Automatic Transmission ND

[KevGoat]

My SE will be the last manual I'll ever own, even if we move on to an ND sometime in the future. I wasn't even going to have another manual MX-5 when I bought this one, but I'd yearned for a Velocity Red SE for a long time and couldn't resist. Definitely no regrets, but I'm over shifting gears ...

[Mr nanotech]

It's there so people with disabilities and elderly people who struggle operating a clutch due to aging are not alienated from the market.
It isnt ideal but at least these people have an option to own and drive the car in automatic form. Also boosts sales with lazy people who just want to cruise in something pretty.

[97 MXV]

To me the issue is not whether it is auto or manual, the issue with the ND is 人馬一体.
How at one the driver can be with the horse ? Does it pass the 人馬一体 Test ?
Some get 人馬一体 with a manual.
Some get 人馬一体 with an auto.
Now on NA and NBs it was clear cut, the auto won the Hairdresser's Choice hands down.

However, modern paddle shift autos with lock up clutches, 6 speeds or more, and controlled throttle downshifting are literally there 人馬一体 wise, provided the ergonomics of the paddles verses lock to lock of the steering is done right. (Paddles are hopeless unless the steering ratio is very direct)

The issue with the ND in my book is the transmission/diff gearing of the 1.5 ND does not pass the 人馬一体 Test.
On the 1.5 ND, Mazda provided a Knocker engine gearing behind a Screamer engine with a 7500 rpm redline...so wrong and clearly a lost 人馬一体 opportunity.
Compared with the 2.0 ND, the only thing a 1.5 ND has going for it, is its revs.
It has 7500 of them, and at only 1.5 litres, every rev is precious.

Checkout the ratios.
The gearing is just too high for a 1.5 Screamer engine.....人馬一体 Test Fail !
The fractional improvement they achieved in the Highway Fuel Number won't Save the Planet.

Now if Manual riders had 4.1 Auto rear ends diff to replace their 2.87 Manual rear ends, they would get 43% more precious revs in 6th.
That puts the redline at over 200 kph, so still plenty of headroom on our highways and scope for extra 人馬一体 goodness to suit our Downunder Speed Limits !

[hks_kansei]

Wait, so the ND doesnt have an overdrive gear?

I'm actually quite shocked at that, since pretty much every car since the 3 speed days has had at least one overdrive gear.

1:1 in 6th is genuinely strange.

[Mr Morlock]

The 6 speed is not an overdrive top and I wonder if that is really a good move. An NBP2 works well with the 6th o/drive. Not sure how that works for an auto but one thing that is already becoming evident is that autos are making real headway as the transmission of choice. I have dríven a few NCs with auto and one in particular drove very well and a day or two in one would give an idea of what its like in the country and on twisty roads. Clearly it would be a winner in traffic the bane of big cities before 9.30 and after 3.30 or so. The jokes about autos are heading towards lame- auto developments are moving on.
The argument about ratios being wrong is questionable i.e. presumably they are chosen to suit the country or region that the vehicle is being sold.

[JBT]

How some view an auto tranny.

Auto Trans.jpg

[hks_kansei]

The 6 speed is not an overdrive top and I wonder if that is really a good move. An NBP2 works well with the 6th o/drive.

The argument about ratios being wrong is questionable i.e. presumably they are chosen to suit the country or region that the vehicle is being sold.

I'm not suggesting they're wrong, they just seem to be an odd choice compared to what I have seen from many other cars.

Although, seeing that it has an unusually tall final drive would make up for the short gearbox ratios however (and would bring cruising RPM down)

I can't be bothered to do the sums right now, but at a guess 6th may end up at the same RPM as if the car had more conventional gear and diff ratios.

[tennyson]

I had two NC's both with auto and now my new ND, with Auto.

I have had a lot of cars, a lot of them were manuals and an equal number were auto's.

My first NC had a great gearbox, however on the track it was a bit of a let down. It would not hold in gear and I think if I was going to go tracking more, I'd give the manual a thought.

My second NC, which was a second generation, was a completely different animal. It would hold in gears, had the flappy paddles on the column and was a real dream to drive.

When I ordered my ND, in May of this year, I thought about buying the manual, but when I found out they were using that same gearbox from the NC, I changed my mind.

Am I happy with my decision...hell yeah!

We took Ruby on her first official car run last weekend up to Mount Tamborine and going up and down the mountain in Manual was a real hoot. I knew about the blipping in the upshift, but found out that it also does it on the downshift.

My wife was so amused, she said she has never seen me so animated about any other car...more importantly, Gearbox!

It is the NC box, but at a higher level, with more smile factor!

Auto, manual, I don't think they are universal, we all like different things. Isn't it nice that Mazda see fit to give us a choice?


Frank

[greenMachine]

It's there so people with disabilities and elderly people who struggle operating a clutch due to aging are not alienated from the market.
It isnt ideal but at least these people have an option to own and drive the car in automatic form. Also boosts sales with lazy people who just want to cruise in something pretty.

Bloke I bought GM2 from, he has a developing problem which means he will be restricted to autos. I don't think the bag of gold I am about to leave with him will get him into an ND though, I don't even know if he has thought about an auto MX.

