# Thoughts on 3-series sports suspension



## xspeedy (Apr 10, 2003)

I'm hearing some unusual information in this thread. A vehicle's ride firmness is dictated by springs. The dampers are there to quell the oscillation that comes from springs. It is often said that good springs don't "settle" or break in. So what gives?

As for ride, I'd have to say that the sport suspension is a nice compromise between firm and forgiving. It can get rather stiff on very poor roads, but otherwise, it is very good. I find the ZHP suspension to be very bouncy and hard on rough surfaces. Maybe in CA where there is no such thing as a patched over pothole it is okay, but I don't think the ZHP would be practical in the midwest with potholed roads. If you want handling and don't care too much for ride, then it is awesome. But for me, the ZHP isn't practical for everyday use.


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## WDC330i (Feb 2, 2002)

I have tons of speed bumps in my neighborhood plus torn up roads from water line reconstruction. I also have an '02 330i and a 325xiT. The wagon is way more comfortable over all that crap. In fact, it's way more comfortable on city streets period. BUT, it's also considerably less fun to drive when the road smooths out a bit. The extra height and lack of a sports suspension take most of the joy out of driving. It's pleasurable, comfortable, and sure-footed, but it's not exhilarating.

Best to have both, really. But if you're choosing just one and you love to drive--the sport suspension is the way to go. Just slow down over those speed bumps.

Oh, and I'd add that my 330i has almost 12,000 miles on it and I haven't noticed a softer ride over when it was new. Yet.


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## rumratt (Feb 22, 2003)

TD said:


> If my (now) 71 year old dad can handle an E39 w/sport (and vastly prefer it over the non-sport), I don't really understand how 20-somethings can whine about the E46 sport suspension.


What you're saying is that you can't understand how anyone would have different preferences than you and your father, and that those who do are "whining".

Not to flame, but that that is weak on so many levels (IMO).

Damn. I'm contributing to my own thread hyjak here because I didn't want to get into which choice is right vs wrong.


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## Guest (Aug 30, 2003)

This is a subject very near and dear to me because I can't buy a new BMW because they've all been dumbed down to accomodate people that, by rights, should be buying Lexus ES300s. That's a major problem, IMO.


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## xspeedy (Apr 10, 2003)

TD said:


> This is a subject very near and dear to me because I can't buy a new BMW because they've all been dumbed down to accomodate people that, by rights, should be buying Lexus ES300s. That's a major problem, IMO.


TD, it sounds like you need to remove your springs and dampers and replace them with rocks 

You should look into an S2000, but a 2003 or earlier. The '04s are going to be softer.


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## AF (Dec 21, 2001)

Rumatt, 
When you get your new wheels you might like the ride better, it will definitely feel softer . . . I've noticed that my 330i's ride has been very jolty lately at around 7300 miles . . . I don't notice it as much when I am alone as I do when I have my wife and kids in the car . . . 

I think it is due to the rock hard Contisports . . . they are so damn hard it is probably one of hte worst tires I have ever had on my car . . .

I am definitely getting new tires after the winter . . . I am pretty sure they will be the New Michelin Pilots since I have a love for the old ones, I am thinking the new ones have got to be great !!!

BTW have you checked your tire pressures ?


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## Guest (Aug 30, 2003)

xspeedy said:


> TD, it sounds like you need to remove your springs and dampers and replace them with rocks
> 
> You should look into an S2000, but a 2003 or earlier. The '04s are going to be softer.


 I'm running an E36 M3 with aftermarket Koni shocks and Bridgestone PP S-03 tires and I still think my ride is very comfortable. Granted, it is now exactly to my preference, not too hard, not too soft.


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## rumratt (Feb 22, 2003)

AF330i said:


> When you get your new wheels you might like the ride better,


I don't actually want a softer ride. I'm fine with it. Just a bit suprised at how others described it. I am curious to see what difference the winter wheels/tires make though. It will be a good experiment.



> BTW have you checked your tire pressures ?


