ZPOST
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   ZPOST > BMW Z4 Technical Talk > Suspension and Braking Chat
  TireRack

SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS!
Post Reply
 
Thread Tools Search this Thread
      03-02-2020, 03:23 PM   #1
ryank382
First Lieutenant
ryank382's Avatar
102
Rep
343
Posts

Drives: E92 M3, Z4 M Roadster
Join Date: Aug 2011
Location: New Jersey

iTrader: (0)

OEM Front end too soft and loose?

Hello all,

I've done a fair bit of reading and searching and even learned some new things from the many members here who know significantly more than me about suspension components. I'm on stock suspension and i'm not sure exactly how to describe it but i'd like to tighten up my front end so to speak. Not sure if its because the front end feels softer then the rear but I feel as if the steering can be more precise, and front springs could be stiffer. I don't feel any significant body roll but I don't feel super confident about how loose and floaty the front end feels especially at highway speeds.

For example on my F80 m3 with KW v3s the cars handling feels like "its on rails" so to speak. Very precise steering and I can place the car perfectly. The car feels very confident and not floaty at all. I know exactly where the cars going with any steering input. Z4m compared to that is less accurate. Obviously there will be a difference but it feels drastic to me. Maybe i've just gotten used to the precision of electric steering on the f80? not sure. I don't think that there is anything mechanically wrong or worn out and needs maintenance. I just feel like there is a vast amount of improvement to be done about this from factory

Car only has 36k miles and bushings are all good. Was wondering if anyone else feels the same way as me and what the first step to take would be?

I feel like coils would probably be the most obvious option and make the biggest difference while also helping with ride comfort as the oem suspension feels very harsh on any road imperfections

I've been reading about LCABs and such but i'm not that familiar with that stuff regarding an improvement you can feel. Never upgraded bushings before.

Trying to go the more affordable route as i'm in the process of selling the f80 to buy and heavily mod an e92 m3.

TIA
Appreciate 0
      03-03-2020, 11:07 AM   #2
The HACK
Midlife Crises Racing Silent but Deadly Class
The HACK's Avatar
1817
Rep
5,337
Posts

Drives: 2006 MZ4C, 2021 Tesla Model 3
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

iTrader: (1)

This has been the complete opposite of my experience. The front end on the Z4 M is about as tight as you'd ever want it to be compared to any other "modern" BMWs made after 2000, and anything after 2010 is only getting progressively worse.

It really comes down to what one describes as "tight" or "loose" or "precise." I once had a friend drive my Z4 M Coupe, as we met up and had a short drive up a local mountain road on a Saturday morning. He drives an F30 340i daily and was surprised at how quick the steering rack is, and struggled with placing MY car around some of the corners on said mountain road because every hundredth of a degree of movement on the steering wheel translates to action on the front wheels. It is by far one of the shortest lock to lock ratios BMW has produced, and also one of the tightest rack BMW has produced with virtually zero "dead" on center feel.

I've driven a WIDE variety of BMWs in the last 20 years as part of my weekend duties as an instructor for BMW CCA's Pacific Region HPDEs, and I wouldn't call any of the BMWs produced after 2010 with electronic steering "precise." Especially after having driven daily the Servotronic hydraulic steering. Yes, call me "boomer" all you want, but you really need to experience the Servotronic hydraulic power steering. It is one of the best implementation of power steering in the world, and for a long time, considered on par with the likes of SUPER CARS from Ferrari and Lambo. The E36 M3 rack, which the Z4 M rack is based on, was at one point considered the best steering rack in the world back in the late 90s, and believe you me, BMW steering rack feel has been on a very steady downhill ever since.

Now. If you were to say the front end of the Z4 M "pushes" with stock alignment on stock width tires, I'd probably agree. From the factory the Z4 M's geometry makes the front end grip limited, with a -0.7º and moderate toe-in to alleviate the quick rack and massive caster angle. On purely stock settings, the car will tend to push into a turn, which is exacerbated by the quick and precise steering, as the natural tendency to feed in more steering, even ever so slightly at just past corner entry, results in further loss of traction up front because small movements of the steering results in larger than relative movement of the wheels and tires. The Z4 M rewards precision and smoothness, and REQUIRES driver input to be accurate as intended. It doesn't bother to cover up your mistakes, it announces it to the world you'd done f**ked up on turn-in. Unlike newer BMWs where they make every attempt at hiding your mistakes and making you feel like a hero, the Z4 M rewards you for actually being a good driver.

