ZHP ride and handling characteristics???

[Bludsport]

I just heard back from the transportation outfit that's shipping my car that it should arrive on the 16th. When it does, this will be the first time I've ever driven a ZHP. I owned a 2009 M3 convertible for about 3 years and found it to be slightly harsh, especially while driving on crappy city streets or uneven pavement. Great on the track, but the chassis stiffness combined with the low profile 19" tires would get tiresome on occasion.

On a scale of 1 to 10, with 1 being the softest, how would you guys describe the ride and handling characteristics of the ZHP compared to the E93 M3?

The '06 ZHP I just bought was a former CPO vehicle and has about 69K miles on the odometer. The dealer that sold it to me drove it to the local BMW dealership to correct the airbag recall and have a full inspection performed. The car checked out fine by BMW, but after he had driven it, he told me that he could feel a small amount of play in the steering and that it would be a good idea to replace the control arm bushings when it arrives. I'll get my local dealership to handle it, but while it's there, are there any other little rubber bits like motor & transmission mounts, tie rod ends and anti roll bar bushings that should be replaced at the same time?

Thanks!

[BMWCurves]

I am impressed you were willing to buy a car sight unseen without having driven it. I could never do that, at least not without having driven a similar car.

At any rate, I have never driven or ridden in an E9x M3 so it's tough to me to compare. However, I can describe the ZHP a bit. In the stock setting, it is very good as a daily driver. It's comfortable and compliant and absorbs rough roads relatively well. However this is dependent on your suspension's health. My 2005 330Ci with only 49k miles had completely worn factory shocks and the ride was a bit harsh and struggled to absorb small bumps well. As a result, I did a suspension refresh about a year and a half ago and it definitely improved the ride comfort. It should be noted that ride comfort is probably a bit by the factory style 135 wheels because they are large (18" diameter), come with low profile tires, and are heavy (27-28 lbs a piece i.e. added unsprung weight). All of these things stack up to marginal decrease in ride comfort. That said, they look great and are a defining part of the ZHP.

As for performance it is an decent suspension setup and great for its age. Again, it errs on the side of a daily driver, but it is still plenty competent in the corners. The car willing to change direction well, has great feedback, and has decent grip. Compared to the E9x M3, it'll probably roll more just due to less torsional rigidity of the chassis, but you can remedy some of that with bigger sway bars. When I refreshed my suspension I opted to go for Koni Sports which are adjustable shocks. In their current setting (3/4 turn from soft) they have good ride comfort with better performance. The other thing I did to improve handling was to get a different set of wheels. I opted for a square setup of 17x8.5" ET40 APEX ARC8 wheels which shed about 11 lbs per corner and had the added benefit of taller side walls that improved ride comfort. The car now feels more planted, eager, and capable in the corners than before. One of my favorite mods/upgrades.

As I said before, the ZHP is a great daily driver and very capable when you cane it in the back roads. If the car you bought was dealer maintained I would be very surprised if any suspension components were replaced, meaning the vast majority are 11+ years old now. Your car will be due for suspension refresh for bushings, most likely shocks, and possibly things like tie rods, end links, etc. I would have it taken to an independent BMW specialty shop if you're not doing your own maintenance, you can save some money there over the dealership. If you don't know of any independent BMW mechanics in your area, try looking through http://bimmershops.com/ first, they're a good quick and dirty resource for that.

If you're contemplating what parts you may need for a partial suspension refresh, you can take a look at my refresh thread I have when I did my car at 50k miles. The first post has the parts I used for a relatively factory refresh with a few improvements (sort of an OEM+), plus a list of additional parts you might consider: http://www.zhpmafia.com/forums/showthread.php?16182-Help-with-Suspension-Refresh-at-50k-miles-10-years

If you are thinking about wheel size as well, you can take a look at my thread discussing the ARC8 when I was trying to decide what to do, plus a cool article by Road and Track on acceleration improvements when getting lighter wheels: http://www.zhpmafia.com/forums/showthread.php?16922-Apex-ARC8-17-quot-vs-18-quot-Offset-and-Tire-Size-Questions

Good luck, post pics when the car arrives!

[Vas]

You are going to like it but it's slow.

Look into improving the suspension since most components are going to be worn out.

[Bludsport]

Don't be impressed. I've done this before and the last time didn't work out so well. I bought a 1964 Triumph TR-4 in 2008 that was the subject of a "frame-off" restoration. The car looked fantastic, but one day while conering a little hard, it felt like the rear end was going to fall off. An inspection with an ice pick relvealed that the frame was completely rusted out on the inside and had been covered with Bondo and painted over. Fingers crossed on the XHP. The funny, if not ironic part, is that both cars came from the San Francisco area.

I do plan on replacing the wheels and tires when soon and have been looking at the Apex wheels as well. The square set up makes sense to me and I'll most likely do the same.

Why did you opt for the 17" wheels instead of the 18"?

Thanks for the great input and advice and I'll take a look at your mod list.

[BMWM3186]

I think my Zhp with the stock suspension is fairly harsh but not unbearable. My friends e36 with Bilstein tourings, and g37 definitely soak up bumps better but I guess those cars aren't as geared towards performance driving as much.

[BMWCurves]

For a handful of reasons.

17" wheels were a pound lighter than the equivalent 18" in the same width
Tires would be slightly cheaper in 17"
Additional sidewall height would ideally provide an improvement in ride quality.