Yeah, I've just recently started experimenting but only minimally. I've varried the fronts from 32 to 36 and the rears from 36-40. I haven't been able to do a good job evaluating the changes though. I'm going to drop it back down a bit and go for a ride this weekend.


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## nate (Dec 24, 2001)

The E46 sports suspension is a very good road package, IMO.

Not too soft, not too hard. Extremely composed in most any setting. Understeers at the limit, has plenty of body roll to warn unskilled drivers. Very good, very composed.

I do not find it overly soft in comparison to older or current BMWs. I will disagree with TD. The E39 sport suspension is not firmer or better than the E46 sport. It is just his terribly numb 330i that biases his viewpoint.


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## PhilH (Jun 7, 2002)

TD said:


> Well, if you go back (not even that far) to the E34 5-series you'd see that there was no "sport package". There was one suspension. And it was firmer than the E46 sport suspension.


I strongly disagree. My old E34 525i was a mush-mobile with the stock suspension (and I drove it both when it was new, and also when I bought it at 75k miles). Big body roll and big time ride comfort. There was none of the hobby horsing on the highway that you get with the E46 SP's stiffer suspension, and the E46 handles much flatter.

I _needed_ an aftermarket suspension with the E34 in order to have fun in the corners. In comparison, although my E46 could be a bit stiffer, I'm so happy with the ride/handling compromise that I really might replace my shocks with OEM when the time comes.

However, I agree with you that BMW should offer a tighter SP suspension and leave the current SP as the base suspension.


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## rumratt (Feb 22, 2003)

TD said:


> This is a subject very near and dear to me because I can't buy a new BMW because they've all been dumbed down to accomodate people that, by rights, should be buying Lexus ES300s.


It's a shame (for you) that BMW's are no longer what you want them to be. But that's independent of the fact that you are expecting everyone to feel the same way you do, and criticizing them if they don't.

Are you honestly saying that people who like the handling characteristics of the E46 w/SP should go buy a Lexus ES300, which handles differently? How does that make sense?


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## Mr. The Edge (Dec 19, 2001)

rumatt said:


> It's a shame (for you) that BMW's are no longer what you want them to be. But that's independent of the fact that you are expecting everyone to feel the same way you do, and criticizing them if they don't.
> 
> Are you honestly saying that people who like the handling characteristics of the E46 w/SP should go buy a Lexus ES300, which handles differently? How does that make sense?


I think he's saying they don't "deserve" BMW's because BMW's are supposed to be driver's cars, while Lexuses are for those more concerned with comfortable cars.


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## Guest (Aug 30, 2003)

atyclb said:


> I think he's saying they don't "deserve" BMW's because BMW's are supposed to be driver's cars, while Lexuses are for those more concerned with comfortable cars.


 "Deserve" is too strong.

I am upset that BMW is dilluting their cars so that their cars will appeal to the same folks who like how Lexus ES300s ride.


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## ObD (Dec 29, 2001)

nate328Ci said:


> The E46 sports suspension is a very good road package, IMO.


 :thumbup:


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## dynosor (Jul 15, 2003)

Your butt cannot tell if the loads it feels are from the springs, anti-roll bars or from the dampers because their loads are superimposed. All of these oppose displacement and motion. 

The shocks and suspension pivot points have a lot of friction when new and especially at very low wheel travel velocity, the suspension can almost be stuck because of the static friction. This tends to give a harsh or busy ride over small undulations, but not over bigger ones large enough to break through and un-stick the suspension.

If your tires are soft during this "sticky" phase, the suspension hardly moves, but the car bounces at a much higher frequency on the tire sidewall. This motion is right at the resonant frequency that my head bounces on my neck and gets tiring very quickly. My advice for anyone with a "hard" suspension on a new car is to check the tire pressures, and if not over 34/38 PSI to pump them up to at least that for a while.

