rgregory

I was speaking the outright shift speed. In sport mode the shift speed of the Gallardo a first generation single clutch SMG is still good and probably withing 40-50 MS of a DCT. If the Aventador can shift basically as fast as a DCT with a single clutch it can be done without the whole DCT complexity.

The quirkiness of the e-gear is worked out with refinement. Mine went 24k miles on the original clutch and has 34k on the current later gen clutch that is supposed to last much longer than the original. I have driven M3s with SMG and yes it was worlds better in refinement than egear.

Steven Beaver

I went from an A8 GS to a PDK Porsche. There is no comparison. Whether city cruising or driving aggressively the PDK is faster, smoother and way more enjoyable. The C7 & C8 need a good DCT. Might make me switch back.

dexterkatt

You Gallardo does not have a automatic tranny. It is a computer assisted manual tranny. It has a regular clutch.

Jackie Chiles

Questions for those who know:

Why wouldn't GM use a version of the A10 already used in the Camaro?

How does that A10 stack up against a proper DCT?

I haven't driven the A10 or any DCT for that matter, and my M2 has the manual, but I agree with one of the posters above that a racey auto trans could be tons of fun.

k wright

I hope that the magnetorheologic patents that GM holds for use in an automotive clutch are deployed on this car for drivers that don't want a stick shift.

The MR clutch has infinite adjustability and sub-second reaction times and 1 moving part....that doesn't wear out.

rgregory

Um when did I ever say it had an automatic? I know what kind of transmissions are in my cars.

Quinten33

There’s this guy Mike who has a YouTube page called StreetSpeed717, you may have heard of him or seen his crazy wrapped Corvettes. He has a Z06 with the automatic and his buddy who also has a YouTube channel owns a 10-Speed ZL1. Everyone who has been in both cars agrees that the 10-Speed is better in every aspect. The paddles are instant in response, you can barely feel the shifts, it is always in the power band, and it’s just smooth. Mike recently purchased a McLaren 570s, a car that comes with a biturbo v8 and a DCT. He says that the dual Clutch is leagues above his 8-Speed and that it shifts quicker than anything he’s ever been in. He also said that it’s smooth and feels far more refined than the torque converter autos and that it felt like a racecar, and that means a lot considering that his C7 Z06 is used for drag racing and has 800+lb ft of torque at the wheels. I have very little knowledge on the mechanics and design of a transmission, but could GM turn their 10-Speed into a DCT? That would be better than a Porsche PDK.

rgregory

If GM goes the DCT route their best bet would be to source a DTC from a manufacturer that already makes them, McLaren doesn't make their own transmissions.

I drove a 570s and loved it, the transmission is worlds ahead in refinement than my Gallardo. In general the 570 as a whole made my car feel old.

Drunkonunleaded

People seem to overlook that Tremec has had a DCT for years:

http://www.tremec.com/anexos/Literat...ansmission.pdf

I would suspect that this was meant for the C7 (Z06 perhaps?) but cut due to costs.

Rkreigh

outsource and run the latest audi/gallardo gear box

it's down to under 10k, and while that's more expensive that the gm crap, it's proven, and not that much

and retain the 6 spd with a ricardo box from the ford gt

get the numbers up and the cost will come down

gm doesn't need to make everything, they just need to find the best and integrate well

dznr723

Ferrari 488’s don’t seem to have these problems

vetteman41960

I have a 458 Italia and it has a DCT. You are correct that it does not have the same issue as the Lamborghini Gallardo. The Lamborghini has a single clutch that is absolutely terrible. I also owned a Gallardo and had to replace the clutch at 9k miles. With the Lambo you have to be in neutral at every stop light. If you sit with car in 1st gear for more than 10 second the computer puts car in neutral to try and prevent clutch wear. Also due to the delay from a dead stop to clutch engagement the launch control is very hard on the drive train.

Lamborghini and Ferrari 430 were both using these automated computer controlled single clutch and old technology. That's way the 458 and 488 went to a true DCT.

The Lambo is horrible in auto mode and has very hard shifts in manual mode. Plus there is a significant delay from a dead stop from the time you take your foot off the brake and the clutch engages. This drove me nuts. A super car with a delay from a dead stop while you noticeable wait for the clutch to engage. You cannot just put the pedal to the floor from a dead stop you 1st have to wait for it to engage and do a small roll out before you can put the pedal to the floor. Otherwise it bangs the crap out of the drive train.

The 458 has none of these issue. It is very smooth in auto mode and no delay from a dead stop. Plus you can drive it like any other TC trans. The shifts are lighting fast both up and down from paddle pull to gear change. In fact there so quick I cannot perceive any delay at all. It seem instant. Now I know that it's does take milla second but it's so fast that a guy like me cannot tell it's not instant.

I also own a 2016 Callaway SC757 with A8. Love my Vett but the delay from paddle pull to upshot or down shift is very evident. Both the Lambo with the old single automated style trans and the Ferrari 458 DCT are night and day fasted than the A8 shift.

