DCT Sport Button Question

[DeepOvertone]

Hello all.

I was hoping someone here could give me a technical answer on what exactly the sport button on the DCT car does. I know it makes it drive more sportily but I want to know HOW it affects the various paramaters in order to make it feel more sporty. Thanks.

[Harlequin]

Changes the throttle sensitivity and raises the shift points.

[DeepOvertone]

I could definitely tell that it changed the shift points but I was wondering how it controlled the throttle sensetivity. I wasn't sure if it just remapped the throttle or if it had some effect on the wastegate position. Also, I was curious if it changed the speed at which it releases the clutch. I found that the shifts felt sharper while in sport mode. It could just be my imagination though.

[Harlequin]

It does make the shifts more aggressive as well but that always seemed to me to be much more noticeable when you flick the shifter over to S as well...

[DeepOvertone]

Well, I find that it holds gears much longer in S. I'm not a fan of the way S mode holds the gears for anything but track purposes. Its far too agressive for street use. IMHO at least.

[bmw0bsession]

it changes gears significantly faster, you can hear it in the exhaust. Also, you should be changing gears at about 6k rpm

[Harlequin]

Originally Posted by DeepOvertone

Well, I find that it holds gears much longer in S. I'm not a fan of the way S mode holds the gears for anything but track purposes. Its far too agressive for street use. IMHO at least.

I took to driving it in SM Mode. Put it in S and then change gears manually. 95% of the time...

Originally Posted by bmw0bsession

Also, you should be changing gears at about 6k rpm

That's an extremely broad statement.

I'd say "If you are trying to get the fastest acceleration out of the car then you should be changing at around 6k - maybe a bit lower."

If you are driving normally, in traffic, then 6k is ridiculous - more like 2-2.5k...

[DeepOvertone]

That's an extremely broad statement.

I'd say "If you are trying to get the fastest acceleration out of the car then you should be changing at around 6k - maybe a bit lower."

If you are driving normally, in traffic, then 6k is ridiculous - more like 2-2.5k...

Haha.. I'm sure he meant for maximum acceleration.

[BEAR-AvHistory]

I don't believe it changes the throttle parameters, can't see that on any of my logs. Throttle was only effected by ECU specific changes through the JB4.

But each of the 6 stages does increase the RPM auto shift point & intensity of the shift up to Manual/Sport button.

Agree the N55 is all done by 6000rpm & N54 can run out in my case to 6250rpm.

[DeepOvertone]

It HAS to change something that affects the throttle(even if it doesnt affect the throttle itself). It is MUCH more responsive when it comes to throttle inputs. I read that one of the turbo cars varies the percent that the waste gates stay closed or open therby keeping boost pressure built up so that when you do open the throttle its instantly available. My car only has one level of sport mode. On or Off. So for me it only affects shift points, shift speed and something to do with throttle response. I'm really looking for technical details though. I want to know EXACTLY what the computer changes to get those effects.

[Andrewcoja]

The manual says:

Driving dynamics control
The driving dynamics control permits you, at
the push of a button, to have your BMW react in
an even more sporty fashion when driving:
> Optimal use is made of the engine's speed
range.
> Gear changes occur more quickly.
> The engine reacts more spontaneously to
accelerator pedal movements.

So the throttle by wire reacts quicker than in normal drive mode where it largely ignores your throttle inputs until it's sure you wanted to accelerate three seconds ago.

[DeepOvertone]

Originally Posted by Andrewcoja

The manual says:

Driving dynamics control
The driving dynamics control permits you, at
the push of a button, to have your BMW react in
an even more sporty fashion when driving:
> Optimal use is made of the engine's speed
range.
> Gear changes occur more quickly.
> The engine reacts more spontaneously to
accelerator pedal movements.

So the throttle by wire reacts quicker than in normal drive mode where it largely ignores your throttle inputs until it's sure you wanted to accelerate three seconds ago.

Yeah, I read that but I want to know more technicaly what it does.

