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2003-2009 Nissan 350Z

How's the MT compared with the AT?

Old Aug 4, 2004 | 08:53 AM
  #21  
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Originally posted by Sileighty_180sx
Thanks guys

Actually I wont consider the Automatic Transmission at all for the 350z, because to me I think manual has more control somehow. (I don't know how to explain it, but that's what I feel.) For example, like I can shift from 4th to 2nd with manual within a second and for the Automatic, the computer wont allow me to do that.

The AT tranny in the 350Z allows you to shift from 4th to 2nd in manumatic mode by clicking down twice in quick succession (I don't have an AT, I drive a 6MT but that is what I heard from our AT brothers).

The 350Z is my first MT car, and let me tell ya its quite fun! But the AT is also quite capable. The reason I wanted a 6MT is because I wanted to give it a try. Either tranny is a good choice, you can't lose.

And since I am a manual newbie, I can pretty much guarantee that 100% of 350Z AT drivers will beat me

Like others have said, give both a try and see which one you prefer.
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Old Aug 4, 2004 | 11:13 AM
  #22  
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I didn't think about that. There are many times during my commute that I blast through 1st and 2nd gear only to slow down due to traffic, etc etc, and shift it into 6th gear.

1-2-6 shift in 6MT
vs
1-2-3-4-5 with three "upclicks"

Definitely not as natural.
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Old Aug 4, 2004 | 11:39 AM
  #23  
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Originally posted by Aggro_Al
95%!!!! It's 100% faster than all the manuals out there in the more aggressive profiles.

Show me a driver who says they can shift a manual tranny faster than the tiptronic or sequential trannies, professional or otherwise, and I will show you someone who doesn't know what they are talking about and/or are full of BS. It is possible for a human to pick better shift points but they are not faster shifting. The new tiptronic and sequential shifters can shift in the milliseconds.

Just for reference:
Average human eye blink: ~300ms
BMW SMGII: fastest shift speed: ~80-70ms
Porsche Tiptronic S: adaptable middle profile: <200ms(varies depending on input sensors)
Ok, i'm not gonna argue the numbers that you posted, i just want to clear up one thing. A tiptronic is just an automatic transmission that lets you select the gear. you choose the gears in a sequential manner but there is still a torque converter.

Sequential transmissions on the other hand are TOTALLY different. They are in fact cluctchless manuals. They have no torque converter.

Having said that, bmw's smg and ferrari's sequential trannies can shift quicker than a person can, however they add slightly to the weight of the car if I'm not mistaken. They also are not as fun to drive because let's face it...you gotta have the clutch!!

As far as comparing them all: sequential is the fastest shifting, manuals are next, and tiptronics are the slowest. no a person cannot shift faster than sequential, but yes a person can shift faster than tiptronic. Furthermore, because of the presence of a torque converter in a tiptronic, the driveline losses (the difference between 287hp and the whp of a stock car from a dyno) are greater, and therefore the whp of a manual/sequential will be greater than the whp of an automatic.

There is no way that an automatic 350z will be faster than a 6mt. The assumption there is that the 6mt driver is a good driver and does not mis-shift. The automatic is more fool-proof, but assuming good shifts in the manual there is no way the auto will beat it...
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Old Aug 4, 2004 | 01:46 PM
  #24  
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Originally posted by genieman17
Ok, i'm not gonna argue the numbers that you posted, i just want to clear up one thing. A tiptronic is just an automatic transmission that lets you select the gear. you choose the gears in a sequential manner but there is still a torque converter.

Sequential transmissions on the other hand are TOTALLY different. They are in fact cluctchless manuals. They have no torque converter.

Having said that, bmw's smg and ferrari's sequential trannies can shift quicker than a person can, however they add slightly to the weight of the car if I'm not mistaken. They also are not as fun to drive because let's face it...you gotta have the clutch!!

As far as comparing them all: sequential is the fastest shifting, manuals are next, and tiptronics are the slowest. no a person cannot shift faster than sequential, but yes a person can shift faster than tiptronic. Furthermore, because of the presence of a torque converter in a tiptronic, the driveline losses (the difference between 287hp and the whp of a stock car from a dyno) are greater, and therefore the whp of a manual/sequential will be greater than the whp of an automatic.

There is no way that an automatic 350z will be faster than a 6mt. The assumption there is that the 6mt driver is a good driver and does not mis-shift. The automatic is more fool-proof, but assuming good shifts in the manual there is no way the auto will beat it...
How fast have you shifted a manual tranny? I highly doubt that you can shift faster than an eye blink. I think that most drivers MT and AT will concur on that. The reason that the tiptronics and sequentials can do it that fast is because they don't have a manual clutch pedal. They both use computerized electronic clutches.

