G37 Coupe

7AT vs 6MT acceleration

Thread Tools
 
Search this Thread
 
Old Apr 17, 2010 | 05:44 PM
  #31  
Creepers's Avatar
Creepers
Registered User
 
Joined: Jan 2010
Posts: 362
Likes: 1
From: philly
7AT
Old Apr 18, 2010 | 02:39 AM
  #32  
The Jewbag's Avatar
The Jewbag
Registered User
iTrader: (1)
 
Joined: Oct 2008
Posts: 938
Likes: 0
From: Jew York
Maybe you guys baby your cars too much. These cars are meant to be driven.
Old Apr 19, 2010 | 12:30 AM
  #33  
LSUtigerME's Avatar
LSUtigerME
Registered User
 
Joined: Jun 2008
Posts: 51
Likes: 0
From: Baton Rouge, LA
This thread got me curious, so I decided to run some theoretical numbers on each. I was curious if the taller gears in the 7AT would have some benefit to the 6MT. Since the thread's main concern (ie. the OP's question) is only for acceleration, this simulation has some merit.

The assumptions:
- Shifts are equal in length and number (1st through 5th), effectively within .050 secs (the calculation step). This could leave some room for debate, but I was more interested in the gearing. Also, since they shift at different times, any additional shift length at a higher speed could have a greater effect due to drag. I'm simply assuming this is negligible in difference (not effect).
- Torque values are based on dyno numbers from a 6MT only. I could not find any information for a stock dyno from a 7AT. Dyno used is HERE. I adjusted this by adding an additional 5% loss in the 7AT geartrain.
- Weights are assumed equal.
- All ratio data, drag coefficient, frontal area, weight, etc. are pulled from HERE
- Starts at 17 mph due to dyno begins at 3k rpm (17 mph = 1st gear at 3k)


Name:  G376MTvs7AT-Equal.jpg
Views: 2191
Size:  34.4 KB

Name:  G376MTvs7AT-95Efficiency.jpg
Views: 2267
Size:  34.8 KB

Conclusion:
So, as you can see, they are damn near equal for all intents and purposes. The taller gearing in the 7AT gets it out front early, but it's eventually overtaken by the 6MT (around 120 mph in equal efficiency, 100 mph in 5% loss). The 6MT probably traps a little higher, but their times are nearly identical. Interesting outcome, but not necessarily suprising.
Old Apr 19, 2010 | 01:24 AM
  #34  
Mike's Avatar
Mike
Registered User
iTrader: (1)
 
Joined: Feb 2008
Posts: 4,549
Likes: 20
0.05 S shift on a 6MT? That's impossible

Just giving you a hard time.
Old Apr 19, 2010 | 01:53 AM
  #35  
blaque831's Avatar
blaque831
Registered User
 
Joined: Oct 2007
Posts: 70
Likes: 0
My $.02: Just came out of a 6MT for 2 years and into a 7AT for about a month now. I do a lot of city driving, and the 7AT feels much faster. Maybe I just wasn't that aggressive of a driver in the 6mt, but I'm very impressed with the 7AT. Butt dyno tells me 7AT = better. Even at 26 y.o., but maybe I'm tired of shifting.
Old Apr 19, 2010 | 03:58 AM
  #36  
Skyline73's Avatar
Skyline73
Registered User
 
Joined: Nov 2009
Posts: 33
Likes: 1
Originally Posted by Ender17
I've been searching for the last 30 minutes or so trying to find a definitive answer as to which transmission is faster for the couple.

7AT or 6MT? I know the consensus that they're really close, but I haven't seen any direct comparisons. Maybe I just suck at searching, but if anyone has actual test data, I'd be most appreciative. Thanks!
You must not like to read because many magazines have tested both versions. The answers you are getting here as well prove other owners are about as naive as you. The autos have ranged between 4.9 and 5.2 to 60. The manual about 5.0 to 5.3. Both reach the quarter in the same exact range of 13.4-13.7.
Now let me ask you? What's the hooplah over .01 seconds or even .03? What are you buying this car for? Do you just want to brag to your friends you have a sub 5 second car? If you want any kind of real power you have to mod. When a stock car is in a .05 second range of another cars acceleration... once modded they are in the same ballpark. So I don't get what your obsession is with .01 seconds faster? You want to go faster??? Buy a Z. It reaches 60 in 4.6 to 4.9 sec? Not fast enough for you? But a vette... it goes to 60 in 4.0 seconds. Make your threads meaningful dude
Old Apr 19, 2010 | 04:17 AM
  #37  
oro's Avatar
oro
Registered User
 
Joined: Nov 2007
Posts: 192
Likes: 1
From: Gilbert, Arizona
"Feeling faster" Is all in the torque delivery and shortness of the gears. Honda S2000's don't "feel" like they are going fast at all but their acceleration is actually up there, but their lack of torque is deceptive. Same goes with the E46 M3.