[jester17]

...and, just to check, the sport mode -- regardless of mode, S or M -- uses more fuel, correct?

[BEAR-AvHistory]

A car that is held in a lower gear will reacts quicker accelerator pedal movements.

In a 40/45mph cruise I am in 5th or 6th instead of 7th with the button in. The car will react quicker when I push the throttle because of the gearing. Does the car get jerker part throttle off the line in S or M/S mode?

I know we can modify the throttle mapping with the JB4 but to re-map the trans is a different piece of software that is transmission specific a Alpinia Trans Flash. ESS also has a DCT tune about $900 for the M3 version.

The M3 sport button does a lot of stuff but I believe the 135/335 is pretty basic. If the throttle is being re-mapped I wonder why it does not show up in the logs.

[Tricki]

When in sports mode the throttle response is great until you push the DTC button then the sports mode is deactivated.... Try it out , it's annoying !!

[bmw0bsession]

Originally Posted by Harlequin

I took to driving it in SM Mode. Put it in S and then change gears manually. 95% of the time...



That's an extremely broad statement.

I'd say "If you are trying to get the fastest acceleration out of the car then you should be changing at around 6k - maybe a bit lower."

If you are driving normally, in traffic, then 6k is ridiculous - more like 2-2.5k...

Sorry failed to say during WOT lol

[alexmtl_135i]

Originally Posted by Tricki

When in sports mode the throttle response is great until you push the DTC button then the sports mode is deactivated.... Try it out , it's annoying !!

I confirm, it's annoying. I've raised the topic on an earlier post: http://www.1addicts.com/forums/showthread.php?t=730033

Originally Posted by BEAR-AvHistory

A car that is held in a lower gear will reacts quicker accelerator pedal movements.

In a 40/45mph cruise I am in 5th or 6th instead of 7th with the button in. The car will react quicker when I push the throttle because of the gearing. Does the car get jerker part throttle off the line in S or M/S mode?

If the throttle is being re-mapped I wonder why it does not show up in the logs.

The throttle is definitely remapped, not sure why it doesn't show up in the logs. An easy test is to go in manual mode, and try sport ON vs OFF. You'll see a slight change in responsiveness that is not linked to the gear you're in.

Originally Posted by jester17

...and, just to check, the sport mode -- regardless of mode, S or M -- uses more fuel, correct?

Not in my experience and tests on highways, which is why I believe it's just a throttle remapping. You may use more fuel when in Sport mode because you enjoy the car more though

[Artovs]

I agree. This is frustrating. It likely only affects perceived throttle position. I.E. When Sport button is on make 10% throttle = 20% throttle. WOT has always felt the same to me regardless of Sport/DTC/everything off.

The craziest part to me is that in order to use Launch Control, we have to push DTC once (apparently rendering Sport button useless), go into Manual mode ANDDD push the Sport mode button. I think that last bit is just there to keep people sane, but what gives??

Just drive with everything off and enjoy your cars, I guess. Unless there is a BMW tech out there who can enlighten us.

[Andrewcoja]

Originally Posted by Artovs

I agree. This is frustrating. It likely only affects perceived throttle position. I.E. When Sport button is on make 10% throttle = 20% throttle. WOT has always felt the same to me regardless of Sport/DTC/everything off.

The craziest part to me is that in order to use Launch Control, we have to push DTC once (apparently rendering Sport button useless), go into Manual mode ANDDD push the Sport mode button. I think that last bit is just there to keep people sane, but what gives??

Just drive with everything off and enjoy your cars, I guess. Unless there is a BMW tech out there who can enlighten us.

It's just another bit to make sure you really want launch control. Chances are, you aren't normally going to left foot brake, then hit DTC, then hit sport then hit manual. It's just a bunch of steps to make sure you really want to use it.

[Allen@MOTIV]

There are two seperate throttle mapping tables in the DME and it selects which to use based on which mode you're in. This actually provides us tuners with an awesome opportunity to create two separate throttle maps which can better suited to your driving styles. One refined for use the roads and one designed for track use.