John T

Great point Joe....back in the day everybody wanted the Dodge Caravan with the Mitsubishi motor and same with a particular Saturn that had a Honda V6 option.

I will order my C7 with that 8 speed. I just don't want a manual this time around.

Nuieve

GM trannies always sucked. Just look what CTS-V has.

Asian trannies are usually at least good.

GM wants to build their own not because it's better, but because it's cheaper to build it in-house.

Unless GM's version is some kind of dual clutch, I'd rather have a Japanese tranny.

Of course, final opinion to be made when some review pour in...

JoesC5

Looking at the torque specs on the Lexus V8 with the Aisin 8 speed, I doubt that a high performance version(LT4???????) engine will be available with the "first year" auto transmission. The Aisin might be able to handle 450 lbs-ft but I doubt is good for 500+ lbs-ft. It's possible that the GM auto 8 speed will be a heavier duty version that can handle the higher torque output of a LT4??????(like the 6L90 now used in the CTS-V), unlike the 6L80 used in the base/GS C6. As we know, GM never tooled the 6L90 to be used as a transaxle in the C6, which meant that the Z06, 427 Convertible and the ZR1 never was available with an auto transmission.

Who knows what lurks in the darker areas of GM's mind?

Nitrous Oxide

The DCT on the Bugatti is from Ricardo.

NSC5

According to the fairly limited information Aisin makes available the TR-80SD (8 speed, high torque, RWD application) is rated for 800 Nm torque (roughly 590 foot pounds). It doesn't specify what, if any, limitations are imposed (lower torque limits for certain gear ranges, power reduction during shifts, etc.) I assume the TR-80SD is what would be repackaged for the C7 if the Aisin reports prove true.

Hopefully GM will have a good plan in place to handle warranty issues. A friend who used her Dodge diesel pickup to haul horses went through some issues with the Aisin 6 speed auto. The problem was pretty minor but it was magnified by lack of parts availability and expertise within the dealer network. She ended up dumping the pickup after 15 months because of these issues. A lot depends upon how many models would use the same/similar transmission and whether this is truely a one year relationship.

Kappa

The CTS-V trans is pretty good in the ones I've driven. The current year trans got some updates from the ZL1 program that made the manual shifts very quick.

glass slipper

I agree that the Aisin doesn't have the torque capacity to stand up behind the LT1. But to address the bolded, there is nothing special about the 6L90 that prevents it from bolting up to the torque tube or differential so it wasn't a matter of "tooling". The problem is the 6L90 is 35mm longer than the 6L80 and the floorpan of the C6 simply won't accomodate it. If a 6L80 and a 6L90 were sitting 5 feet from each other, the casual observer wouldn't be able to tell the difference between them, especially looking at the front and rear...those places are identical.
Also, the 6L80 in the C6 isn't a transaxle but we've had that discussion before...a transaxle contains the differential and transmission in the same case. But if you want to call it a transaxle, go ahead.

glass slipper

You are pretty clueless. GM automatic transmissions have always been great. Rolls Royce has used GM automatics in the past and they use nothing but the best. The 6L90 in the CTS-V is probably the strongest 6-speed auto in the world...how many others can handle the torque of the ZL1 580 HP engine.

Carver Electrics

....

S'vette

I think Ricardo as does Audi uses the DCT part only in their whole setup and then call it quattro or something else they can call thier own. But the actuall DCT is from Borgwarner and they say is about as big as a dinner plate. I saw this awhile back and this thread reminded me of it. It may have been used in some older bugatti models, Im not real sure on that one but they are going to be suppling for alot of car companies now.

"BorgWarner leads the globalization of dual-clutch transmission technology with awarded business in Europe, North America and Asia. Customers include VW, Audi, Bugatti, SAIC, Nissan and Getrag dual-clutch transmission programs with five additional global automakers. At full-launch of announced programs, the company will be providing its innovative DualTronic(R) technology to an expected 2.3 million dual-clutch transmissions per year. The company launched the first commercial production of dual-clutch transmission technology in Europe in 2003 with VW/Audi. Today, BorgWarner is working on over 20 programs with transmission and vehicle makers around the world.
PR Newswire (http://s.tt/1rKaG)"


I wonder how their stock is doing?

jvp

Regarding his second and third points:

2. If I recall correctly, when the CUE system was first introduced a year or two ago, the marketeers at Cadillac were asked about it trickling down into GM's "lower" marques. They were pretty emphatic it would stay a Cadillac-only system and not find its way down-scale (like or not: Corvette is a Chevrolet and considered down-scale from the Caddies).

My guess is that we won't see anything CUE-related on the C7.

3. Regarding the love of DCTs: as has been posted by a couple of other good observers, there are few reliable DCTs able to cope with high levels of input torque while remaining affordable. This DQ's things like the beast in the Veyron, as I believe it costs more than a Corvette does.

What if GM can design an auto that can shift as quickly as a DCT and allow full manual control? Is a DCT necessary?