Which isn't to say maybe there is something wrong with your Z4 M. But, my experience on this matter differ from yours. The Z4 M front end is a gem, and it's one of the best BMW has produced during a period when BMW had perfected the front end MacPherson Strut design.
__________________
Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
Appreciate 2
longress104.50
Vanne1593.00
      03-03-2020, 01:16 PM   #3
ryank382
First Lieutenant
ryank382's Avatar
102
Rep
343
Posts

Drives: E92 M3, Z4 M Roadster
Join Date: Aug 2011
Location: New Jersey

iTrader: (0)

Quote:
Originally Posted by The HACK View Post
This has been the complete opposite of my experience. The front end on the Z4 M is about as tight as you'd ever want it to be compared to any other "modern" BMWs made after 2000, and anything after 2010 is only getting progressively worse.

It really comes down to what one describes as "tight" or "loose" or "precise." I once had a friend drive my Z4 M Coupe, as we met up and had a short drive up a local mountain road on a Saturday morning. He drives an F30 340i daily and was surprised at how quick the steering rack is, and struggled with placing MY car around some of the corners on said mountain road because every hundredth of a degree of movement on the steering wheel translates to action on the front wheels. It is by far one of the shortest lock to lock ratios BMW has produced, and also one of the tightest rack BMW has produced with virtually zero "dead" on center feel.

I've driven a WIDE variety of BMWs in the last 20 years as part of my weekend duties as an instructor for BMW CCA's Pacific Region HPDEs, and I wouldn't call any of the BMWs produced after 2010 with electronic steering "precise." Especially after having driven daily the Servotronic hydraulic steering. Yes, call me "boomer" all you want, but you really need to experience the Servotronic hydraulic power steering. It is one of the best implementation of power steering in the world, and for a long time, considered on par with the likes of SUPER CARS from Ferrari and Lambo. The E36 M3 rack, which the Z4 M rack is based on, was at one point considered the best steering rack in the world back in the late 90s, and believe you me, BMW steering rack feel has been on a very steady downhill ever since.

Now. If you were to say the front end of the Z4 M "pushes" with stock alignment on stock width tires, I'd probably agree. From the factory the Z4 M's geometry makes the front end grip limited, with a -0.7º and moderate toe-in to alleviate the quick rack and massive caster angle. On purely stock settings, the car will tend to push into a turn, which is exacerbated by the quick and precise steering, as the natural tendency to feed in more steering, even ever so slightly at just past corner entry, results in further loss of traction up front because small movements of the steering results in larger than relative movement of the wheels and tires. The Z4 M rewards precision and smoothness, and REQUIRES driver input to be accurate as intended. It doesn't bother to cover up your mistakes, it announces it to the world you'd done f**ked up on turn-in. Unlike newer BMWs where they make every attempt at hiding your mistakes and making you feel like a hero, the Z4 M rewards you for actually being a good driver.

Which isn't to say maybe there is something wrong with your Z4 M. But, my experience on this matter differ from yours. The Z4 M front end is a gem, and it's one of the best BMW has produced during a period when BMW had perfected the front end MacPherson Strut design.
Interesting. Well first off thanks for the detailed response. I agree with everything you said about the steering feel and feedback but i have the roadster and AFAIK we have different racks, yours being quicker. I do not mean the car pushes at all or has a front end traction issue because it doesnt. and the only modern day bmw that i would call precise is my f80. I feel like I may be having trouble trying to get across what im trying to describe. What im trying to say is in a hypothetical scenario if I were a teenager hooligan trying to weave around traffic at highway speeds, I would feel significantly more confident doing it in my f80 compared to the z4m. The front just doesnt feel planted and therefore when im changing direction I feel like I do not 100% trust where the car is going to go as much as i trust my f80 for example.

I do not want to over-exaggerate what I'm feeling. its not so bad that I hate the car or anything its just something id like to improve because I think theres a lot of room for improvement. Maybe something is off in my car not sure. But ive been driving cars on KW coils for the last approx 8-9 years so maybe I've just gotten used to that?

I recall reading about other people who thought factory suspension front is way too soft in comparison to the rear but not sure
Appreciate 0
      03-04-2020, 01:24 AM   #4
gnx
Όλα ρόδες
gnx's Avatar
752
Rep
555
Posts

Drives: BMW
Join Date: May 2008
Location: Athens, Greece

iTrader: (0)

Garage List
Further to The HACK's remarks, I can't stress enough how important it is to change front axle geometry.

I remember before installing my Vorschlag camber plates in 2012 how the car did push on OEM Contis with front camber set at -0.5º from the factory.