[zhp05jb]

Having driven mine for the past 15K miles or so (currently @90k miles) I always felt that stock ZHP suspension is on the soft/comfortable side. This is comparing it to my old cars: S2000 and Integra Type R.

[slater]

Having driven mine for the past 15K miles or so (currently @90k miles) I always felt that stock ZHP suspension is on the soft/comfortable side. This is comparing it to my old cars: S2000 and Integra Type R.

agreed, it is definitely a little softer than an ITR. i had one new in 2001. that thing was just perfect right out of the box... the stock suspension was fantastic.

[az3579]

I think my Zhp with the stock suspension is fairly harsh but not unbearable. My friends e36 with Bilstein tourings, and g37 definitely soak up bumps better but I guess those cars aren't as geared towards performance driving as much.

Perhaps you need a suspension refresh (new shocks, perhaps). The stock ZHP suspension is typically far from harsh.
My car is still comfortable with Bilstein PSS10's, and those are far firmer than a stock ZHP suspension.

[BMWM3186]

Perhaps you need a suspension refresh (new shocks, perhaps). The stock ZHP suspension is typically far from harsh.
My car is still comfortable with Bilstein PSS10's, and those are far firmer than a stock ZHP suspension.
Is there a way of knowing? I don't feel as if it bounces when I push on it. I can also hear the rear shocks with the windows down when I hit a bump is that normal? Also, I feel like I'm going to break something when I go over those bridges on the interstate at 80+ But Im used to SUVs so I don't have a basis for what it's supposed to feel like.

[az3579]

Is there a way of knowing? I don't feel as if it bounces when I push on it. I can also hear the rear shocks with the windows down when I hit a bump is that normal? Also, I feel like I'm going to break something when I go over those bridges on the interstate at 80+ But Im used to SUVs so I don't have a basis for what it's supposed to feel like.

When one of my front shocks died, it sounded like every little bump I hit was a crater. The car never got bouncy.
I think it's normal to hear a tiny bit of shock noise as it dampens the shock, but it's not supposed to be audible enough to hear it with the windows down while driving at speed.

[PetesZ]

If the OEM shocks have over 50K on them - they are toast.

Depends on what you hear from the rear shocks (should not hear anything) - would make a bet that something is broken - shock/bushing. Their are know issues with "noise" from the rear deck (ie rear deck rattle)

The Daughters 05 coupe is silent (event with the 104K OEM shocks) - even more silent with the new Bileistin 06 shocks....

[BMWM3186]

If the OEM shocks have over 50K on them - they are toast.

Depends on what you hear from the rear shocks (should not hear anything) - would make a bet that something is broken - shock/bushing. Their are know issues with "noise" from the rear deck (ie rear deck rattle)

The Daughters 05 coupe is silent (event with the 104K OEM shocks) - even more silent with the new Bileistin 06 shocks....
Almost sounds like air when I come off a bump and they rebound

[PetesZ]

OK - that's better than a "clump".

The 100K OEM shocks were dead in that they had no negative rebound (would not extend) -

It is about the easiest job to do - (on par with changing the oil) - took about 30mins for me to do both.

[BMWCurves]

If you are on your stock shocks, I would say just remove one of the rear shocks (relatively easy to do) and compress it. If they don't rebound well, and I mean really don't rebound (takes 40+ seconds), then they're due for replacement. On miles and age alone I'd think you're due, but physically checking one of the shocks is one way to be sure.

[Bludsport]

After driving my car for a while, I feel the suspension is a bit soft, not totally "mushy", but a bit soft for my tastes. The front end clunking while braking and accelerating is aggravating, so this was my first priority. ECS Tuning put together a "refresh" kit for my front end consisting of the following:

1. 2 Bilstein ZHP lower control arms
2. Left and right Sway bar links
3. Left and right tie rod assembly
4. Left and right dust boots

I also ordered 2 Rogue aluminum wrapped FCAB's instead of going with the factory rubber.

I'm having everything installed later this week. Next up will be new shocks, or maybe coilovers and a full refresh for the rear end.
I don't want to lower the car mainly because of clearance issues with the roads around here, so I'm not too sure if the coilovers would be worth it or any better than a set of Koni sport shocks like you used. I'm thinking of using all Rogue bushings and shock mounts as well as their articulating spring perches for the rear refresh. I'll also most likely replace some other stuff such as sway bar bushings.

If I go with all Rogue parts for the rear end, do you think there would be a noticeable increase in noise and vibration?

[holyc0w]

I think you would like the Koni sports.

[Dave1027]

I also ordered 2 Rogue aluminum wrapped FCAB's instead of going with the factory rubber.

Yeah the clunking while braking is likely fcabs but those aluminum Rogues are meant for the track. My opinion is they go much further in the stiffness than is necessary. I'm running Meyle's which are solid rubber not oil filled like the stock ones. But who knows? Suspension tastes are very subjective. I thought my stock suspension was too firm when I first got the car.

[Bludsport]

You're right, very subjective. My last car was an '09 M3, and that car was a little hard on your ass after a few hundred miles. Forget about it on crappy city streets. For me, my ZHP feels a little mushy and other than the clunking aggravation, it's the main reason for the refresh. I thought the same thing about the Rogue bushings, probably way too stiff for a street car. Then I talked to the guys at Rogue about them and they told me they have two different inserts for the aluminum housing, one is for racing, the other for street use. They claimed that any additional harshness, vibration or noise should not be noticeable, so I went ahead and got them. I'll let you know how they feel after I have everything installed in a week or so.