7AT Faster 0-60 and 1/4 mile than 6 MT??
 

I keep hearing these claims over and over... Is there any thruth behind them?

I know that the 7 speed automatic transmission is pretty good, but are these claims right?

Yes, I do own a 7 speed... I know that if you want superior control over the car 6 speed MT is the way to go (all my previous cars were manuals) but this time around I had to compromise and opted for the AT.

Any input would be good to clarify this matter... :driving:

In magazine tests the AT is generally a little faster.

I think if you look at the time slip database, most of the faster times are by AT's.

Are the 7AT's faster, or quicker, or both?

That's full bolt-ons on a tire, though, from what I gather.

A good driver in a 6 speed will be faster.

Just more rapid.

+1

6MT with a skilled driver can launch much harder than a stock 7AT and should cut a quicker 60' time on a street tire, drag radial, or slick tire. The 60' alone will seal the deal in the 1/4 mile.

But on the average, stock for stock, the 7AT is quicker. This is mostly because not every 6MT driver can drive well enough to beat the 7AT. :)

At the end of the day, the 7AT and 6MT are so close, the driver will probably make the difference, as it does in most races.

The 7AT has shorter gearing so you stay a little more focused in the power band. You are also guaranteed a perfect shift every time which takes the human factor out of the equation. It takes a lot of practice to launch a manual with the perfect amount of slip off the line without going up in smoke or bogging down.

Drivers race but most of the 7AT's posted very low 13's stock 13.0-13.3

My self I posted 13.3 on my car when it was stock and only 3.5k miles



DAN

The fastest mag times in 0-60 and 1/4 mile times have been with the 7AT but the difference is only .1 sec by those who've done both. The fastest drag times at a strip for stock I've seen was also a 7AT.



edit: at Dragtimes, the fastest stocker is now a 6MT with the next 4 being 7AT's. Of course different tracks, track conditions, yada, yada, yada.......


http://www.dragtimes.com/compare2.ph...ame=Compare%21

That's amazing! I never thought I would see the day when an AT could seriously compete with a MT. Fantastic engineering on Nissan's part.

A lot of AT's are faster nowadays. I mean, it's part of why Ferrari is no longer going to make manual transmissions soon.

That's a common misconception nowadays. Most, if not all autos are faster than their manual counterparts. Manuals will eventually be phased out in favor of dual clutch setups as the tech gets cheaper.

Same with lambo's, most of the Mercedes AMG line as well. There's more of course there's no point listing them all.

The Ford Fiesta is getting a dual clutch automatic (next year?) so it's definitely getting there as far as affordability goes.

AT is fine, but torque converters suck. some kids are confused that torque converters are equivalent to electronic clutch AT's... which it isn't. it's not about just the shift speed, but how well the throttle and drive train is linked. slush box is very difficult to drive accurately for a MT driver due to the throttle slop. slop = not very sporty.

Another reason the 370Z 7AT is pretty good - full lockup can occur in 2 - 7 in M mode and partial lockup can occur in 2 - 6 in M and D mode.

:iagree::iagree:

If I'm not mistaking, the last time Ferrari had an automatic, torque-converter transmission like those found in the 370Z was the 456 GTA that ceased production seven years ago...
You can't compare a Ferrari transmission with an 370Z's AT

For you 7AT drivers who haven't tried the 6MT and syncro revmatch in the 370Z, I'll point out another thing.

If you're trying to accelerate hard with the SRM, it takes a bit longer if you're still trying to be smooth. The reason why is that when you let off the gas and press the clutch, the revs stay up until the point at which you actually select another gear. So if you want the revs to fall a bit for the next gear to be smooth, you're waiting another second or so for the SRM. Without the SRM, the revs would start falling as soon as you let off the gas and press the clutch.

Auto's may be QUICKER, but they are not usually faster.

The 3-pedal manual is here to stay, in my opinion, because some people like myself just don't get anything from twiddling at little levers with our thumbs. We like to stab the clutch.

The new automatics shift gears much faster than the old Chevy turbo 350's and 400's or 700r4's. The autos can shift fast then a person can move a gear lever. I am not talking about the dual clutch audi's and tech gizmo Ferrari's.

FWIW, I just plugged in some data on Z's listed as bone stock from the 1/4 thread and here's what I found: M (SD) N

MT: 13.67 sec (.07), 103.63 MPH (.40), 11

AT: 13.52 sec (.08), 104.62 MPH (.92), 9

That's leaving out the few clear high outliers for the stock MT's that were in the 14's BTW...

This is, again, also leaving out folks with bolt-on's, different gear sets, etc.

Anyway, close race, but the AT nudges out a bit faster, which is consistent with the findings of car mags.

Soooo... could a MT go faster? Probably -- but not on the average.

Yes, you are correct. ;)

The 7AT's are faster on average because of the quick consistent shifts and the great gear ratios. Their downfall is the low stall speed of the torque converter.

The 6MT's have the advantage at the launch (at the track). At the track, I'm usually launching at 4000 to 4500 RPM, results = 1.8x and 1.9x 60ft times with stock tires.

I have a torque converter on the way 2900 to 3000 rpm stall. Stock converter spins the wheels at 1500 rpm.
it should cut 1.8 ???? 60 ft times.
Z

Thanks to everyone for their input. It does seem that the 7AT is faster overall. Nice to know...

Could someone provide more details into the AT transmission? I thought that it was a dual clutch...

Let the information flow continue...:driving:

It's not a dual clutch. It's a typical slush-box with a torque converter. It's just better than most every other slush-box out there.

Just be advised that if you want to go FI you should get the MT. The 7AT is very limited in how much power it can handle and, as of now, there's not much readily available to help it hold more power. From the factory it is rated to a maximum 298 lb-ft, and recently we had one grenade that was pushing only 350 lb-ft via supercharger.

The 6MTs are rated to 332 lb-ft from the factory but with a clutch/flywheel upgrade they can take a good bit more.

I was talking about AT's in general, br0. Just saying that the tech exists to make them faster than manual. Tha's all.

Not exactly. It also has full lock up for a solid connection in 2-7 gear, which means significantly better power transfer. That's why the two trans put down about the same numbers on the dyno.

Traditonal slush boxes are just that -- they only allow fluid coupling (or only have lock up in the tallest gear).

Moroever, if memory serves, Nissan tuned it to accomplish gear changes in < .5 sec under load.

Lol, Ford, GM, and everyone else had that in the mid/early 90's. In the crown-vic, mustang, etc. It's nothing new.

Slushbox.

Lock up in every gear after 1st? News to me, but okay.

If I wanted to have the feel of driving my car taken away I'll play forza motorsports.

yes, usually its lock-up in high gear only on typical american cars.

Not only that, but the 7AT lock up begins at 15MPH which is considerably lower than most, and has lock up at all throttle positions, not just WOT.

The biggest issue I have with the current 7ATs is that they are fragile when compared to the m6. Forced induction for the vq37 has made leaps in the past year. Soon it will be safer, easier to install, godwilling tuning will advance, and it might even get cheaper. However all you AT guys will have to spend the extra money on valve body upgrades and torque converters. I personally know of one G transmission that bit it with a tt and shumby's transmission just went as well. So sure you can make all the 7AT arguments you want but when it comes down to it the m6 is more durable in the hands of a smart driver and more able to withstand the tq increases we're all chasing.