ZlleH

iTrader: (7)

Just so I can get your definition of a "sports" car right... You mean to tell me that a true "sports" car in your opinion is one that doesn't have a 25% drivetrain loss as oppossed to the manual loss of 15% on the drivetrain?

Because that is what I am getting when you say it is not about buttons/paddles/or tiptronic technology. All you care about when defining a true "sports" car is that the manual has a 15% hp loss instead of an automatic 25% loss?

Dream

Really, you ought to summarize this in future posts when you complain about ATs in sports cars. Something like

It explains your position more clearly than

RPM_204

A mistake by Nissan? J/K...

In actuality, offering an AT ensured the Z would appeal to a broader audience. Hence contributing to the sales success of the Z...

Aggro_Al

There is no such thing as a clutchless sequential shifting transmission. All multigear transmissions have at least one clutch. The 5AT has at least six clutches. The clutch is what allows two or more different shafts moving at different speeds to engage or disengage. The clutch is what allows us to have multiple gear ratios in the same gearbox. F1 cars do have a manual clutch paddle that they use to manually disengage the transmission during starting, in the pits and in an uncontrolled spin. This clutch paddle isn't used for shifting, though.

The only cars I feel that get to be called manual transmissions are the regular standard transmissions where the driver manually controls both the clutch engagement and the shift change. The 5AT in manual-mode allows the driver to shift on demand at anytime like the F1 transmission but I wouldn't go calling either one of those a manual transmission. At best, I would describe them as semi-automatic because you still get to choose when to shift even though you don't do the shift.

There are vehicles that don't use a manually operated clutch. But,I'm not aware of any mainstream multiple gear transmission used in a car that doesn't use at least one clutch, be it manual or automatic. All the available sequential shifters (F1 Type & Tiptronic Type) that I'm aware of all use computer-controlled automatic electro-hydraulic clutches and use computer-controlled automatic shifting. The driver only gets to choose when he wants to shift. The computer controls the whole shift process, everything from the clutch operation to the gear change.

There is one type of transmission being developed called a ZeroShifter that can use multiple gears and can transfer torque continuously without power breaks like a CVT. It's also non-sequential so you can be in any gear at anytime without having to go through the other gears in order. It uses an automated spring and bullet system as the clutch instead of a manual friction plate clutch but, specific details on the actual system are still under wraps.

If you know of any F1 or Tiptronic type sequential shifter that isn't automatically controlled by a computer I'd be very interested in learning more about it. I would like to see how they got the clutch to operate and how they changed gears.

Amnbex

Actually, when the 350Z was tested around the Nurnburgring (you know, that really big track with 13 miles of turns) by journalists for a big japanese car magazine (the name escapes me atm, I would have to search for it) the 5AT actually came in 1 second ahead of the 6MT while in full auto mode because the auto mode allowed the driver more concentration on picking the best line through a corner.

However, that is a stupid argument as a barely modified Miata will fly by both the 5AT and the 6MT trying to duel it out.

Of course, I myself prefer the 6MT and in all cases prefer a manual transmission. I would never ever ever ever ever ever ever ever ever EVER purchase a Ferrari with the F1 sequential transmission (if I ever had the chance, hah!) or a sports car with an automatic.

That said, there is no performance difference, so if you don't like the clutch, you're not losing ANYTHING at all by not getting it, despite what fanboys and idiots say.

Amnbex

Are you stupid or do you just open your mouth to make people think you are?

Each of those mechanisms you mentioned, starting from the DSG gearbox by Audi to the F1-style transmission available in an Aston Martin, Ferrari or Maserati has an automatic mode.

Let me repeat that, because you seem to be unable to understand the most simple of points: every "semi-manual" transmission has a full automatic mode where the shifts are not controlled by the driver, but by the internal computer. Just like the 350Z.

The BMW tranny? Yes, it has an automatic mode.
The Ferrari F1-style tranny? Yes, it has an automatic mode.
The Maserati "sport-shift" F1 sequential? Yes, it has an automatic mode.

In fact, having actually driven one of those dismal contraptions they call the BMW SMG I would say that I would take the 5AT in the 350Z any day of the week. Seriously, the SMG is one of the worst transmissions I have ever had the displeasure of driving.

That said, I will reiterate that I do prefer the manual, but not for any performance reasons, I just like the clutch.

Aggro_Al

Yup, you're correct F1 cars do use sequential gearboxes. But, any transmission that uses paddles, levers, buttons, etc. in a 1 2 3 ... 3 2 1 shift sequence is a sequential gearbox. That is how it got it's name. A gearbox that allowed you to be in any gear at any time is a non-sequential gearbox.

Never said that F1 cars used torque converters because they don't. The F1 shifters use the same exact gearbox as a regular manual but use electronic controls to automate the shift process. And yes they do use fluids in F1 trannies. You mentioned it yourself, "hydraulic-actuated clutches and shifter". The last time I checked "hydraulic" means fluid based.

Both the F1 and Tiptronic type sequential shifter operate similarly. They both use automatic clutches and the shift process is automatic. The only real difference is how the power is transferred to the driveshaft. F1 uses friction plates and Tiptronic uses a torque converter.

Aggro_Al

Where's the extra drivetrain loss at? Both the 5AT and the 6MT have similar drivetrain losses. If we use an enthu MT and an enthu AT as comparision, they have the same engine and drivetrain, the same wheels, 5th gear on the 6MT and 4th gear on the 5AT have the same drive ratio and no fluid loss from the locked TC. Put both cars on the dyno and the difference is caused by the different sizes in the final drive gear, not by parasitic losses in the transmission.

