Why the AT7 is quicker than the MT6
#1
Why the AT7 is quicker than the MT6
Last week, I took at 2012 G37x for a test drive. I was curious to see how much different the 6MT was compared to the AT7 in power and handling.
Most of you already know this, but the AT7 is a great transmission! It shifts very well and the "rev match" feature makes everyone look like a hero. Maybe it was just this G37x, but the intake had a nicer sound (little louder) than my MT6. I checked the air filters, and they were not K&Ns, but also were not made by Nissan.
Leaving a red light the car felt VERY quick, quicker than mine. I wanted to understand the gearing differences, so I put this graph together:
(Solid line: MT6 / Dashed line: AT7)
The auto puts down about 500 MORE foot-pounds of torque at the contact patch in first gear. Second gear is about 450 MORE foot-pounds of torque.
With LOTS more torque at the drive wheel(s), only a slight (100ish pounds) weight penalty of the AWD, and VERY quick shifts I now understand why it is faster.
NOTE: The graph is based from a single dyno done by Automobile Magazine and does not reflect any additional losses in the AT7 transmission.
By the way, the shift points for maximum drive wheel torque are at 7500 RPM, for all gears.
Most of you already know this, but the AT7 is a great transmission! It shifts very well and the "rev match" feature makes everyone look like a hero. Maybe it was just this G37x, but the intake had a nicer sound (little louder) than my MT6. I checked the air filters, and they were not K&Ns, but also were not made by Nissan.
Leaving a red light the car felt VERY quick, quicker than mine. I wanted to understand the gearing differences, so I put this graph together:
(Solid line: MT6 / Dashed line: AT7)
The auto puts down about 500 MORE foot-pounds of torque at the contact patch in first gear. Second gear is about 450 MORE foot-pounds of torque.
With LOTS more torque at the drive wheel(s), only a slight (100ish pounds) weight penalty of the AWD, and VERY quick shifts I now understand why it is faster.
NOTE: The graph is based from a single dyno done by Automobile Magazine and does not reflect any additional losses in the AT7 transmission.
By the way, the shift points for maximum drive wheel torque are at 7500 RPM, for all gears.
Last edited by SonicVQ; 04-27-2016 at 12:06 PM.
#4
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#5
In Ontario, we have street racing laws where if you exceed the limit by 50 KPH (31 MPH) they take your car AND you loose your licence ON THE SPOT for a week, PLUS $2,000 - $10,000 fines.
#6
I think we can all agree that automotive technology has reached a point where computers are infinitely more capable than humans when it comes to going from point A to B more quickly and more efficiently. Even if the gearing were the same, I'd always put money on an AT because of the inherent lag in manual shifting. If these graphs are truly reflective of all G's, it's pretty obvious which one you would rather race with. However, purists will always side with the third pedal because it enhances driver engagement and it's a timeless tradition that many people don't partake in these days.
/rant
/rant
The following 3 users liked this post by kickintheglass:
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#8
If you did over 30 above the speed limit in NJ, you'd have so many points that you might as well not drive for a few years
#10
I kind of hated my s2k because by the time I shifted into second I was doing over the speed limit. So just driving it easy sucked. But that's another story. I would have loved to have gotten a 6mt in my G but I didn't have many options. And I'm happy with just hitting the gas anyways. Something to be said for just point n shoot.
#12
#13
Autos still have more drive wheel torque:
- First gear by about 250 foot-lbs
- Second gear by about 300 foot-lbs
- third gear is about the same
All calculations are assuming the auto is as efficient as the manual, which is is not.
Automatic transmissions are around 85-88% efficient and manuals are about 96-97%.
#14
#15
Most high performance cars these days are going with automatics because they are more efficient and out perform a clutch pedal and shiftier. People can bag on automatics all they want - but its the way of the future. Manuals are slowly being phased out
Especially the newer dual clutch automatics that can shift in a blink of an eye.
I am very happy with my 7AT it is very smooth and the tiptronic shifting is fun for when I want to drive like a maniac. I do wish the DS mode had different shift point and held lower gears for longer so its ready to pull. Does anyone know if this is programmable or how I go about this?
Especially the newer dual clutch automatics that can shift in a blink of an eye.
I am very happy with my 7AT it is very smooth and the tiptronic shifting is fun for when I want to drive like a maniac. I do wish the DS mode had different shift point and held lower gears for longer so its ready to pull. Does anyone know if this is programmable or how I go about this?