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-   -   Need to confirm with my understanding on DHP and DDC (http://www.bimmerfest.com/forums/showthread.php?t=712045)

amaggie05 07-29-2013 12:48 PM

Need to confirm with my understanding on DHP and DDC
 
Ok, I read a lot of threads on this topic, and everybody seems to have their own understanding.

Here's what I gathered, and please point out if they are true or not:

Non-DHP X3:
1. No realtime/dynamic change to the suspension to improve ride quality.
2. Different modes only change shift points, throttle etc, but not firmness of the suspension.

DHP X3:
1. Dynamic adjustment of suspension according to road conditions.
2. Different modes also changes suspension firmness.
3. Most people choose DHP for improved sportier ride, rather than smoother rider in comfort mode.

p/s. We have a lot of local roads with cracks and ridges, how much will DHP improve the ride? Will non-DHP X3 cope well with such road conditions?

thanks for any inputs.

Liverman 07-29-2013 05:55 PM

Quote:

Originally Posted by amaggie05 (Post 7739720)

Non-DHP X3:
2. Different modes only change shift points, throttle etc, but not firmness of the suspension.

The steering response is also changed. In Sport mode, since the steering response has changed, it can feel like the suspension has changed (which it has not).

I live in Colorado, rough roads are the norm. I do not have any extra suspension options. I like the ride just fine and have no problem with the handling.

Anfänger 07-30-2013 08:48 AM

Quote:

Originally Posted by Liverman (Post 7740348)
The steering response is also changed.

I don't understand how this is possible without DHP. I know that Variable Sport Steering is only available with the DHP installed, so is it something else that you are perceiving?

billyk 07-30-2013 01:59 PM

Please correct me if I'm wrong, I did research and test drove non ZDH X3's recently.

With ZDH (dynamic handling pkg), you'll have Variable sport steering, and "Performance Control" and Dynamic Dampers. It is a whole package. Then switching drive mode will change
- steering weight (by Variable steering)
- throttle mapping and shift point
- Handling (Performance control - "increase agility")
- suspension (if you opt for Dynamic damper)

If you do NOT have the ZDH, you wouldn't have variable steering, dynamic dampers or performance control. (Base on the US ZDH). Then drive mode switch only get you difference behavior with
- throttle response
- transmission behavior and shift points



http://www.bmw.com/com/en/newvehicle...ics/index.html

amaggie05 07-30-2013 03:09 PM

thank you for all your replies. I'm surprised that after so many threads in this topic, still not many people get a good grip on it.

One more question, for people who wants this DHP, are you looking to get improved comfort in comfort mode or more agility in sports mode? how much more comfortable of a ride does the package provide? wife is concerned about this question.

Anfänger 07-30-2013 03:13 PM

Billyk, agreed, except for one detail:

Quote:

Originally Posted by billyk (Post 7742015)
If you do NOT have the ZDH, you wouldn't have variable steering, dynamic dampers or performance control. (Base on the US ZDH).

The MSport package (ZMP) also offers performance control—if you order both ZDH and ZMP, you get a $100 discount in recognition of the redundancy.

02420X3 07-30-2013 03:54 PM

Never having driven a non-DHP X3, I don't know if you get improved comfort in comfort mode. I do know that you get a stiffer, less comfortable ride in sports mode. I bought DHP for Sports mode.

Liverman 07-30-2013 03:57 PM

Quote:

Originally Posted by Anfänger (Post 7741319)
I don't understand how this is possible without DHP. I know that Variable Sport Steering is only available with the DHP installed, so is it something else that you are perceiving?

from the f25 training

I'll post a link when I get a chance. They are posted on the other x3 forum

Liverman 07-30-2013 09:26 PM

Quote:

Originally Posted by Liverman (Post 7742232)
from the f25 training

I'll post a link when I get a chance. They are posted on the other x3 forum

http://prodcds.bmwuniversity.com/lib...20Dynamics.pdf

page 66

Vortec4800 07-30-2013 11:21 PM

The variable steering doesn't mean what you think it means. The variable steering means the steering ratio is different in the center compared to the edges of the rack. Regardless of whether you have the variable steering, the electronic rack can change the steering weight on the fly, which is why you get the steering feel change with or without the DHP.

Here is an excerpt from that PDF in the previous post:

Quote:

The optional equipment "Variable sport steering" (SA 2VL) is available for the F25 as an alternative to the basic version of the EPS. This is the first steering system available on the market to combine the benefits of an extremely direct, variable steering gear ratio with the operating principle of EPS steering.
The variable sport steering increases ride comfort and also agility. The direct ratio reduces the total steering angle, i.e. the number of steering wheel revolutions from steering stop to steering stop, by roughly 25%. This therefore increases comfort during driving manoeuvres that require larger steering angles, e.g. when parking, turning off or turning.
If you look on page 45 of that document there is a chart that explains it better.

Anfänger 07-31-2013 06:03 AM

Quote:

Originally Posted by Vortec4800 (Post 7743080)
The variable steering means the steering ratio is different in the center compared to the edges of the rack.

It's called Variable Sport Steering for good reason. Without VSS the gearing geometry is constant; with VSS it is variable. With VSS the number of turns lock to lock is reduced, enhancing responsiveness as a tradeoff with sensitivity. To avoid making it too twitchy for driving in a straight line, the VSS effect (i.e., the gear ratio) is progressively increased at progressively greater steering angles. It reaches its maximum ratio at 90 deg, but it is still noticeable at narrower angles. So it's great for a hairpin bend, but it is also great for suddenly steering away from a pothole, or driving along a winding road. And you don't get this unless you have DHP.

