The 9 Speed transmission

[95nsxtc]

i currently have a 2015 tlx on loaner from the dealer and it has a 9 speed. its quite nice allowing redline in any gear and fairly responsive

i was wondering if anyone had an idea of how similar this could be to the NSX's or if this one is a derivative of it

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also something to discuss:

do you think that the ninth gear will be better for long term life for keeping the engine at a very low non stressing rpm or make it more prone to carbon build up?

 

[Adamantium]

9 speed doesn't mean low engine revs so much as it allows the engine to remain closer to peak torque for more time.

if you have an engine with a peaky torque curve more gears result in a faster car so long as you have lossless changes which you pretty much do.

i believe the 9 speed on the tlx is not a twin clutch so I doubt there are any similarities. My concern is within the available space, each of the 9 years will be narrower resulting in low tolerance to increased power. At least the gearbox only drives one axle.

 

[95nsxtc]

9 speed doesn't mean low engine revs so much as it allows the engine to remain closer to peak torque for more time.

if you have an engine with a peaky torque curve more gears result in a faster car so long as you have lossless changes which you pretty much do.

i believe the 9 speed on the tlx is not a twin clutch so I doubt there are any similarities. My concern is within the available space, each of the 9 years will be narrower resulting in low tolerance to increased power. At least the gearbox only drives one axle.

right, more gears = more available power band, but obviously will result in lower rpm at highway cruising vs ours being between 3-3.5k, which is what led my curiosity to how long intervals will effect the engine. if i cant use this new nsx over long distances then im jus getting a 570s or 911 turbo s. and i hadnt thot of ur concern but that makes sense too

but yea the 9 speed in the tlx is a zf and the 8 speed is a dct

 

[Adamantium]

Doesn't have to mean lower cruising revs. Typically more gears spread over the same range and top gear overdrive is fairly common. More dictated by Rev limit than number of gears.

I'm pretty sure it will be great over distances though and much as the 570 and 911 are lovely cars, for me they are just totally outdated by the new tech in the NSX.

Until tesla bring out a proper modern sports car of their own design, everything bar the 918 (and even that really) is lagging behind the NSX.

do want to see what the R36 GT-R is going to be like but it's a good few years off.

 

[95nsxtc]

Doesn't have to mean lower cruising revs. Typically more gears spread over the same range and top gear overdrive is fairly common. More dictated by Rev limit than number of gears.

I'm pretty sure it will be great over distances though and much as the 570 and 911 are lovely cars, for me they are just totally outdated by the new tech in the NSX.

Until tesla bring out a proper modern sports car of their own design, everything bar the 918 (and even that really) is lagging behind the NSX.

do want to see what the R36 GT-R is going to be like but it's a good few years off.

i very much agree with everything you jus said and i do hope it lives up to our expectations

the new gtr will b interesting, i dont kno much on it besides the continued mentioning of that 3.0 derivative of their GT-R LM

 

[Acura NsX Pilot]

I drove the new TLX and it was amazing especially in the sport mode.

 

[Superfluous]

I hope the NSX transmission rolls over to the next gear when you hit the rev limiter. Some dual clutch transmissions bounce off the rev limiter, but stay in the same gear. Others -- e.g., the 911 TT and GTR -- roll into the next gear without skipping a beat.

 

[BATMANs]

Not sure if anyone knows this but the C7Z06 automatic tranny shifts faster than the PDK from Porsche.

 

[Adamantium]

Isn't it common for top end autos to outshift the dct? I thought the downside of the auto was the power wasted whilst operating through the torque converter.

 

[95nsxtc]

Not sure if anyone knows this but the C7Z06 automatic tranny shifts faster than the PDK from Porsche.

u sure about that? just like u sure the z06 does 0-60 in less than 3 seconds?... not really going to argue about the up shifts bc value in any dct/auto is not in the upshifts, its the response from the downshift, which is garbage on the z06

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I hope the NSX transmission rolls over to the next gear when you hit the rev limiter. Some dual clutch transmissions bounce off the rev limiter, but stay in the same gear. Others -- e.g., the 911 TT and GTR -- roll into the next gear without skipping a beat.

this is a battle i face all the time on which one i like bc both have their perks from rolling into next gear or having to shift urself

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I drove the new TLX and it was amazing especially in the sport mode.

it is quite a good car for the money, i am really impressed myself with this, kinda sad to turn it back in

