Mister Two

Huh? Sequential manual transmission = SMT = single-clutched automated transmission = LFA's tranny = all modern race cars' tranny.

gengar

Tiff Needell too, in the 5th Gear review.


I actually wouldn't be surprised if PDK eventually makes it to the GT3. Porsche engineers have made statements implying that they're in the process of developing PDK for the GT3. Considering PDK is even an option on more "hardcore" models like the Boxster Spyder, and that pricing it in as an option fits in with Porsche's business model, I expect PDK to make an appearance on the next gen 911 GT3. Of course I could be wrong........


The real issue is the weight. Any dual-clutch that can handle racecar hp/torque is going to weigh at least 100kg more than a sequential clutchless manual. Even the Getrag dual-clutch that is only rated for around 400hp is already ~100kg more than a manual - I have no idea (and almost fear) how much, say, the PDK in the 911 Turbo weighs. That 100kg+ weight difference is approaching 10% of say, a GT3 RSR or Cup car. With all the attention that racecar operators pay to reducing weight, it should be no surprise that they would never accept dual-clutch in their vehicles. It's less of an issue in a 4500lb tank like a Veyron - or for that matter, the 458 which is already 200kg+ heavier than the 360 and for a company like Ferrari that's sold out to the horsepower and Nürburgring lap time wars.

This is probably also one reason it's not on the LFA. The entire CFRP redesign supposedly saved around 100kg. Switching to dual-clutch would immediately eliminate the weight benefit of going to CFRP.


Racecars may use a clutchless sequential that differs from the sequential automatics, but the racecars still don't use DSG. There's a reason.

BNR34

iTrader: (1)

Yes I too predict PDK will be an option on all future Porsche models....GT3, GT2....etc. 918 is PDK only. The hardcore M3 GTS is DCT only.

I feel the performance benefits of a DCT out weight the weight penalty. And the LFA is not that light of a car, C&D weighed it at 35XX lbs. It is not like a 1300 lbs Ariel Atom or a 1900 lbs Elise.

Yes there is a reason, but not for above stated reasons.

BNR34

iTrader: (1)

I can understand the confusion, I don't blame you

05RollaXRS

No way!!!! The 250 pounds are never going to be offset by marginally faster shift speed. The LFA transmission already shifts incredibly fast from what every review has said. That is a huge hit on the power to weight ratio of the car. Like I stated above, DCT has huge downsides on the race track where the whole concept is flawed of pre-selecting another gear based on "guessing" what the user is going to do next. A single clutch shifts far more consistently with the same speed.

Secondly, like SickLex and Gengar (who actually has an LFA on order. not just arguing over the net) described, many enthusiasts like Chris Harris and Tiff Needel of Fifth gear (also Clarkson from TopGear) hate dual-clutch transmission for their automatic-like feel.

I have driven a DSG GTI and it was plain boring and I had a hard time telling a DSG transmission apart from a torque converted automatic.

Case in point, they both have their own advantages and Lexus decided to side with the advantages the single-clutch has to offer despite starting off with a Borg-Warner dual clutch unit.

LexFather

I would not bring up the Veyron. Their dual clutch has some patents and it is truly one of a kind since it has to handle all that power. From my understanding its made by a British company. I don't think Veyron owners care about "feel" anyway.

Mister Two

Clarify my "confusion" then, please?

LexFather

Ladies and Gents play nicely

In regards to Porsche, yes, I have read the same about PDK spreading across the line. I just hope it remains AN OPTION and not a standard feature.

05RollaXRS

I also have heard Porsche has been working on a 7 speed manual transmission.

BNR34

iTrader: (1)

I am playing nice

Porsche is trying to phase in the PDK slowly, there are still a lot of clutch pedal lovers who are resisting the change. But the clutch pedal will go away eventually just like the cassette and carburetor. It is not only for faster shift times, the biggest reason is for improved efficiency. Companies are doing everything they can to meet the high government mandated MPG requirement.

05RollaXRS

That has been said since the 70s when 3 speed automatics came out that "manual will go away".

For one, it has been said Porsche is actually developing 7 speed manual transmission and also driving a performance car is all about entertainment and sheer joy of driving. Nothing gives a higher level of interaction and control like a manual transmission does with all four limbs being used.

Manual is not going anywhere. It will just become far more exclusive to very performance oriented cars that are not focused on being daily driven and offered by brands like Porsche since Porsche's huge chunk of sales on 911, Cayman and Boxster are indeed manual transmissions. Aston Martin also offers a manual transmission on all of its models. As a matter of fact the new Audi RS5 sales have suffered because no manual transmission was offered for it.

TRDFantasy

That is a very bold thing to say there. Do you have any proof of this?

The fact is the LFA project had NO time OR budget limitations. That is why the project from start to finish took 10 years. That is why years into the project, they switched from an aluminum chassis and body to a carbon fiber one. The single clutch transmission decision and development began very early in the LFA project.

You're not "telling it like it is", you're merely stating your opinion. I don't understand what exactly you're trying to say here. Do you know the LFA's V10 has a better torque curve than the Ferrari 458, without using direct injection? HP isn't everything, nor are paper specs. HP and torque curves matter a lot as well. Also do you realize the LFA's V10 is as small as 3-3.5L V5, and is extremely lightweight (quite a bit lighter than the Carrera GT's V10 for comparison)? Do you also realize the LFA's V10 meets Euro 5 emissions without direct injection?

I am pretty sure that adding direct injection would make the LFA's V10 not sound as good.

Both the Carrera GT and LFA are arguably some of the best-sounding supercars ever made. Also, can you name me at least one supercar or sports car that uses direct injection and has an amazing sound? This is not a coincidence.

Also as 05RollaXRS pointed out, direct injection brings other issues such as carbon build up.

As for the transmission, you DO realize the Carrera GT has an single clutch transmission right?

I do believe Toyota purposely chose a single clutch for more "feel", not because of supposedly limited R&D costs or other reasons like that.

Yes not everyone likes single clutch, but not everyone likes dual clutch either. You can never please everyone. Toyota made a choice for the LFA to be more raw and visceral, while still being comfortable.

You have to understand what Toyota's goal was with the LFA.

05RollaXRS

Also, the front engine/rear wheel drive midship layout LFA has is far more expensive to build than a rear engine/rear wheel drive midship layout that typical entry level Ferraris have. LFA has a carbon fiber torque tube just for this reason.

Also, the revolutionary things such as a 1.26: 1 counter gearset that adds torque multiplication (increases overall final drive from 3.42:1 to 4.3:1) and also helps achieve a lower center of gravity.

Inherently, front-engine/RWD midship layout is far superior in terms of stability than the rear-engine/RWD midship layout and gives a much more neutral balance inherently. Lexus achieved that magic number thanks to its super light V10 that weighs as much as a 3.0 Liter V6.

It is just that most companies opt for the rear-engine/RWD layout to achieve that 62/48 magic distribution simply because it is cheaper and easier to achieve.

rominl

iTrader: (4)

not trying to be argumentative, coz' i don't think either side has solid answers and both sides have valid points. it's mainly about talk of what-ifs on the lfa and how things might be different. toyota made their choices, they might think it's the best, but at the same time they aren't offering any figures to disprove otherwise.

but...

so, suddenly sound > performance?

and carrera gt is a car that's 7 yrs old. i am not sure if using single clutch setup on that car is a good idea?

TF109B

The LFA is fine, we'll see when the production car hits.





Take a close look at the slalom and skidpad numbers, and the Carrera GT is said to be one of the best handling cars in the world.