Quote:

Originally Posted by Vortec4800 (Post 7743080)
Regardless of whether you have the variable steering, the electronic rack can change the steering weight on the fly, which is why you get the steering feel change with or without the DHP.

So in sport mode the torque sensor feedback is amplified? I couldn't see this written anywhere for the X3, though the table Liverman referred does support the idea. On the F30 blog it has generally been concluded that Sport mode only amplifies VSS sensitivity, based on comments like this one from BMW's blurb about "Sport Mode":

"If variable sport steering is chosen, the assistance from power steering is reduced, which ensures a more direct feeling of steering control".

Vortec4800 07-31-2013 11:55 AM

Quote:

Originally Posted by Anfänger (Post 7743335)
It's called Variable Sport Steering for good reason. Without VSS the gearing geometry is constant; with VSS it is variable. With VSS the number of turns lock to lock is reduced, enhancing responsiveness as a tradeoff with sensitivity. To avoid making it too twitchy for driving in a straight line, the VSS effect (i.e., the gear ratio) is progressively increased at progressively greater steering angles. It reaches its maximum ratio at 90 deg, but it is still noticeable at narrower angles. So it's great for a hairpin bend, but it is also great for suddenly steering away from a pothole, or driving along a winding road. And you don't get this unless you have DHP.



So in sport mode the torque sensor feedback is amplified? I couldn't see this written anywhere for the X3, though the table Liverman referred does support the idea. On the F30 blog it has generally been concluded that Sport mode only amplifies VSS sensitivity, based on comments like this one from BMW's blurb about "Sport Mode":

"If variable sport steering is chosen, the assistance from power steering is reduced, which ensures a more direct feeling of steering control".

This is exactly right.

I have DHP, and in mine the weight of the steering definitely feels heavier. The sensitivity/responsiveness doesn't feel different in sport mode, I believe the VSS is "enabled" all the time. From what I've heard from other people without DHP, the weight of the wheel feels heavier in sport mode for them too, which supports the idea that the feedback is amplified with or without VSS, but they wouldn't have the variable sensitivity based on steering angle.

This is all a bit confusing to write out. I think to dumb it down, DHP gives you sportier and more responsive steering in general, without DHP you do still get a bit more feedback from the wheel in sport mode.

Stitches 07-31-2013 05:43 PM

Quote:

Originally Posted by amaggie05 (Post 7742147)
thank you for all your replies. I'm surprised that after so many threads in this topic, still not many people get a good grip on it.

One more question, for people who wants this DHP, are you looking to get improved comfort in comfort mode or more agility in sports mode? how much more comfortable of a ride does the package provide? wife is concerned about this question.

I chose this feature for the added comfort. I bought it "feel unfelt" as I could not find a test drive vehicle equipped with it. I went on faith, based on feedback from these boards.

Sorry I can't offer an opinion on how much of a difference from a non-DHP vehicle. Once I got my new vehicle I did not drive a non-DHP version. I can say that there is a noticeable difference in the X3 when I change the setting from Comfort to Sport mode.

Comfort mode with DHP feels great to me. But note that it is no where near as smooth of a ride as some vehicles, i.e. the Lexus RS350.

RRZ 07-31-2013 07:25 PM

I love DHP. My salesman said only 2% of people get it and it's not really noticeable....of course, he didn't really know what it was and it took him a week of researching it to figure it out. He finally got a car on the lot with it and I tried it and loved it.

The variable steering is very different from normal...you'll find that you often cut corners much, much, much more tightly than ever before (a plus in pulling into parking spots, takes some getting used to avoid taking out the side of your garage or corners in elevated parking garages)...better warn your spouse and kids who don't drive that car regularly!! (I did and my spouse still was oblivious to how the car was turning when pulling into my garage, with me next to her saying "pull past where you normally would to make the turn."

In comfort mode, the car drives nicely, still stable at high speeds, but cushions the bumps in the road (not quite as much as a Lexus, but noticeably softer than in sport mode). Slightly softer than the regular suspension in an X3 without DHP.

In sport mode, everything tightens up. Great for winding roads...even just twists and turns on expressways when you're in traffic and want to keep a tight line at speed. The noticeable advantage is that the car doesn't sway as you come out of the turn, as it would otherwise, with softer suspension active. Feels closer to my Boxster...but clearly the center of gravity in an SUV can't match that in a sports car.

I find myself often changing modes, switching to sport when I want added acceleration or when I'm approaching twists and turns. If you can afford DHP, I'd get it....you probably would like your X3 without DHP in any event, but I suspect it's a feature you'll find yourself using more often than not.

I've gone back to check the steering and there definitely is more "weight" involved in steering when the car is in sport mode.

billyk 08-01-2013 11:50 AM

Quote:

Originally Posted by Liverman (Post 7742949)

GOOD STUFF. May I have more to read? :thumbup:

MetaX 08-01-2013 01:08 PM

Yes that was indeed an interesting read! A bit off-topic but I was quite surprised (and pleased) to read that the electronic parking brake system actually detects if the car starts to roll with the brakes engaged, and if so it will immediately tighten the brakes further and repeats the process up to 3 times if the car is still rolling. I'd say this is probably much safer than manually applying the parking brake but I guess that depends on how much force you typically use to pull on the brake lever.

02420X3 08-01-2013 03:30 PM

Quote:

Originally Posted by billyk (Post 7746642)
GOOD STUFF. May I have more to read? :thumbup:

Check the links in this post:

http://www.bimmerfest.com/forums/sho...d.php?t=709675


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