I could drive the crap out of my 350Z when I had it and it would "feel" faster than my buddies E46 M3. I drove both and my quarter in the M3 although it didn't feel as fast was much faster than my Z.

I have a 2010 37 sedan I'm using right now as a loaner my 08's master cylinder just died. The car does feel faster due to the shortness of the gears, it feels like you are rowing through gears faster which gives the illusion of an immense difference in acceleration. I guarantee if you roll race a manual 37 it will be virtually a dead even heat though.
Old Apr 19, 2010 | 04:18 AM
  #38  
Mysticalism's Avatar
Mysticalism
Registered User
iTrader: (1)
 
Joined: Mar 2009
Posts: 569
Likes: 1
From: Vancouver, B.C.
what ever it is man, i just got my *** smoked by a camero SS lol, that car pull faster than chuck norris dood
Old Apr 19, 2010 | 04:21 AM
  #39  
oro's Avatar
oro
Registered User
 
Joined: Nov 2007
Posts: 192
Likes: 1
From: Gilbert, Arizona
Originally Posted by Mysticalism
what ever it is man, i just got my *** smoked by a camero SS lol, that car pull faster than chuck norris dood
Yeah feeling faster doesn't equate to *being* faster with an 100hp/tq advantage.
Old Apr 19, 2010 | 05:05 AM
  #40  
Skyline73's Avatar
Skyline73
Registered User
 
Joined: Nov 2009
Posts: 33
Likes: 1
Originally Posted by oro
Yeah feeling faster doesn't equate to *being* faster with an 100hp/tq advantage.
I rented the camaro. It feels slower than my G though I know its much faster. But the camaro really takes up over 100mph. The torque is just riculous up in the 100+mph range
Old Apr 19, 2010 | 09:48 AM
  #41  
Mike's Avatar
Mike
Registered User
iTrader: (1)
 
Joined: Feb 2008
Posts: 4,549
Likes: 20
Originally Posted by Skyline73
I rented the camaro. It feels slower than my G though I know its much faster. But the camaro really takes up over 100mph. The torque is just riculous up in the 100+mph range
Its all about HP.

Try sitting in a 600+ft/lb diesel truck. It'll FEEL super fast.
Old May 11, 2010 | 04:54 PM
  #42  
MSCA's Avatar
MSCA
Banned
iTrader: (3)
 
Joined: Aug 2005
Posts: 1,474
Likes: 1
Originally Posted by demuslee
I've read somewhere that the 7AT in the DS mode is faster than the 6MT because the computer shifts at the optimum RPM..
That's weird logic. I guess 6MT drivers aren't able to shift at the optimum RPM?
Old May 11, 2010 | 11:52 PM
  #43  
dainjarouz's Avatar
dainjarouz
Premier Member
iTrader: (4)
 
Joined: Nov 2009
Posts: 715
Likes: 3
From: SoCal
when i was looking for cars..one of the infiniti dealerships told me "the auto is faster in 0-60" and i thought that that was so IRRELEVANT. come on dude!
Old May 13, 2010 | 01:57 AM
  #44  
SpartanG37S's Avatar
SpartanG37S
Registered User
iTrader: (1)
 
Joined: May 2010
Posts: 692
Likes: 2
From: Hampton Roads, Virginia
Acceleration? Really? .1 of a second is a driver's race. Mag racing has become a disease, and it's starting to spread.

Different strokes for different follks, but when a manual transmission is available, I ALWAYS go for the manual.

I carve mountains once a month in my G37, and it's much more engaging with the manual. I taught the wife how to drive a manual years ago, and even drive with the best of them. I taught her how to rev-match and all
Old May 16, 2010 | 01:49 AM
  #45  
Nick3753's Avatar
Nick3753
Registered User
 
Joined: Feb 2005
Posts: 169
Likes: 2
A bit off topic, but does the 6MT rev match like in the 370z (I don't see anything advertised as such). If not, any idea y not.



All times are GMT -4. The time now is 03:44 AM.