Just some stuff to think about.

jas

JoesC5

The 6L90 is designed to bolt directly to the engine and uses a conventional propshaft. When I said that GM has not tooled the 6L90 for the transaxle application, I meant just that. GM does call the transmission/differential in the C5/C6 a transaxle, so that's what I call it. To use the 6L90 transmiison in a C6, it must be tooled up(new housing, tailshaft, etc). A 6L90 can not just be "bolted up", as you claim, to the torque tube and differential. In addition, the extra length of the transmission, would mean a new torque tube/prop shaft would have to be "tooled up" because of the longer 6L90 transmission hosuing.

Of course, the larger size of the 6L90 has to fit in the allotted space, but it has to be tooled up(redesigned to fit the application).

I bet most people could tell the difference between the 6L90 and the 6l80 transaxle from 5 feet.

jvp

FWIW, GM can call it whatever they like... but it's NOT a transaxle. Period.

jas

Nitrous Oxide

Ricardo is a British company. They seem to work on very specialized programs:

"Access to extensive development testing facilities and the Ricardo high performance transmission product manufacturing organization to provide high quality development parts in extremely competitive timescales (currently supplies components to F1 teams as well as the award winning Ricardo DCT for the Bugatti Veyron)."

http://www.ricardo.com/en-GB/Our-Mar...Transmissions/

I think your Newswire quote is either wrong or they're not talking about the Veyron.

http://en.wikipedia.org/wiki/Dual-clutch_transmission

JoesC5

Show me one definition of a transaxle where it states that the transmission and the differential have to share the same one piece housing and the same fluid.

Here is one difinition of a transaxle...


"In the automotive field, a transaxle is a major mechanical component that combines the functionality of the transmission, the differential, and associated components of the driven axle into one integrated assembly." http://en.wikipedia.org/wiki/Transaxle

Another definition of a transaxle...

"trans·ax·le
   [trans-ak-suhl, tranz-] Show IPA

noun
a unit combining the transmission and differential of a motor vehicle and connected directly to the axles of the driving wheels."

http://dictionary.reference.com/browse/Transaxle

jvp

I think you sorta did that yourself...

The diff and transmission on a C5 and C6 Corvette (and very likely what'll be on the C7) are 2 independent units that are butted up against one another, and therefore attached. They're not A mechanical COMPONENT. They're 2 components.

jas

JoesC5

Definition of Integrated...."combining or coordinating separate elements so as to provide a harmonious, interrelated whole:"

Do you not agree that the Corvette engine also meets the definition of intergrated. It is made of of various seperate elements(block, heads, intake manifold, oil pan, etc) that when combined become an intergrated unit, just as the Corvette's transaxle is.

The transmission and diffential in the C6 is more then two components "butted" together. The output shaft from the transmission is also the input shaft to the differential's pinion gear. In the case of the Corvette's transaxle, it is nessary to have two different fluids, thus is easier to have two cases bolted together to form one intergrated unit, to seperate the two required fluids. This was true back to the 1960 Corvair which also has a transaxle and the powerglide transmission required ATF fluid and the differental required gear lube. Many transaxles have been built using a single casing but they were able to use the same fluid for both the transmission and the differential, but that dosen't mean that transaxles that have two seperate casings bolted togther are not transaxles.

In the very early days of engine design, they didn't have a way of sealing a seperate block from a seperate head, thus early engines had the block and head cast as one unit. Later on, when the head gasket was developed, the head became seperate from the block. That didn't mean that the later design engine with seperate componets were not an engine. The seperate block and seperate head were intergrated(bolted) to become an engine(along with other seperate components intergrated into the "engine".

Bill Dearborn

1. We really haven't seen the car yet so we don't know if it will look good or not. A little early to tell.
2. So what if it doesn't use the Cue system??? No matter which manufacturer most of those systems are over valued. Once I get things set I don't play with the crap anyways except to tune the radio once and a while. Best way to allow that to happen is to have some ***** and all manufacturers are going away from those to less workable solutions because a fancy screen impresses people who think they can play games driving down the road Vs looking where they are going.
3. I really haven't seen any comment that a DCT won't be offered. Remember a 7 speed manual could be a DCT since a DCT is just a manual transmission with a different shifter controlling it.
4. So the GM 8 speed isn't ready? The issue with having a different manufacturer for one year isn't something that will affect owners until about 15 years down the line. That is when parts might get hard to find. If it is shared with other OEMs then that might not happen. However, GM will see some increased cost due to the logistical cost of maintaining two different assemblies. Even if they only use it for one year the extra parts cost the manufacturer money down the road. Reducing part numbers required to build a product is always going to reduce development, record keeping, production and service/support costs.

Bill

Mike Mercury

the definition of a transaxle is simply:

"The transmittion and the driven axle are not coupled by a driveshaft"

and anyone that no longer lives with their parents - knows this.

BlueOx

I had one of those and it went through TWO trannies in 5 years. Whatta piece of CRAP!