Silly question about sport mode

[admranger]

Originally Posted by bcredliner

You suppose right. It is from Dinan. Price is $299 for transmission software. Unless there has been a change Dinan products must be installed by a Dinan authorized shop. It should not take more than half an hour.

Whether it is too costly or a value depends on what one is trying to achieve. Software raises shift points in sport and economy modes, firmer and quicker shifts, full control in manual mode, automatically downshifts to third when stopping in manual mode and will shift automatically in manual mode if kick down switch is activated. I am very pleased with the benefits and think it is a great value because I like all that stuff.

Yeah, I was a bit (a bit?) pejorative there...sry.

Dinan engineers fine products, no doubt.

I don't have a problem with the current 'learned' shift program in my X5 in normal mode. I like sport when I want to do an italian tuneup, with the exception of the slowing down to a stop smoothly issue. If the Dinan software solves that issue, then it would be worth it to me. If it doesn't, then I'm good with what I have. Sometimes not knowing what's available is better for me. Definitely better for my wallet.

[Qsilver7]

As has already been discussed & mentioned...the STEPTRONIC transmission and ATC (adaptive transmission control) sport mode and adaptive mode on the e53 is basically a remap of the shifting patterns of the transmission. All to get the most from the engines power reserves. There are no other systems involved (like suspension or brakes etc)...just transmission shifting and DME engine intervention:

(from owners manual)

[edogg]

Interesting information about the DME retarding ignition timing. Is that why I feel more engine/compression braking when I let off the gas pedal?

[JCL]

Originally Posted by edogg

Interesting information about the DME retarding ignition timing. Is that why I feel more engine/compression braking when I let off the gas pedal?

No. You feel more engine braking because the shifting program has been changed to hold a lower gear longer.

The DME changes to engine timing, and the DDE changes to fuel injection, last only milliseconds. They occur during the shift, not before or after it. During the shift, engine power is automatically reduced by the DDE and DME to make the shift smoother (in all modes). It makes it feel smoother, reduces the load on the clutches, makes the transmission last longer, and keeps the fluid cleaner, all by reducing slipping of the clutch plates.

[Qsilver7]

I would presume that to be the case.

[g300d]

Again, cool info on the nuances that make a BMW a BMW.

[edogg]

I've pushed into the kick down feature while in D and found it pretty jerky and rough. So I don't do it very often. If I need to drive like a bat outta hell, I put it in Sport mode and the shifts are much smoother.



This is fantastic info! Thanks for all the replies and tying the technical reasons to the feeling.


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[srmmmm]

I have also "sensed" a change in transmission behavior when towing as well. I know the vehicle is aware of the trailer because of the wiring harness load, so I am thinking sport mode or some degree of it, is automatically engaged when I've got the trailer out back. Any thoughts?

2002 X5 3.0 252,000 miles
2004 325i 113,000 miles

[admranger]

Originally Posted by srmmmm

I have also "sensed" a change in transmission behavior when towing as well. I know the vehicle is aware of the trailer because of the wiring harness load, so I am thinking sport mode or some degree of it, is automatically engaged when I've got the trailer out back. Any thoughts?

2002 X5 3.0 252,000 miles
2004 325i 113,000 miles

Perhaps it is locking up the torque converter faster? That would keep trans fluid temps down I think.

[JCL]

Originally Posted by srmmmm

I have also "sensed" a change in transmission behavior when towing as well. I know the vehicle is aware of the trailer because of the wiring harness load, so I am thinking sport mode or some degree of it, is automatically engaged when I've got the trailer out back. Any thoughts?

2002 X5 3.0 252,000 miles
2004 325i 113,000 miles

Connecting a trailer has never been reported as a modifier of the transmission shifting program, so no, I don't think it changes to a tow mode.

What the transmission does do is consider vehicle speed, throttle position, and so on when selecting a gear, so it is entirely to be expected that adding drag (eg a trailer) and thus requiring more throttle at a given speed will change shifting characteristics.