NSC5

And I have to admit a large part of my choice of transmission indecision stems from my involvement in enterprise risk management over the past 20 years. There is that nagging thought that no longer being sharp with a manual could result in a slight reaction delay that makes the difference between avoiding an accident and becoming part of one.

On the other hand I keep in mind that several years ago I took my then 3 year old daughter camping in the Colorado Rockies for the first time. This was a father/daughter solo trip and as I was setting up the tent I was running through all the possible disaster scenarios (everything from severe weather to a stampeding herd of elk). I was seriously considering switching to a hotel in Estes Park after finishing setup but then I went over to Anna who had been sitting at the picnic table watching setup and she was excited to show me the "wooden marbles" she had found. I gently explained those were animal droppings and this, the biggest disaster of the trip, was quickly rectified though through the use of an anti-bacterial wipe

Transmission choice may end up being a coin flip and maybe I will get a friend to flip the coin so I can blame him later!

SCM_Crash

OK, that's fine and dandy, but - so we're on the same page here - a Ferrari 458 is $230,000 while a Corvette is (at most) half the cost and (at base) 1/4 the cost. Do you feel that a DCT, being far more expensive as you increase power output, is a viable solution in a Corvette?

I know a lot of people are crapping Cadbury eggs to get a DCT in the Corvette because it's in there Golf GTI or whatever, but there's a big difference between a DCT handling 180HP and a DCT handing near 500.

Now, I'll admit there's a level of control in a DCT you can't get from a conventional auto, but I beg to differ about feel and especially beg to differ about control when comparing to torque converter autos as a blanket statement.

You have to remember that high performance autos are NOT conventional single-planetary gear train autos. Just like a DCT, the performance autos ready gears for up shifts. The difference is that the auto uses clutch packs on separate gear trains while the DCT uses separate clutches on a single gear train.

But one thing I can tell you is that the lower-cost DCTs I've been in are not that great in "feel" at low speed. A major benefit to the torque converter is that - unless the computer doesn't unlock the converter - the engine doesn't stutter or stall. With a DCT, the computer has to decide if it's going to slip the clutch, burn it, let the engine chatter, or whatever when you're driving at low speed. And low speed driving DOES happen a lot here in Los Angeles. Not to mention that DCTs allow the car the roll back on a hill. With a manual, that's on YOU. My car doesn't roll back when I'm driving on a hill. But if I didn't have control over the car with a DCT because IT controls the clutch, my car could roll back if I don't give it enough gas and possibly hit the car in front of me. (Just a thought) In this case, you definitely don't have the control you do with a standard manual. (I know that's not what this discussion is about.)

Be that the case, I've yet to hear or see any solid evidence that puts in question GM's decision on what auto should go in the Corvette.

So, what exactly makes it "far" superior. You're not stating anything here other than your opinion based on cars you've ridden in. I've ridden in PDK and DCT cars too. Doesn't mean anything to me.

I want to know what makes them "far" superior. At this point, you've told me that the down shift is the difference. So, please enlighten me and tell me what makes the down-shift on a DCT so much better. I'd like to know because, again, I keep hearing this purple unicorn craze about DCTs without anyone backing it up with real information other than, "It's what's in <insert a German/Italian car here>".

LS1LT1

Well, at MSRP maybe, but good luck trying to pay only $230k (or even only $275k) for a new 458 right now LOL.

SCM_Crash

LOL! Good point. I'm sure Ferrari's DCT is at least $15K before the crazy mark up. I wouldn't pay an extra $15K for a Corvette just because it has a DCT. That just dumb. And I'm very sure that the majority of Corvette owners wouldn't either. I'm sure there'd be a few here and there, but not even remotely enough for GM to say, "That's a good idea."

johnglenntwo

It hasn't hurt Porsche, since, I heard they are the most profitable car company in the World!

cmicasa

Special note to GM from ^^^ This Guy:

Hey GM because Porsche does it.. please charge us an additional $15K for a pointless addition that most will use about as much as Porsche drivers (read "once in a blue moon if ever) just for the sake of saying I have it. Like Porsche owners.. I like giving U my money for performance that 95% can keep up with that of a $50K Chevy, let alone the $70- $130K ones.

Raitzi

DCT should be a performance option and they could charge as less as they want if GM is not interested to make money.

johnglenntwo

Don't you want to see the Vette get faster then the ZR1!? DCT is essentially "Out of the Box", and a straight forward way to move forward.

If you have something better please share!

SCM_Crash

I don't see how it's any faster, to be honest. I know it shifts faster. But it doesn't make the car faster. LOL If it does, it's such a miniscule increase in speed, it's not worth the $10-15K extra cost.

Raitzi

If faster just means top speed for you PDK improves Porsche Carrera S 1/4 mile time by 0.5-0.7s. And 10k is too much. VW charges about 2k so manufacturing cost for high performance unit could be around 4k.

cmicasa

Faster than the ZR1??? Damn.. tranny is not gonna really help that much. Maybe 2/10ths.. but for $10-15K??? Sorry... Just don;t see it as worth it. If GM puts one in for $2k more.. sure.. OK.. $1K per tenth.

The ZR1 is hands down one of the fastest cars on the planet.. it's limitations come from being not AWD or having a 40 front/60 rear weight distribution going on. AWD would turn a 3000lb Corvette into a 3500lb mess in my opinion.. all for the sake of a measurement that is pointless on a road course (0-60) with a car with 400HP+ (640HP in the ZR1's case)

2K3Z06

DCT will be worth about a .5 to a full second over a manual transmission on a road course per lap. Times that by 20 laps and its easy to see that it is superior, just by using lap times as a performance criteria.

