 195mph mark, even on a slight downhill run.

No doubt swamp or Bruce will be able to prove through maths the exact figure.

[swamp2]

Originally Posted by footie

If the M5/6 tops out at a true 205mph with 507hp then I would just the M3 M-DCT will struggle to get pass the 195mph mark, even on a slight downhill run.

No doubt swamp or Bruce will be able to prove through maths the exact figure.

As far as I knew any M5/6 that breached a true 200 had mods.

The top speed of the E9X M3 from a theory/calculation and actual numbers attained has been extensively discussed in other threads. As a small aside with reported real world figures folks need to use a GPS, period.

[footie]

Originally Posted by swamp2

As far as I knew any M5/6 that breached a true 200 had mods.

The top speed of the E9X M3 from a theory/calculation and actual numbers attained has been extensively discussed in other threads. As a small aside with reported real world figures folks need to use a GPS, period.

I didn't know they had mods done, but then again that's the problem with Youtube videos and the likes, you are having to guage your beliefs on the honestly of the poster.

All I know is a S5 will comfortable posted a true 165mph on a GPS before the limiter kicks in. And as the M3 has more power, less weight, roughly similar drag and frontal area plus more efficient drivetrain, an M3 should be capable of a lot more than that.

[Simple1]

Originally Posted by swamp2

As far as I knew any M5/6 that breached a true 200 had mods.

The top speed of the E9X M3 from a theory/calculation and actual numbers attained has been extensively discussed in other threads. As a small aside with reported real world figures folks need to use a GPS, period.

http://video.google.com/videoplay?do...E4WEqgPvnuy3CQ

I beg to differ Swamp, granted he doesn't have gps!! but he has no mods, just the limiter removed! I've been on several runs with him, no mods.

[swamp2]

Originally Posted by Simple1

http://video.google.com/videoplay?do...E4WEqgPvnuy3CQ

I beg to differ Swamp, granted he doesn't have gps!! but he has no mods, just the limiter removed! I've been on several runs with him, no mods.

Uhhh, what part of BMW (and most manufacturers) having their speedos purposefully and lawfully 3-4% high have you missed out on? This is very likely right at 193.