The 5AT uses full lock-up clutches in 4th & 5th gear and a partial lock-up in 3rd. The impeller and turbine are locked together mechanically. There is no fluid loss when the torque converter is locked.

The 5AT also has a stator rotor in the torque converter that can create more torque and multiply the torque coming from the engine when torque converter is unlocked or uncoupled.

What lag are you talking about? The 5AT can shift faster than any human can. Just look at the numbers.

Audi DSG: ~20ms
BMW SMG II: ~80ms
Ferrari F1: ~150ms
Porsche Tiptronic S: <200ms (varies because it is an adaptable transmission)
Human Eyeblink: ~300ms
Professional NASCAR Driver: ~0.8second
MT Fanboy: Ludicrous Speed

If you can shift faster than a NASCAR driver let alone the 5AT, let me be your agent on the racing circuit. We can make some serious money.

nbdyfcnsqnc

>> In my honest oppinion the 5AT is a great option for stop and go traffic or long trips where you get fatigued.

I've driven over 1000 miles in one sitting on four occations, and drive in heavy traffic almost every day. No complaints here except maybe the stupid T-shape of the steering wheel.

Unscientifcally, I do think the AT's are more reliable by far, and I think the MTs have a combination of problems both from the factory and from irresponsible use based on the stories I've read. Mine was swapped at 17k, and I'm sure I didn't do anything wrong with it.


>> How about formula 1 race cars? They use paddles/buttons with no manual clutch for their gear shifting. Maybe you should go challenge them. I'd love to watch you challenge their non-manual racing.

Those use electronic clutches. It gives you faster gear switches, but costs the extra dimension of control the clutch affords you. So while it can help your times in some situations, I doubt it would be as fun to drive on the street.

zipgun

Hell I always say screw whatever peeps say, get what ya want its your money, AT's arent sports cars? HA! yeah whatever, like I care what someone says about what I drive

Anyway, I love the MT trans in our Z, very peppy and loads of fun, but I also love my tip 996 4s coupe much more, just love the paddles and wish the Z had em too, the Z is mostly my wifes car, but she has no issues either way. I dont see much of a performance loss esp with todays newer adapt-trans, we've only owned mt's cars in the past including a 993 coupe and 1st and 3rd gen rx7, so were not alien to mt's or lazy We do have one bias tho, no 4dr cars, never ever

ZlleH

iTrader: (7)

You assume we are not having as much fun as you are? Isn't that being a little arrogant? What makes you think we have to like what you like to have as much fun as you do?

Don't want to sound mean, but really, think about it...

Fully automatic only goes on when I am in traffic jams going back and forth from work. Every other time, I have it on tiptronic.

SteveZ33

Thanks for this info Amnbex ! I have been waiting to see a 5AT vs. 6MT performance comparo. I even tried to talk Sport Z Magazine into doing a performance (non bias) "shoot out" when they were asking for article ideas for future issues. I would love to see the article that you mention above. Where did you see it ?

Low J.

When I say "clutchless" I mean that the driver doesn't have to operate a clutch.

Low J.

Sorry you're wrong.....an automatic tranny with a torque converter usually has somewhere between 20%-25% drivetrain loss compared to a manual. The HP and torque is the same of courese because the engine is the same but the AT cannot put that power to the ground as good as the MT.

Low J.

What on earth makes you think I don't know this......

Low J.

Faster shifts do not make up for drivetrain loss. When there are systems (like the DSG) that are supposed to not only shift faster than a person but also use a pre-selected clutch setup that gets rid of the torque converter loss then I'll go with that any day. Traditional automatics that just let you choose when to shift will still not perform as well as the manual....this is why any road tests you read will have better performance numbers from the manual as well as better fuel economy.

Low J.

If you're talking to me I never said that.

Skrill

[QUOTE=Aggro_Al

Both the F1 and Tiptronic type sequential shifter operate similarly. They both use automatic clutches and the shift process is automatic. The only real difference is how the power is transferred to the driveshaft. F1 uses friction plates and Tiptronic uses a torque converter.[/QUOTE]

If you really believe that you are hopeless. Do some more researchon F1 trannys. They are so far from our Tiptronic it is not even funny. And no -- they do not operate similarly.

BTW, F1 drivers and actuate the clutch manually from a lever that sits behind the steering wheel. It's what they use to launch away from the line and pit stops.

Skrill

Setting asside the one test on the ring and your thoughts (I am sure you have see the video of Hans Stuck getting around the ring just fine in a stick shift M3 GTR). BTW, I am highly doubtful of the legitimacy of that test. ATs definately are not setup for track driving. Their response to input input is slow. And they don't allow for heel-toe.

And one thing you cannot deny -- with 6MT you get a better final drive and better, closer gear ratios (due to the extra gear) resulting in better acceleration and better lap times.

Full stop ... no more need for discusion. The gearing alone makes the 6MT superior for performance driving.

Aggro_Al

See above, the 5AT uses a lock-up clutch. The clutch is a mechanical clutch. There is no hydraulic loss on the 5AT when the clutch is engaged.

The 5AT uses a real-time driver and environmental adaptable clutch set-up. It is always monitoring and adjusting the clutch and shift. There is no need to use a pre-selected clutch set up. It is more advanced than the one's you have to pre-select.

On the Z, the 6MT and the 5AT have similar losses. The difference you see on the dyno is caused by the size difference in the FD. 6MT has a 3.5 gear and the 5AT has a 3.3 gear. Based on the difference in FD size the 6MT should put down 4-6% more hp which is about the difference that most people get. If they had the same FD, they would be very close.