In fact I find it hard in manual shift mode that you have to make the upshift well before you get to 5700 rmp for the car to shift before it hits the Rev limiter due to the delay from pI'll to engage. Also make the shift light nothing more tHan a gimmic in the VETTE.. Just a horrible delay both up and down in manual mode. The Vett should have specific rmp which light up the shift lights so it's know to the driver. No where does GM give that information.

In the 458 1 light on at 5200 2nd at 6200 3 at 7200
4 at 8200 5th and final light 8950 rpm. When you pull the paddle at 8950rpm the shift is completed before you hit the 9200 rpm limiter
​​​​

I am as big as a Corvette fan boy as there is. The Callaway is number 12 for me. But folks that say the A8 is comparable to a PDK or DCT like in the 458 have never driving a well sorted DCT.

I will say that for just cruising around town that the Callaway with the A8 has a smoother and more comfortable shift than either the Lamborghini or the Ferrari. In fact it's great for just normal cruise around town or on the highway.

I wish GM would have made the performance shift mode in the A8 a feature that the drive could engage and disengage at will rather than let the car try to figure out the drivers intent and how he want the car to shift at any given moment.

That alone would be a big improvement over what it is now.


GM must go DCT as an option in the C8 if it wants to be taken seriously as a world class super car.

Make it a 10k option so those who want the performance of a DCT can have it I'd they want to pay for it and for those that don't then they can have a TC trans.

GM please give us options and jsu charge for it.

I would think that they make a A8 or a10 standard and if the customer want a manual transmission charge extra for it . Customer want a DCT charge extra for it.

Hopefully the upper range of the mid engine C8 will offer more bespoke options that should be available on car costing 150k plus.

JerriVette

I agree offer a dct and let corvette buyers pay for it...offer the manual and call it day..I believe GM pays a million per drivetrain variant in government testing or so it's been said.

Just dump the torque converter transmission for the corvette.

Keep the torque converter automatic for the Cadillac version of the rear mid engine sports car....

rgregory

Look at the miles Ferrari 488s get a year compared to the average Vette. If the other poster here that had a Gallardo and killed his clutch in 9k miles and I got 24k on the original and over 34k on the second and still going shows you that people can ruin an automated clutch at different rates. My concern for GM is more about automated clutch than DCT or a single clutch.

Get in an automated clutch and drive it like an automatic you can destroy it. Yes software is getting better but Ferrari drivers are not attempting brake stands nor are they creeping them along in rush hour traffic daily.

dznr723

Yes, all true. I had a manual 430, then a 458 and now a 488. My mileage probably wasn't anywhere near what the Vette guys drive.

roadbike56

Introducing a new Corvette is a big deal to develop. I think after the A8, GM will want to go with a proven transmission. That means an A10. I'd be surprised if a DCT is used in the Vette at least initially. Now down the road, maybe, but I see an A10 being the transmission of choice the first year for the ME.

JerriVette

Porsches PdK is indestructible...even with thousands of launch control abuses..

If Porsche can do that. GM can as well.

What Ferrari dct or especially Lamborghini s single clutch can not withstand is relatively relevant to what Porsche or GM can accomplish with regards to daily driver reliability in a dual clutch transmission.

I'm not saying GM will or won't but using the Lamborghini single clutch automatied transmission as a basis of any logic tends to have its flaws.

Single clutch automated manuals were especially unreliable even for BMW.

NoOne

Here is the take away.

People who have not driven a PDK/DCT say the regular auto is good enough.

People who have driven a PDK/DCT know better. I doubt you take any of the naysayers and put them in a car with a good DCT/PDK and they come out of thinking the TC trans is good enough.

Nobody who has any interest in performance at all after driving both will say the TC trans is good enough.

The Lambo SCT is an Audi design I believe and was used in the first year or two of the R8 until they moved to a DCT since they shared a common platform.

The PDK/Audi DCT are pretty closely related especially in the lower powered cars.

The only thing I've driven even remotely close is the 9 speed mutli-clutch unit in the AMG cars. I only spent 30 minutes in the car and it was pretty close but without a lot of time not sure if its direct replacement. From my understanding is its a standard transmission and they replace the TC with a clutch pack which is not the same as a true DCT but I was pretty impressed by it.

ByByBMW

I learned this lesson almost 4 years ago when I drove my first Porsche. It had the PDK and it was a pure epiphany. Up until then there was no way I would own a sports/performance car that had an automated transmission.
If GM can come close to a Porsche PDK, I will be very tempted to switch back. Yes, I bought that Porsche.

JerriVette

Mercedes converted their traditional torque converter automatic planetary gearbox with computer controlled clutches.

I drove a renntech Sl63 or 62 I don't remember which and it's MCT was excellent. I believe it was an advance,ent over the traditional torque converter transmission,

The dual clutches seemed to be a further advance as Mercedes has moved from planetary computer controlled gearboxes without a torque converters to a true dual clutch ..