ZHP Coupe Suspension Maintenance: Lower Control Arm, Brakes and Shocks (Front and Rear)

[AZBP2]

Buon Giorno Famiglia!

The Cali Coupe has been mine for a little over 2 weeks and I am in LOVE!! I was not expecting the ZHP package to make such a huge difference from my last E46 (2004 325i with the sports package). In order to maintain that level of performance while still keeping it stock, I'd like to ask your opinion and perhaps recommendations on which 1. Lower Control Arms, 2. Brakes and 3. Shocks you have used and prefer. I will replace the rear shocks myself (with the help of my brother) and the other items will be handled by the experts. Not ready to take on hardcore DYI yet... Oh, I want to purchase all the parts and have an indy shop here in Houston install them.

After doing quite a bit of research and I leaning towards Sachs OEM shocks. I have read here that the Koni Yellows are awesome and carry a lifetime waranty. The Sachs are at a great price right now...

As far a Lower control arms, I am a bit confused: does the entire arm have to be replaced or is it just the bushing? (theres a big cost difference between the two)...

Finally front and rear brakes. I am leaning towards Akebono pads, but only because that is what the Firestone techs recommended as "BMW Parts"... But again, OEM pads and rotors will work fine for my DD. I just need to be pointed in the right direction.

Thanks in advance for your time.

If its better for me to break up this thread into 3 separate ones (LCA, Shocks and Brakes), let me know and I will. I am still learning the rules/etiquette.

Saluti,

AZ

[BMWCurves]

Brakes
I've only ever had BMW brake pads and Hawk HPS 5.0+ pads. I quite like the Hawk pads due to minimal dust and it has a different but progressive pedal feel/bite. That's not to say the brake pedal feel was bad with the BMW pads, but they're dust monsters for sure. I've heard good things from other members about Akebono, and I might try them out next time around. For rotors the stock rotors are fine. I opted for highly overpriced BMW Performance drilled rotors to shed some unsprung weight and anecdotal improved wet weather performance, but honestly it's personal preference. I'd also suggest stainless steel brake lines at some point (and a clutch line as they all share the same fluid), since the factory hoses will be old and can fail.

Control Arms
I don't know too much about them, but make sure you get the ZHP-specific ones. They're more reinforced than the standard 330i ZSP ones. I believe you have to get the whole arm as the bushing is built in, but someone else would have to confirm.

Suspension
The Sachs shocks/struts don't last particularly long. Mine were completely shot by 50k miles. I and several other members have Koni Sports (yellows) and quite like them. They're more expensive than the Sachs, but they're adjustable and for me 3/4 turn from soft is a great compromise between a comfortable ride and good performance. You might also want to refresh your bushings while you're doing some suspension work. I have a thread/guide on suspension refresh that used mostly OEM parts with a few improvements here and there for an "OEM+" feel. A handful of members said they have found it useful to them when they refreshed their suspension: http://www.zhpmafia.com/forums/showthread.php?17920-BMWCurve-s-Sibling-s-2003-BMW-330Xi-M-Sport-Canadian-Maintenance-Ledger

Hope that helps! Glad you're enjoying your ZHP! As always, post pics and I encourage starting a maintenance/project thread.

[Sreten]

If memory severs me right, that ZHP has less then 50k miles and in that case, I doubt that the control arms are toast.
Inspect the ball joints on them and if everything looks good just go ahead and replace the bushings. ZHP control arms are know to be durable.
Bushings are actually pretty easy to replace, plenty of DIY's out there.

Does the front of the car feels bouncy and unstable? If not and the front struts are not leaking, I wouldn't change them just yet.
Mine were still good when I took them off the car at 98k miles, but then again they were done at 50k miles on BMWCurves's ZHP.

My vote for struts goes towards Koni FSD. They won me over in every way, if you like to ride comfortable and don't want to compromise the sporty handling, I would pick them. Koni yellows are also great choice if you like to have the option to adjust the struts.

If you decide just to change the rear shocks, getting OEM Sachs might not be a bad idea as they are cheaper than Koni and you get to keep the OEM ride quality.
If you don't mind spending the extra money and plan to keep the car for a long time, go with Koni and you won't regret it.



Hope that helps! Glad you're enjoying your ZHP! As always, post pics and I encourage starting a maintenance/project thread.