The tiptronic type transmissions do use torque converters but, they are not totally different from the sequential transmissions. The sequential transmissions and tiptronic transmissions are very similar. The biggest difference, as you pointed out, is the use of a torque converter vs friction plates as the method of power transfer. Except for some minor software differences they both operate the same.

Yes, you are correct that the sequential shifters don't use a torque converter but, the sequential shifters are not clutchless manuals. Only transmissions that have a manual clutch and manual shifting are manual transmissions. The other types at best are automatics with manual overrides. Sequential shifters don't have manual clutches, they have electronic clutches. With a tiptronic in manual mode or a sequential in manual mode, you only get to choose the time you want to shift. Once the shift command is input the computer handles the whole shifting process. You don't get the ability to actually shift like in a real manual. With the exception of the Toyota SMT, I think that most sequential shifters have the ability to shift on its own without input from the driver just like a standard automatic. BMW in their dealer manual describes the SMG as an "all-automatic manual gearbox w/active manual shift select". They describe the SMG as an electronic, fully automated transmission using the parts of a manual gearbox instead of a torque converter. It's an automatic transmission that uses electronics and computers to automate the parts of a manual gearbox. Just because it uses the parts of a manual gearbox doesn't make it a manual transmission. Giving the driver the ability to manually choose when to shift also doesn't make it a manual transmission because the computer still does the shift for you. The most familiar sequential shifter, the Ferrari F1, is more automated than the Nissan 5AT. The Ferrari F1 in manual mode will upshift if you reach the rev limiter. The 5AT in manual mode will not shift until you tell it to shift.

On a dyno the 6MT is more efficient at the higher RPMs. It will put down about 3-5% more horsepower than the 5AT. The 5AT in 4th and 5th gears use a lock-up clutch which basically makes the torque converter a direct connection like the 6MT. The 5AT because of the torque converter is better at torque management in the low to mid RPMs than the 6MT. A torque converter can create more torque than the engine is outputting. There are several variables as to why the 5AT has less horsepower than the 6MT. One of the biggest reasons is the final drive ratio. The 6MT also uses friction and pressure plates which is slightly more efficient that a locked torque converter. In the real world, at the speeds and tracks that most races occur on you probably won't notice a 3-5% difference.

I like the 6MT. It's fun to drive. As far as the Z goes, there really isn't any performance advantage with either the 5AT or 6MT. In the Z, like so many have said before, it is just going to come down to personal preference. I don't know everything about transmissions but I do know enough to know that there are quite a few misconceptions of transmissions of all types. Just trying to keep things real.

Last edited by Aggro_Al; Aug 4, 2004 at 02:12 PM.
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Old Aug 4, 2004 | 01:51 PM
  #25  
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Originally posted by genieman17
There is no way that an automatic 350z will be faster than a 6mt. The assumption there is that the 6mt driver is a good driver and does not mis-shift. The automatic is more fool-proof, but assuming good shifts in the manual there is no way the auto will beat it...
I would go race a 5AT 1st if I were you before I made that assumption. I'm not bashing you, I'm just asking if you have any experience with the 5AT before you go saying "There is no way "
Take it from me, I have a 5AT. Plus I have owned 4 other Z's through the years all MT's the last being a turbo. That said, my 5AT is just as fast if not faster and I wouldn't be afraid to go against any 6MT no matter whos behind the wheel. Thats how confident I am with my AT. Even if I don't win them all, they all will be very,very close.
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Old Aug 4, 2004 | 02:37 PM
  #26  
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Dude. Aren't the official MT times faster?
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Old Aug 4, 2004 | 02:56 PM
  #27  
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Originally posted by DragonGcoupe
Dude. Aren't the official MT times faster?
Where are those official MT vs AT times? I'd like to see the official statement because there are almost no professional reviews of the 5AT 350Z. An official statement from Nissan saying that the 5AT is definitely inferior to the 6MT would be very helpful in ending these MT vs AT wars. Please post a link so that we can all see it.

Thanks
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Old Aug 4, 2004 | 03:27 PM
  #28  
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Originally posted by Aggro_Al
Where are those official MT vs AT times? I'd like to see the official statement because there are almost no professional reviews of the 5AT 350Z. An official statement from Nissan saying that the 5AT is definitely inferior to the 6MT would be very helpful in ending these MT vs AT wars. Please post a link so that we can all see it.

Thanks
Aggro, I wrote to Sport Z Magazine a couple weeks ago in reference to that very subject. I asked, due to all the controversy on this forum and others about the 6MT vs. 5AT would they consider taking a MT & AT and put them up against each other in a road test. I even suggested throwing in a 6MT Roadster due to the weight disadvantage. 1/4 mile, 0-60, skid pad, and road course times. Needless to say I never heard back from them. Would have been interesting reading don't you think ?
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Old Aug 4, 2004 | 03:37 PM
  #29  
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Sure would be interesting reading.
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