 

[Elistan]

I have two vehicles that, while they are both RWD, 2.0L four-cylinders, and both are fun to drive, are otherwise exceedingly different in terms of drivetrain. They are an S2000 (naturally aspirated 9000 rpm, 6 speed manual) and BMW F30 328i (turbo ~6500 rpm, 8 speed auto by ZF.) The auto is a planetary gearbox with a torque converter. The TC locks very, very early - it's basically just to get the car going. Once moving the car feels like it has a direct clutch connection between the engine and the wheels. The auto also can shift extremely quickly - as quick as a PDK, even quicker than an Audi S4's DCT. (Which really surprised me, but it was a friend's car and I don't know what mode it was in. Possible the S4 can shift more quickly.) This depends on the mode the BMW is in and how I'm driving, of course - when driving sedately in the default mode, the shifts are smooth and almost imperceptible. When it shifts quickly there's a nice kick to it.

I like the S2000's transmission when driving around town or in the mountains. It's direct and immediate. It can be fun at autocrosses and track days, but heel-toe downshifts don't always go perfectly. It sucks in stop-and-go traffic.

I like the BMW's transmission in traffic (it's effortless in auto mode) and driving spiritedly (it's responsive in manual mode, let's me concentrate on the steering and throttle more, and except for downshifting to prevent stalling it does exactly what you tell it to do - it'll even bounce the engine off redline if you configure it for such.) Driving around town in manual mode just doesn't work - the engine is way too quiet to give feedback on shift points. When I try it I often look at the tach only to realize I'm cruising along just below redline. This is quite different from the S2000, which of course gives constant and very noticeable feedback on engine speed. (Which I love. I wish with BMW engine was much louder in the cabin.) Also with eight closely spaced gears that's a lot of fiddling with the paddles to keep the engine at the rpm I want. Finally, while I don't have direct personal experience with it, I think the 8 speed auto BMWs get gas mileage as good as or better than the 6 speed manual ones.

I have no experience with Acura's current transmissions, and it sounds like the NSX's will be different yet again. But assuming there's a proper level of feedback from the NSX engine on where it is in the rev range, I think it'd be quite happy having one with a 9 speed DCT. It won't be as engaging as a manual on city streets (not like all that HP can be used properly there anyway) but when autocrossing and tracking it should perform superbly, and with just normal driving it should deliver very good efficiency and convenience.

 

[BATMANs]

u sure about that? just like u sure the z06 does 0-60 in less than 3 seconds?... not really going to argue about the up shifts bc value in any dct/auto is not in the upshifts, its the response from the downshift, which is garbage on the z06....

what exactly is garbage about the downshifts of the new Z06?

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=z06 2.8 seconds

http://www.motorauthority.com/news/...-z06-shifts-faster-than-porsche-pdk-heres-how

http://www.hotrod.com/news/2015-corvette-z06-clocks-0-60-in-less-than-3-seconds/

http://www.usatoday.com/story/money/cars/2014/08/20/2015-corvette-8-speed-transmission/14352021/

 

[95nsxtc]

what exactly is garbage about the downshifts of the new Z06?

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=z06 2.8 seconds

http://www.motorauthority.com/news/...-z06-shifts-faster-than-porsche-pdk-heres-how

http://www.hotrod.com/news/2015-corvette-z06-clocks-0-60-in-less-than-3-seconds/

http://www.usatoday.com/story/money/cars/2014/08/20/2015-corvette-8-speed-transmission/14352021/

first off im gona point out something, those are all american sources, theyre always gona b biased to american vehicles and if u dont believe that ur on some good drugs. i purposely wont read american based magazines on anything automotive for this reason

second, they say in those articles that the claims were also made by gm officials, who arent exactly known for honesty and for some reason that people in the real world cross shop 911s and corvettes, and if u believe their honest that ur on some very very good drugs

third, ive driven the z06 c7 8speed (the 7 manual is retarded, drove it in z51 form), it is a mad machine but the downshifts are hesitant under slight and heavy decelerration at this level of vehicle. the equivalent porsches ive driven downshifts are quicker and crisper

 

[95nsxtc]

o and the driving was done at vir and surrounding roads if u were wondering

 

[nikey22]

Here are the suppliers of Dual-Clutch Transmissions:

BorgWarner
EATON
Fiat Powertrain Technologies
FEV GmbH
Getrag
Graziano
LuK
Ricardo
ZF Friedrichshafen AG

Which one will be in the NSX? - my guess is the ZF, since that's the one used for the TLX.