+1

[AZBP2]

Gents, to both of you, a big Thank you! My car has 55k miles will look into the the parts you suggested. While reading your post, it reminded me that I had a PPI done in LA and it makes no mention of the LCA issues... I will get a 3rd opinion but I have a feeling it may just be the bushings. I have not taken too many photos of her yet but here are a couple I took the day it was delivered.


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[AZBP2]

https://uploads.tapatalk-cdn.com/20170427/4d259889a2150b89aa6f5ed1684a4958.jpghttps://uploads.tapatalk-cdn.com/20170427/5b22db60bc8358d9cff18ce6e6a58c9a.jpg


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[AZBP2]

https://uploads.tapatalk-cdn.com/20170427/6ed364693122546895d52078a9382a91.jpg


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[AZBP2]

She's a little dusty with the Texas trees pollinating but she'll definitely look sharper next time. Thanks again


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[BMWCurves]

Looks good!

Your coupe reminds me how I found mine when I bought it, essentially stock.

[AZBP2]

Yep, the lady who owned it in Burbank, CA works for the school district and had a commute of less than 15 miles daily. Original owner, never abused and she sincerely loved this car. I could see that when I met her and her son during my test drive. The car came with all services (or as many services as 55k mikes entail). All documents and manuals. Now I know what you all mean when you say the car should smell like crayons :). The car is in great shape and I just want to take care of the suspension work for long term piece of mind as it is certainly something we all have to do down the road (pun not intended)


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[AZBP2]

Peace**


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[Sreten]

Easiest way to tell if the FCAB are shot, drive at low speed and stab the brake. You will feel the wheels move if they are bad, causes the steering wheel to jump left and right.

Nice car!

[AZBP2]

I'll try that and let you know. Thanks for the insights


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[AZBP2]

[QUOTE=Sreten;529190]If memory severs me right, that ZHP has less then 50k miles and in that case, I doubt that the control arms are toast.
Inspect the ball joints on them and if everything looks good just go ahead and replace the bushings. ZHP control arms are know to be durable.
Bushings are actually pretty easy to replace, plenty of DIY's out there.

Does the front of the car feels bouncy and unstable? If not and the front struts are not leaking, I wouldn't change them just yet.
Mine were still good when I took them off the car at 98k miles, but then again they were done at 50k miles on BMWCurves's ZHP.

My vote for struts goes towards Koni FSD. They won me over in every way, if you like to ride comfortable and don't want to compromise the sporty handling, I would pick them. Koni yellows are also great choice if you like to have the option to adjust the struts.

If you decide just to change the rear shocks, getting OEM Sachs might not be a bad idea as they are cheaper than Koni and you get to keep the OEM ride quality.
If you don't mind spending the extra money and plan to keep the car for a long time, go with Koni and you won't regret it.



+1
Quick Update: I got a 3rd opinion on the suspension work and found out that the LCAs are fine. You were right and I just need to replace the bushings. Shocks are also fine; not leaking. So keeping them for a while longer and saving $ for something else.

Thanks for the advice. !!



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[Sreten]

Glad it worked out. Enjoy in your ZHP. :thumbup

[BMWCurves]

Quick Update: I got a 3rd opinion on the suspension work and found out that the LCAs are fine. You were right and I just need to replace the bushings. Shocks are also fine; not leaking. So keeping them for a while longer and saving $ for something else.

Thanks for the advice. !!



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Did you actually remove the struts/shocks? When I replaced mine, they had no visible signs of leakage or anything, but they were 100% dead and in need of replacement because they had zero rebound. An easy way to test is to check the rears since you don't have to take apart the assembly, just remove it from the rear suspension. Compress them and see if they rebound quickly.

[AZBP2]

Had it done by BMW and also did the rebound test. They rebound quickly and straight up. I'll keep an eye on them and replace them same time as the rear brakes .


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[AZBP2]

In the meantime, what symptoms should I notice when they start to go bad and need replacement? As far as ride quality.


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[BMWCurves]

Had it done by BMW and also did the rebound test. They rebound quickly and straight up. I'll keep an eye on them and replace them same time as the rear brakes.


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Sounds good. If BMW say they're okay then they should be fine. BMW dealerships love to suggest expensive replacements, so if they don't even pretend for there to be any issues, then they must be in decent shape.