My car would ride badly with 32/35 PSI F/R for more than the first 1000 miles, and rode much better with one or two PSI more pressure. Now I can drop it to BMW spec without hurting the ride, but I don't like the lag in steering response, so I keep it to 34/37.5 PSI


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## Nick325xiT 5spd (Dec 24, 2001)

xspeedy said:


> I'm hearing some unusual information in this thread. A vehicle's ride firmness is dictated by springs. The dampers are there to quell the oscillation that comes from springs. It is often said that good springs don't "settle" or break in. So what gives?
> 
> As for ride, I'd have to say that the sport suspension is a nice compromise between firm and forgiving. It can get rather stiff on very poor roads, but otherwise, it is very good. I find the ZHP suspension to be very bouncy and hard on rough surfaces. Maybe in CA where there is no such thing as a patched over pothole it is okay, but I don't think the ZHP would be practical in the midwest with potholed roads. If you want handling and don't care too much for ride, then it is awesome. But for me, the ZHP isn't practical for everyday use.


 Shocks have BOTH compression AND rebound damping. And both of those factors affect ride firmness.


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## joema (Aug 28, 2002)

TD said:


> If my (now) 71 year old dad can handle an E39 w/sport (and vastly prefer it over the non-sport), I don't really understand how 20-somethings can whine about the E46 sport suspension.


 There are several possible explanations:

(1) Unlike most Cadillac-driving 71-yr olds, your dad drove an e34 5-series for years before going to an e39 SP. That would condition him to view that as normal, rather than too harsh. By contrast a 20-something coming off of 5 yrs in a Camry will find their first BMW (say a e46 SP) to be pretty firm by comparison.

(2) Road conditions: this varies hugely from one region to another. An e46 M3 driver in southern California might find his suspension too soft. A 330i non-SP drive in Michigan might find his too firm due to the poor road conditions.

(3) There are variations even within a 330i SP. E.g. some have the optional 18" 255/35 rear tires.

In summary, I'd submit there's a greater chance than you'd think a Camry-driving, naive 1st time BMW buyer living in a potholed section of Michigan will find an e46 with 18" 35-profile tires to be somewhat harsh riding. By contrast the exact same buyer in southern California might not, esp if transitioning from years of a firmer riding car.


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## Matthew330Ci (Sep 9, 2002)

i didn't read the whole thread, but to add to what's being said, being 20-something, i find my 330ci's sport suspension a bit soft. but i still find it a good compromise between comfort and handling. my Civic Si, on the other hand, rode rougher (on the stock suspension) than the 330ci but offered less handling prowess (of course it rode on 195/55/15 tires) but it was much more nimble.


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## joema (Aug 28, 2002)

xspeedy said:


> A vehicle's ride firmness is dictated by springs. The dampers are there to quell the oscillation that comes from springs. It is often said that good springs don't "settle" or break in. So what gives?


As has been mentioned, the view that ride firmness stems exclusively from spring rates is common but incorrect. In addition to the already-mentioned points, the design and dynamic behavior of damper bump stops significantly effects ride quality. These are what prevent your suspension from physically bottoming out, metal-on-metal. They ideally they should be progressive in nature, designed to absorb impact forces gradually (relatively speaking) as suspension travel approaches the limit. The good ones start absorbing force well before the limit, which is different than you might think. A poorly design damper with a simple hunk of rubber as a bump stop will greatly contribute to a rough ride, and often be blamed on spring rates. In fact many factory "sport" springs are only about 25% firmer than stock. From this change alone most people probably wouldn't notice a major worsening in ride harshness.

This is why a high quality, well-engineered sport suspension (whether factory or aftermarket) can improve handling, often without major (or sometimes even significant) degredation in ride quality. Of course as you keep pushing the performance parameter with successively firmer springs, shock rates, higher performance tires, etc. at some point you'll adversely affect ride quality in a major way.

Yet another non-BMW example of how greatly dampers can affect ride quality is the GM "magnetic selective" shocks used on the Corvette. An electromagnetic field varies the fluid consistency within the shock every millisecond based on road conditions. This gives a good ride yet retains good handling. Car & Driver recently had a technical article on this.


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