 

[areout]

Isn't it common for top end autos to outshift the dct? I thought the downside of the auto was the power wasted whilst operating through the torque converter.

nothing can shift faster than doubleclutch transmission except CVT which again doesn't shift in a classic way

 

[Adamantium]

Don't think that's true. It will vary from dct to dct. The grazzioni single clutch in the aventador is faster than all the Audi s-Tronic and vw dsg boxes I can think of.

 

[JD Cross]

Don't think that's true. It will vary from dct to dct. The grazzioni single clutch in the aventador is faster than all the Audi s-Tronic and vw dsg boxes I can think of.

I need to learn something here.

Wouldn't a dual clutch engage/disengage be faster than a single clutch?
As one dual clutch is disengaging the other clutch can begin to engage.
The gears in the DCT have already been selected so no time loss there.

The single clutch presumably has to disengage before a gear change can be started.
The gear change itself will take some amount of time before the the single clutch can begin it's reengagement stroke.

There's some physics here I don't understand that I'd appreciate you explaining.

 

[jwmelvin]

There's an assumption or two in there. While a DCT can predict the next gear, that's not guaranteed. And the transition time just depends on how the transmission is programmed and how fast it's actuators are. A single clutch is kind of the same in that regard. I agree that when optimized, a DCT should be faster, all other things equal. But some DCTs just aren't all that fast. The Alfa 4C is an example (still way faster than a stick). And some automated single clutches are not fast (e.g., BMW E46). I suspect the NSX will be rather fast.

 

[95nsxtc]

I need to learn something here.

Wouldn't a dual clutch engage/disengage be faster than a single clutch?
As one dual clutch is disengaging the other clutch can begin to engage.
The gears in the DCT have already been selected so no time loss there.

The single clutch presumably has to disengage before a gear change can be started.
The gear change itself will take some amount of time before the the single clutch can begin it's reengagement stroke.

There's some physics here I don't understand that I'd appreciate you explaining.

jwmelvin is definitely right. but the difference too is that a dual clutch isnt as harsh on the clutch as the single automated is. for example the aventador is a single clutch and it does shift at <50ms. but i can tell u from all my friends that this wears the clutch out fast af. 3 out of the 5 have had to get new clutches sub 15k mi

 

[jwmelvin]

a dual clutch isnt as harsh on the clutch as the single automated is

Good point.

 

[Adamantium]

Totally agree with the above.

The aventador actually isn't a nice experience and I bet it does wear damn fast. It's faster because of the physical speed of gear shifting rather than the clutch itself.

Not smooth at all.

F1 cars shift much faster still but are sequential boxes not requiring clutched shifts at all.

JD Cross, there's an overlap between disengagement of one and re engagement of the next of the other which produces a triangle. The skill of programming is to start and complete the torque transfer path change while completely underneath the clutch cross over graph.

It becomes a compromise between speed and smoothness. By mechanically improving the clutch and gear components you can reduce the time required to shift gears and therefore reduce the clutch overlap envelope and so speed up the clutch without compromising smoothness. The Porsche pdk is about the best at the mo in this regard.

the aventador goes faster by not prioritising smoothness.

 

[areout]

Don't think that's true. It will vary from dct to dct. The grazzioni single clutch in the aventador is faster than all the Audi s-Tronic and vw dsg boxes I can think of.

aventador shifts in <50 ms while DSG needs from 6-20 ms or so they say

https://www.youtube.com/watch?v=PH00yBaAV7s

 

[Adamantium]

I haven't checked the links you posted but I know that you need to be careful of what the numbers quoted refer to. Some refer to cog swapping time some refer to total torque interruption to re-engagement time.

 

[95nsxtc]

aventador shifts in <50 ms while DSG needs from 6-20 ms or so they say

https://www.youtube.com/watch?v=PH00yBaAV7s

i jus did the 2 min google lookup research on this and it appears that there is some confirmation/agreement in this time slot (i still dont believe it at all) and some arguing at the same time, and apparently the later posts all say that this was a misprint by VW and they later fixed it to say the correct time which is ~200 ms.

but back to a point of the corvette z06 talk real quick and what i just learned, these guys all agree that downshifts are WAY slower at 600~900ms

also heres a nifty picture i found from 08 from lexus