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I guess mod friendly is a relative term.

Thanks for the info GPTourer!

 

Have you read anything about the new tranny? It isn't an auto, it is an automated dual clutch manual, so there will be no torque converter! Read the thread below about DSG.

 

Would a DCT be better than a manual? Hmm, shifting in milliseconds without disrupting power from the engine -- hence eliminating turbo lag... yeah I'd say that sounds like a good thing.

Wouldn't you?

I hate paddle shifters though. I know it's good to keep both hands on the wheel but I'd still rather row a shifter back and forth, even if it's just sending electronic signals to a computer to shift for me.

 

It will have a foward and back sequential shifter also.

 

The DCT wouldn't eliminate turbo lag. There remains separate ratios and therefore, shifting from one gear to the next will always result in a change in revs. Going up a gear (3->4 for example) will require that 4th is engaged at a lower rev than what it was when the car was in 3rd. So, since there will be a drop in revs, if your gear ratios are too different, it will drop too much and thus cause lag.

Where the DCT helps is that the period during which no/very little power is transferred to the gearbox (and henceforth the wheels) is reduced thus there is less interruption in power flow and as a result giving a more continuous accceleration. There are other things also where it is beneficial but turbo lag is not one of them.

To reduce the effect of turbo lag, you need more ratios. Arguably this is where DCT might help but indirectly. Since there's less interruption due to gear changes, you can have, for example 7 or more speeds. This will allow you to have a really tightly spaced ratios, thus keeping you in the most efficient region of the engine operation. Having so many gears in a plain manual tranny would mean you're spending too much time between gears that there's a significant period where you're not putting the power down.

To 'eliminate' the effects of lag properly, you'll need to go for a true CVT where the ratio of the transmission varies continuously. Sadly, I doubt those will be commonly available (in so far as evo's are common) that will be able to handle anything close to what people will want the evo to have. In the near future anyway.

For more info:
CVT - http://auto.howstuffworks.com/cvt.htm
DCT - http://auto.howstuffworks.com/dual-c...ansmission.htm

 

You've got to be kidding me... .

Do you really think the engineers are going to design the gear ratios so that each shift bogs the engine enough that your turbo will loose it's spool? It's not the ratios that cause the drop in boost. It's the throttle lift.

Do yourself a favor sometime, try test driving a turbo with an automatic transmission when you find a chance. A 4 speed auto shifts a lot slower than a DCT, yet even that manages to keep the turbo spooled up while shifting.

Ooo! I missed that bit! Thanks, I'm going to have to look that up.

 

Who is Manuel and what kind of trannies does he produce?

 

I agree. I remember an auto GS-T we had on out lot a while back that felt suprisingly good when I just was so sure it would be a dog. Of course it had a tiny T-25, but with the advancements Mitsu has made with MIVEC and twin scroll turbos, I'm pretty confident they won't have any problems keeping the revs up between shifts with the new trans.

 

First of all, what i mean by lag is the delay between vehicle's acceleration and the throttle input. In other words, you put your foot down and nothing much happens for a while. Turbo lag, therefore, I would use to mean lag as caused by the turbo. Either from inertial factors or its operating point.

(I perhaps did not make myself clear. I am not worried about revs dropping. I was saying that the revs drop anyway. And if the car is set up in such a way that next gear comes in in the lag-prone region, the lag will be there dct or no.)

Two common situations when lag is experienced - 1.) Accelerating and going up between gears and 2.) Low speed + high gear (overdriving) followed by a throttle input.

1.) When you go up a gear, you will always have to drop a few revs. You can't go from 3rd into 4th and keep the same revs. In well designed cars, the ratios let the vehicle operate within a high efficiency region. In turbo cars, this means beyond the laggy region. However, to do so, upshifts must happen at a high rpm - near redlline. In evo's nothing much happens before 3.5-4k rpm and so the ratios are such that if you shift at around redline (~7.5k) you slot into the next gear at around 5-5.5k rpm. While this is nice, not everyone redlines it in every gear all the time. If, for some reason, you shift early (short-shift) there is a possibility that you will enter the next gear at an rpm which lies in the laggy region. You may want to do this for a number of reasons. But when this happens, you will experience lag when you're in the next gear. This has nothing to do with whether the gearbox is a plain manual, DCT or even a conventional auto. So, in this case, it does not make sense to say that the DCT eliminates turbo lag.

2.) When you're driving in too high a gear than for optimum acceleration and you hoof it, you'd experience a lazier acceleration than your vehicle is capable of. If you have a clever enough control system, it will tell the gearbox that it needs to change down. Again, this happens regardless of gearbox type. (In a plain manual, the drive will change it down a gear or two.) While the DCT can change down gears quickly, it still takes an amount of time. So once you put your foot down, there will still be a slight heistation (see below) while the revs rise slowly (cos of the lag) for a bit then the computer thinks it needs to downshift then do so and the car shoots forward. So the lag is still there, you just feel a little less of it. Again, the DCT does nothing to eliminate the turbo lag. With a clever enough control system, it can reduce the effects of lag but it does not essentially eliminate the lag.

All in all, the thing that dictates the existence of turbo lag is the characteristics of the turbo combination, the engine and the transmission ratio. The DCT is in all practical sense a manual with intelligence and one that shifts extremely quickly. But it cannot eliminate turbo lag. A car that suffers from turbo lag when equipped with a normal manual will continue to do so (perhaps to a lesser extent) with a DCT.

p.s. I owned a turbo volvo with an auto for 3 years so and a Forester Sti for 2 years before that, i know what it's like. I've driven the Maser Quattroporte and know how crap the automated manual is. I've driven an A6 and a Bentley Conti GT and am mighty impressed. I think DCT's are great. They just don't eliminate turbo lag, that's all.

 

For Drag the DCT would be faster no contest. For Circuit racing it is also superior in both manual mode, and automatic mode only if you know the workings of your DCT to compensate for it's lack in certain situations where you need to tell it to hold a certain gear.

Judging what mitsu has said about the SST being superior to DSG, I'm definitely getting it. For one thing, like I mentioned before, it will outshift every traditional gearbox currently available including Formula 1 and WRC racing cars. It is banned technology in many races for its incredible advantages.

For those who only prefer the fun of rowing through gears, I can predict that aftermarket support will supply us with JGTC replica shift knobs and those huge WRC paddle shifters.

 

can you toe and heel with one of those automatic manuals transmissions?

 

You don't need to because the transmission\engine computer matches the revs for you.

 

Wow. You totally owned the guy.

 

no way that is sexy !!!! - so i learned to toe&heel for nothing uh? haha

 

No, I'm the one who didn't make himself clear, and I should apologize for that. No, of course the type of transmission used won't eliminate all turbo lag. I meant it would eliminate the lag one experiences while up-shifting under full throttle acceleration in a manual transmission car. Only and exclusively under that condition. Assuming the ratios would be as close to ideal as possible for maximum acceleration -- and with a car like this I don't think that's an unreasonable assumption. And even if it isn't eliminated completely, it's significantly reduced by comparison.

I don't want to start any arguments here, but I didn't think I had to be that specific.