[exon]

Originally Posted by halfmoonclip

Yep, I've been carpetbombed with responses, and they are appreciated. The PP who noted that I likely can't test hop such a car is likely dead nuts on....as I said, our salesman had never seen nor sold one.
So we'll hold on that for now, and it does simplify things a bit. BMW's assortment of packages can be overwhelming.
We are torn among an Audi Allroad (we currently have an Avant), a Q5 or an X3. I love my X1, and did test hop a new X1 (I'll keep the one I have, thank you!), but the new model does offer more space. The car will be mostly my bride's tho' we use her's as the tripmoblile.
I'll let you know how it shakes out; thanks for the comebacks.
Moon

Just to make your decision harder:

Q5 is due for re-design in this year, X3 in 2016/2017. And Mercedes GLC is just out (fantastic interior). Jaguar F-Pace will be out in Spring (looks promising based on specs)..

[Polo08816]

Originally Posted by exon

Changing the fluid viscosity isn't the only way to change damping, you can change the valve sizing quite quickly too

here, let me rephrase the sentence for you: (j/k)

"Again, if M Performance Suspension kit (static suspension) is so great, why does BMW even bother to offer DHP for the F30 3 Series RWD sedan. "

Since spring, damping and bushing works as a system, I prefer a holistic view. Soft spring is not necessarily bad, high spring rate doesn't guarantee awesome. Viewing the components in such isolation is overly simplistic IMHO.

Also DHP, high-spring rate, good tires are not exclusive of each other, so I see the "DHP vs firm spring", or "DHP vs tires" as apple to orange comparisons.

But, I think both of us understands in detail what suspensions we are getting into. We may have to agree to disagree on this topic, given our very different usage of vehicles, value perspective and very different vehicles.

As far as valves adapting quickly, possible but not prevalent in practice. Precision control of valves at those speeds is going to be pretty complex.

I think the vast majority on the F30 forums see the suspension hiearchy for RWD (in RWD configuration, DHP and Sport suspension use the same springs which have a higher spring rate than xDrive) as follows:

Sport suspension <= DHP < M Performance Suspension

There's debate on whether the DHP or Sport suspension are better. There's generally a consensus that he M Performance Suspension (matched springs/shocks) combo is superior to either.

Also, yes, I agree that a high spring rate doesn't guarantee success. You can go to the Suspension F30 sub-forum and see all the epic fail of people just installing lowering springs with OE shocks (and even with Bilstein HD/Sport shocks I might add) and busting their top hat.

At the end of the day, I'm convinced that any OEM solution (DHP or not) and any premium coilover solution (Bilstein PSS10, KW V2+, AST, Ohlins, etc.) will far surpass some driveway mechanic with a psychology degree mixing and matching springs/shocks. After all, BMW doesn't hire engineers to spend hundreds of thousands of man hours to design, simulate, test, etc. all this stuff just for lulz.

[exon]

Originally Posted by Polo08816

I think the vast majority on the F30 forums see the suspension hiearchy for RWD (in RWD configuration, DHP and Sport suspension use the same springs which have a higher spring rate than xDrive) as follows:

Sport suspension <= DHP < M Performance Suspension

Just to keep in mind the X3 crowd may put higher value on smooth/quiet ride (at least i am) and less so on the handling or max grip, so different audience and value perspective here.

BTW, I suspect the spring rates relative to vehicle weight is higher on the X3 than F30 to keep the high center of gravity in check. So we may want to go soft while F30 owners may prefer to go stiff.

Originally Posted by Polo08816

At the end of the day, I'm convinced that any OEM solution (DHP or not) and any premium coilover solution (Bilstein PSS10, KW V2+, AST, Ohlins, etc.) will far surpass some driveway mechanic with a psychology degree mixing and matching springs/shocks. After all, BMW doesn't hire engineers to spend hundreds of thousands of man hours to design, simulate, test, etc. all this stuff just for lulz.

Totally agree with you here. Suspension tuning has so many interacting variables, even with modern day computing/simulation it is still a tough mix of art and science... In my book the top players are still BMW and Honda (i don't have much experience with Audi though).

[clivem2]

I've had European real MSport suspension and DHP versions. In terms of handling they are equivalent. In terms of comfort they are miles apart. DHP every time.

[Polo08816]

Originally Posted by clivem2

I've had European real MSport suspension and DHP versions. In terms of handling they are equivalent. In terms of comfort they are miles apart. DHP every time.

All else equal, that's a fair assessment.

However, a laughable situation is someone who purchases 20" wheels, complains about ride quality and harshness, and requires DHP to soften up the ride.

In the US, there is nothing "uncomfortable" about a base suspension X3 with 18" wheel combo. The suspension is rather soft to begin with.

At the end of the day, will DHP help you drive on 2 wheels better?

[DocWeatherington]

Originally Posted by Polo08816

It's not cheap. Have you looked at replacement part cost? On my 335i M Sport RWD, it's about 2-3x the replacement cost of a Sport strut.



DHP isn't going to fix not having enough of a spring rate.

Agree, but the OP might like it as is