1/4 mile times are also improved, especially on a turbo car. because their is no throttle lift when shifting. so no temporary loss of rpm, and on a turbo car their is no loss of boost pressure, so the enigne stays at full power.

Plus. have you ever been on a road course? Try shifting while in corner, it will upset the chasis and cause a loss of control (spin). A DCT can do it, using a soft relase of the clutch, combined with electronics of the chasis. (eshocks, traction control)

Also, have you ever tried to shift a manual box while on a bumpy road course? usually you will bang a gate, or hit neutral. A DCT will pre select the next gear since it has 2 clutchs, for a nice positive shift even on a bumpy track. Plus when your done at the track, put it in auto mode for a nice slow ride home.

A DCT does not cost more to manufacture than an automatic transmission, you still need a case, gears, drive shafts, same as auto trans. The higher cost comes the engineering development, not the manufacturing process. And lets face it, Audi did all the heavy lifting when it comes to DCT transmissions, All GM has to do, is buy their DCT box and take it apart, and then try to improve it. At least I think it is Audi that holds the patent for the DCT transmission. Porsche???

As bill said, autos just dont work on a road course. downshifts suck, delayed action, and there is a big heat problem to deal with.

DCT are not a new technology, they have been around for over 10 years. I drove an SMG BMW M3 way back in 2003. I will say it wasn't very good at low speeds (parking lot). The new DCT's are frigging awesome, if someone says different. They obviously have not tried them, and really can't objectively say they are not any good.

Look at the Lexus LFA and new La Ferrari, the engines build RPM so fast, I really don't think a human could shift a 7 speed manual box fast enough to keep up. The vette does not twist up that fast, thats why it can get away with a old timey gear box.

Another benefit is that you can focus on your line and braking points, and other cars when your really hauling ***. Which leads to improved lap times.

Don't just take from some smucks on the net, go drive (rent) a Ferrari or Porsche with a DCT box. You will be amazed. Be warned, you won't want to go back to a clunkly old manual.


Hope that ansewers some questions, Cheers

lt4obsesses

This is exactly why the DCT will not be in the Corvette. When a DCT will fit the the design parameters, and the benefit will rationalize the cost factor, it will be in the Corvette. But not until then.

johnglenntwo

B747VET

To my knowledge, a new Ferrari transaxle can cost well over $22,000. $30,000? A used F40 transaxle can run $18,000.

The previous Ferrari F1 DCTs were not great trannys, were very problematic and are horrendously expensive to repair. Think $6,000 to $8,000 for a fairly simple rebuild. Think $12k+ for a complex rebuild.

1% of Corvette owners have the slightest need for a high quality super fast shifting DCT.

Yet, some folks on here live in some fantasy land where they think that the additional developmental costs and production costs of perhaps $20,000+ per car will willingly be borne by the Corvette masses that are historically looking to pay $54,000 for the whole car just so that you of the 1% group can have a racing quality DCT? Really?

The non-DCT DB9 tranny shifts more than impressively and is in a price range that we might possibly see in a higher end Corvette in less than two years. It lets you go very deep into any corner and keep the car balanced while madly downshifting 3 times without all the irrational costs of a Ferrari high performance level DCT.

All of these similarly crazy fantasies where a 3,100 pound C7 with 650+ HP and a Ferrari caliber DCT is going to cost less than $100k, let alone $150k to $200k, are fascinating to listen to but will remain frighteningly unrealistic.

A "DCT" in a 200 HP low torque VW GTI doing 0-60 in 7 or 8 seconds is worlds apart from a true competition quality 8 speed DCT in a C7 that can handle 600-700 HP and maybe a 650 torque range. And no, they aren't going to build a 450 HP/450 Tqe capable 8 speed AND a 700 HP/650 Tqe capable 8 speed. They will only build one and it will never be in the Ferrari league and might never be a DCT. Get over it folks.

The PDK caliber of DCT is a very unique co-development between ZF & Porsche and is at least three to four years ahead of GM and has inherent design cost efficiencies that GM would find almost impossible to meet. Maybe someday, but not now. Also, torque ranges in Porsches are well below what the C7s will likely ultimately generate.

Keep in mind that you can't buy a manual tranny in a new high end Ferrari. There is inherent advantage in the Corvette continuing to offer high end manuals as well as high end autos with paddles. Corvette C7 is rapidly becoming the only high end sports car with three pedals. Drivers celebrate!

DCT caliber 8 speeds just aren't in the C7 future for at least two years, if ever, and they will likely never get glowing reviews until well into the C8. The money, time, and market for such a high cost tranny just isn't there right now.

SCM_Crash

No... A DCT that handles the power and torque of a VW Jetta or Golf may cost $2K, but one that can handle an LS3 or LT1 isn't going to be remotely that cheap.

Think about it this way: The PDKs in the high powered Porsches cost over $15K. (When I worked for a Porsche shop, we priced them out to customers way beyond even that.) And those are PDKs for 500HP cars.

Being that the LT1 will *likely* make around 470HP +/- 10HP, you can bet your butt that the DCT that will handle the power of a LT1 is going to be quite a bit more expensive than $2-4K. Also, transmissions are built to handle Torque and that's really what they're rated by. Porsche's don't make as much low-end torque and hardly make as much top-end torque as the LT1, so you can imagine that this DCT will need to handle more than what the PDK can handle.


Just throwing that out there.

Raitzi

I would get DCT over manual because the car would be cheaper with DCT here. Porsches are cheaper with PDK because CO2 emission is lower with PDK compared to manual.

SCM_Crash

This makes sense.

johnglenntwo

If the C7 Z51 annihilates the 911 Carrara S's time at The Ring then all the contrary arguments are simultaneously going out the window!

b4i4getit

It won't annihilate the 911S. Just because you want it to does not mean it will.