Total Manual VS Step/Tip-Tronic

[k3nny]

I was just joking about MS . I find it useless to argue over the internet untill you really see it happen.

Sadly, the only DGS car in malaysia now is the VW golf.
Altough Audi pioneered the DSG development, VW is it's parent company.

The DSG can be found on the Audi A3 and the TT(new TT, havent seen any in malaysia yet). Both cars are not in malaysia yet...and even if it is, I doubt the pricing to be under 300k for either 1.

The DSG gearbox was designed by BorgWarner. The difference between the DSG box and other boxes is that the DSG uses 2 clutches. 1 for the odd gears and 1 for the even gears therefore enabling it to shift much faster and smoother than conventional gearboxes.


This is good in theory but in practice, upshifts are very fast, as fast as 8ms per upshift in order which is faster than BMW's present SMG II which clocks in at 80ms however downshifts are a different story.

The speed with upshifts are mostly attributed to the fact that while an odd gear clutch is engaged, ie:first gear, the even gear clutch is already on standby ready to shove itself in with the 2nd gear.

However with downshifts, this gearbox can take up to 600ms because it has to wait for the computer to blip the throttle to match the engine speed to the gearbox speed.

In the event that you want to change from 4th to 2nd or even 6th -2nd when approaching a sharp corner at a track, this can take up to 900ms. This is because the computer has to shift into an odd gear first with the other clutch before engaging the gear required/selected.

As it needed to package 2 clutches into a limited space, BorgWarner mutiplate clutches which are smaller in diameter than conventional clutches and such a complex assembly can be questionable with it comes to frequent track use or possibly high powers such as modifying the TT 3.2 to make higher powers.

 

[boggysv]

you go your info from autozine?

about the brog warner thing...VW and audi were the first customers to buy and proposed the technology. I believe that all 3 companies contributed to the development. If I'm not wrong, they have an agreement thet brog warner should not sell the technology to others for some time.

Power should not be an issue, since there are rumours that the new RS6 wil be using the DSG.

Too fast/abrupt a downshift might cause the car to be unstable. however, The 5th >2nd gear change seems a little too slow. HOpefully they will rectify the problem soon.

Waiting for the throttle to blip is a good thing, as it takes care of your car, and it shouldnt take too long. The light turbo engines with FSI have been proven to be responsive enough. Unless we are talking about produa kancils with 3 bangers.

We must always remember that car manufacturers would always take a conservative setup. This can be easily recitfied with a chip.

IMHO, the biggest problem is aftermarket support.
How are you supposed to adapt your GB if you switch to a different clutch plate?
How bad will you screw up your blipping configuration if you now have a bigger turbo with more lag?
And the biggest question, how much would it cost to repair one?

 

[si|verfish]

Ooohh...getting a bit too technical here, are we guys?

I sort of remember hearing that the DSG was used in racing by Audi (basically the VW group) and then after a while they developed it for use on road cars, starting with the TT32.

Anyway, if the Germans could build an auto box to take 700++ lb/ft of torque from Mercedes' mad 6.0 litre Bi-turbo engine, they could build a DSG box that can handle a lot of oommph. And sharpen up the downshift. Speaking of which I've never read about the DSG boxes shift times. All I've heard if how fast it changes. Any of you can provide some suitable links.

 

[boggysv]

http://www.autozine.org/technical_school/tech_index.htm

 

[si|verfish]

Thanks mate.

 

[k3nny]

Thanks mate.

I was just gonna post the link.. Hahaha

Very informative website with good explanations and illustrations..

Essentially, the more complex the assembly gets, the less we can expect to modify the car or at least, expect to incur higher costs in the process.


If the new RS6 is using it, we also have to realize the fact that it is possible the gearbox will be built with its programs and etc adapted to the power output and torque levels of the RS6.

Blipping the throttle is a good thing and if you mention that shifting from 5th to 2nd is quite slow, can u imagine 6th to 2nd where the gearbox has to first engage 5th and then 2nd?

Too fast and abrupt downshift will not cause the car to be unstable in the event that the throttle was blipped to the proper engine speed as the shift should not jerk or unsettle the car at all if the engine speed matches that of the gearbox speed.


Essentially with these boxes, if you were to go with an aftermarket turbo, some tuning house for Audi would sell the kit consisting of the turbo and also management for the engine and the transmission which is what alot of BMW aftermarket part manufacturers are now doing. Not so much the gearbox yet but the engine management.

 

[boggysv]

um....the RS6, it's just rumours, but hopefully it's gonna be real

rev matching is one thing, the sudden increase in engine braking is another.
I remember reading somewhere that downshifts shouldnt be too fast, esp in RWD cars...let me dig it up.

:D at least i feel like i belong to this thread, I suck at all other threads coz i dunno jack about japanese/malaysian cars

 

[si|verfish]

Well I'm not a science wiz but I think if you downshift too abruptly, you'll be unbalancing the car, the rear might loose traction and so on.

 

[speeddemon3500]

hey guys....
i read somewhere that a properly set up manual gear box has almost 95% efficiency. dunno how accurate that is but sounds a bit too good to be true to me.
anyway if u think clutchless manuals are bad, i personally think CVT gearboxes are way worse (for fast driving). like the one in the honda city. sometimes when u tekan the throttle, the car's speed increases but engine speed stays the same.
i heard they're quite fragile too

 

[k3nny]

Well I'm not a science wiz but I think if you downshift too abruptly, you'll be unbalancing the car, the rear might loose traction and so on.

This depends entirely on the gear spacing and the corresponding ratio's.

If i drove a DC5 R which has a very closely spaced 6 speed gearbox, on the assumption that 5th is spinning at 4500rpms, a downshift to 4th will see the engine spin at 5500rpms or maybe even a smaller increase in rpms and therefore a proper matching of the engine and gearbox speed by blipping the throttle will not unsettle the car.

I can't see why taking 600ms and taking 60ms to downshift a gear would make a difference in RWD, FWD, or 4WD unless of course the difference between those times would be the ability to properly match the engine speed to the gearbox speed to enable a smooth transition and yet even that is a problem if the downshift is occuring through a corner..

Hahahaha.. Malaysian and Japanese cars.. Dont forget Hyundai bro.. the new and rising manufacturer from the land of the rising sun.. oh wait, thats japan right? The land of the mata sepet people.. :)

 

[si|verfish]

I hope Audi will stick a DSG box into the new RS4. Currently it only has a manual. If it has that, it'll be my new dream car.