In the meantime, what symptoms should I notice when they start to go bad and need replacement? As far as ride quality.


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Mine were already shot by the time I got them, but what I noticed a lot was that the suspension was quite bad at absorbing small bumps. It felt like the first 1-2" of travel weren't being properly absorbed. As far as performance goes, I noticed that the back was easily unsettled over uneven roads in turns. New shocks/struts and other suspension components made the car feel a lot more planted in the bends during more aggressive driving.

[AZBP2]

Got it. I'll be on the lookout for those symptoms. Thanks again.


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[san]

Sounds good. If BMW say they're okay then they should be fine. BMW dealerships love to suggest expensive replacements, so if they don't even pretend for there to be any issues, then they must be in decent shape.



Mine were already shot by the time I got them, but what I noticed a lot was that the suspension was quite bad at absorbing small bumps. It felt like the first 1-2" of travel weren't being properly absorbed. As far as performance goes, I noticed that the back was easily unsettled over uneven roads in turns. New shocks/struts and other suspension components made the car feel a lot more planted in the bends during more aggressive driving.

Did you replace the rtabs on your car?


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[BMWCurves]

I did. I used Z4M RTABs with Vorshlag limiters. If I had to do it again I'd probably go Peter's route and use Bimmerworld sealed spherical RTABs for better articulation. Then again, it rides/handles great as is and I doubt I'd really notice the difference.

[AZBP2]

[QUOTE=Sreten;529190]If memory severs me right, that ZHP has less then 50k miles and in that case, I doubt that the control arms are toast.
Inspect the ball joints on them and if everything looks good just go ahead and replace the bushings. ZHP control arms are know to be durable.
Bushings are actually pretty easy to replace, plenty of DIY's out there.

Does the front of the car feels bouncy and unstable? If not and the front struts are not leaking, I wouldn't change them just yet.
Mine were still good when I took them off the car at 98k miles, but then again they were done at 50k miles on BMWCurves's ZHP.

Sir,
You were correct on replacing the bushings! thanks!!


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[AZBP2]

Sounds good. If BMW say they're okay then they should be fine. BMW dealerships love to suggest expensive replacements, so if they don't even pretend for there to be any issues, then they must be in decent shape.



Mine were already shot by the time I got them, but what I noticed a lot was that the suspension was quite bad at absorbing small bumps. It felt like the first 1-2" of travel weren't being properly absorbed. As far as performance goes, I noticed that the back was easily unsettled over uneven roads in turns. New shocks/struts and other suspension components made the car feel a lot more planted in the bends during more aggressive driving.

Sir,

Re: I noticed that the back was easily unsettled over uneven roads in turns.

You were 100% correct: The rear shocks are starting to go and a new ones are going in next week.

I had not driven the car that much since I got it (too much work travel) but when I did I notice the back was " unsettled" around turns.

Thanks again!



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[papa_g]

I remember doing the rear shocks. They were so easy, I did the left side one night before bed, and the right side the following morning while I was in a hurry waiting for my friend to come pick me up. I followed this video:
https://www.youtube.com/watch?v=x_1zTqHtzI8
the dude is hilarious and is pretty wasted when he does his DIYs
That insulating material that he threw out; mine was brittle but still holding together in one piece. I jsut cut away enough to reach the center nut on the shock tower, and the shock dropped right out. Then once I reinstalled the shock, I put a piece of adhesive sound insulation over the hole I cut out, because why not.

If filling your own gas is a 1 in difficulty (5 if you live in Oregon), I would rate this a 3.

[BMWCurves]

If filling your own gas is a 1 in difficulty (5 if you live in Oregon), I would rate this a 3.

HEY! Just because I don’t pump my own gas or sometimes I forget you shouldn’t stick a fork in the power outlet doesn’t make me dumb!


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[papa_g]

HEY! Just because I don’t pump my own gas or sometimes I forget you shouldn’t stick a fork in the power outlet doesn’t make me dumb!

Haha hey man I don't judge.
On a serious note though, is Oregon passing a new law to allow people to pump their own gas? I heard this recently.

[BMWCurves]

Haha hey man I don't judge.
On a serious note though, is Oregon passing a new law to allow people to pump their own gas? I heard this recently.

Yeah, some rural counties in Oregon can pump their gas now. "Pump your own gas"...it's like the country is going to the dogs