[pcmx5]

The 6 speed is not an overdrive top and I wonder if that is really a good move. An NBP2 works well with the 6th o/drive. Not sure how that works for an auto but one thing that is already becoming evident is that autos are making real headway as the transmission of choice. I have dríven a few NCs with auto and one in particular drove very well and a day or two in one would give an idea of what its like in the country and on twisty roads. Clearly it would be a winner in traffic the bane of big cities before 9.30 and after 3.30 or so. The jokes about autos are heading towards lame- auto developments are moving on.
The argument about ratios being wrong is questionable i.e. presumably they are chosen to suit the country or region that the vehicle is being sold.

Not sure about the market argument, yanks have higher speed limits and their NC's got a 4.1 diff and we get a 3.7??? Where is the logic in that?If you have dríven an NC with a 4.1 you would understand what a difference it makes to performance with very little difference in economy if dríven in the same manner.

The ND 1.5 has moonshot gearing and it has nothing to do with 6th being 1:1 but the 2.866 diff ratio in the manual,after all it is the combination of the two that determines overall performance. Auto has 0.582 6th but a 4.1 diff. Guess what enthusiast are going to do when they find the first wrecked ND auto!!!
Use their own LSD and the 4.1 ratio.(auto's are non LSD).
I have dríven an NC auto and really liked it so certainly recognise the need and indeed desirabilty of having a good auto for those who want it.good on them I say!

Peter.

[97 MXV]

Using a non overdrive transmission is a curious bit of engineering. The idea of an overdrive is to speed up the output shaft of a transmission relative to the input shaft. This allows higher road speeds with the same size gears in the other 5 ratios.
Now making 6th gear non overdrive means the diff ratio must be higher for the same overall ratio in 6th meaning the other 5 transmission ratios are therefore lower.

This all means that more of a low speed/high torque design is required for the transmission and propshaft. This does not make a lot of sense as rotating component durability is reduced exponentially more by increased load than by increased revs.
That means the transmission and driveshaft are heavier than they need to be, dríven by higher maximum and mean output shaft loadings.
The engine and diff mounts need to be heavier also. (Axle torque change is not a factor being dependent on overall ratio only, which would not necessarily change.)
Seems strange to go from a high speed/low torque drivetrain to a low speed/high torque drivetrain, when we know weight saving is a key design goal

And this is strange too.....the 1.5 ND is way over geared for an enthusiasts car with a 7500 rpm redline and subject to our speed limits or even compared with the 2.0 ND.
Already some foresee lower diff ratios bringing the same smile to 1.5 ND owners that a 4.3 diff does to NB8B owners suffering the standard 3.6 ratio.

The ND 1.5 has moonshot gearing and it has nothing to do with 6th being 1:1 but the 2.866 diff ratio in the manual,after all it is the combination of the two that determines overall performance. Auto has 0.582 6th but a 4.1 diff. Guess what enthusiast are going to do when they find the first wrecked ND auto!!!
Use their own LSD and the 4.1 ratio.(auto's are non LSD).Peter.

Now if Manual riders had 4.1 Auto rear ends diff to replace their 2.87 Manual rear ends, they would get 43% more precious revs in 6th.
That puts the redline at over 200 kph, so still plenty of headroom on our highways and scope for extra 人馬一体 goodness to suit our Downunder Speed Limits !

[StanTheMan]

I was under the impression auto gearbox changes are way faster than manual these days.
I drove a 911 recently the speed of the Auto was insane. It changed in the middle of a corner too, which in driving a manual spirited....would be sinfull.
it was so quick you hardly even noticed it.

Sure he ND isn't a Porsche. But the Porshe itself wasn't so mind blowing to drive.

[hks_kansei]

I was under the impression auto gearbox changes are way faster than manual these days.
I drove a 911 recently the speed of the Auto was insane. It changed in the middle of a corner too, which in driving a manual spirited....would be sinfull.
it was so quick you hardly even noticed it.

Sure he ND isn't a Porsche. But the Porshe itself wasn't so mind blowing to drive.

Depends on the box, if it's the normal torque converter style, or the more modern twin clutch thing.

Pretty sure the Porsche ones are the twin clutch thing, which are closer to being an electronically operated manual than to a regular auto.

The twin clutch ones are quick because they have the ability to have the next gear selected ahead of time and just need to let one clutch go and grab the other.
Vs a regular manual where the clutch goes in, the gears then move to select the next one, and the clutch then grabs again.


And a regular auto is different again, where instead of a clutch is has a viscous coupling (Torque converter) that intentionally allows slip so that the gearchanges are smoother.



edit:
Pretty sure the ND has a regular auto.
If it had a twin clutch thingy i'd expect Mazda to have made a huge song and dance about it.

[Mr Morlock]

apart from technical details of whats good and whats not just driving modern autos gives a good idea for how quickly and how seamlessly they can perform. DSG's often get criticised.

[davekmoore]

It's not a twin clutch thingy (DSG).

Nor is it a Skyactiv unit.

Works well though.

Just wish it came with LSD (the diff type, not the drug).