Post camber plate installation, I have never driven any bmw with such a precise front end, bmw m2C included.
Appreciate 0
      03-05-2020, 03:20 PM   #5
Jumbosock
Captain
Jumbosock's Avatar
75
Rep
987
Posts

Drives: 2007 M coupe
Join Date: Apr 2011
Location: San Diego

iTrader: (0)

I installed KWV3 because I hated the feel of the suspension. It was oddly mushy and unpredictable. I am at stock height with the KWV3 because I did not want to go any lower. I did have to add a KW spring spacer up front (I think 20mm) to retain OEM height. The car instantly felt much better than stock and much more predictable.
__________________

CSL headers*Euro cats*Arqray exhaust*DKF hangers*Evolve Tune*Genuine CSL rims*10mm Macht Schnell front spacers*modified Hamann bumper*Tekarbon 2X2 CF spoiler*Turner CF grills*AS SSK*KWV3*OEM Strut bar*Rogue RSM*Polyurethane anti-roll bar bushings*Deka ETX30L battery*Nav Video module*front & rear cameras*Ipod module*stubby antenna*R-Dash LED license lights*LED Ziza interior lights
Appreciate 0
      03-05-2020, 06:57 PM   #6
ryank382
First Lieutenant
ryank382's Avatar
102
Rep
343
Posts

Drives: E92 M3, Z4 M Roadster
Join Date: Aug 2011
Location: New Jersey

iTrader: (0)

Quote:
Originally Posted by Jumbosock View Post
I installed KWV3 because I hated the feel of the suspension. It was oddly mushy and unpredictable. I am at stock height with the KWV3 because I did not want to go any lower. I did have to add a KW spring spacer up front (I think 20mm) to retain OEM height. The car instantly felt much better than stock and much more predictable.
Quote:
Originally Posted by gnx View Post
Further to The HACK's remarks, I can't stress enough how important it is to change front axle geometry.

I remember before installing my Vorschlag camber plates in 2012 how the car did push on OEM Contis with front camber set at -0.5º from the factory.

Post camber plate installation, I have never driven any bmw with such a precise front end, bmw m2C included.
Yes I'm def thinking about adding some camber up front thank you. Never played around with that before curious how much of a difference it'll make in "spirited" driving lol

Quote:
Originally Posted by Jumbosock View Post
I installed KWV3 because I hated the feel of the suspension. It was oddly mushy and unpredictable. I am at stock height with the KWV3 because I did not want to go any lower. I did have to add a KW spring spacer up front (I think 20mm) to retain OEM height. The car instantly felt much better than stock and much more predictable.
Mushy sounds like how I feel. Looks like I gotta grab some coils. How's convenient is the adjustability with the v3s? can you easily access the top of the rear struts? I think I remember reading somewhere that people were cutting holes in their trunks to get to it which I honestly wouldn't mind doing
Appreciate 0
      03-11-2020, 01:43 PM   #7
The HACK
Midlife Crises Racing Silent but Deadly Class
The HACK's Avatar
1817
Rep
5,337
Posts

Drives: 2006 MZ4C, 2021 Tesla Model 3
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

iTrader: (1)

Also, don't forget, just because the mileage is low doesn't mean the bushings aren't shot. They're rubber. They age out. Even the youngest OEM bushings are at least 12 years old. I would change the front end bushings regardless of the mile at this point of life.
__________________
Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
Appreciate 0
      03-11-2020, 02:25 PM   #8
ryank382
First Lieutenant
ryank382's Avatar
102
Rep
343
Posts

Drives: E92 M3, Z4 M Roadster
Join Date: Aug 2011
Location: New Jersey

iTrader: (0)

Quote:
Originally Posted by The HACK View Post
Also, don't forget, just because the mileage is low doesn't mean the bushings aren't shot. They're rubber. They age out. Even the youngest OEM bushings are at least 12 years old. I would change the front end bushings regardless of the mile at this point of life.
I considered that but I had my shop look over all the bushings and they said they're all fine. I was afraid I wouldn't know what to look for as I'm not too too handy but will do the due diligence myself soon and figure it out. Thank you for the advice
Appreciate 0
      03-12-2020, 10:48 AM   #9
wss4
Private First Class
35
Rep
159
Posts

Drives: 2008 Z4 M Coupe
Join Date: Mar 2011
Location: San Diego

iTrader: (3)

Struts likely worn out. New aftermarket suspension and alignment should address what you're feeling.
Appreciate 0
      03-16-2020, 12:52 PM   #10
Yapakanichi
Monkey Marshall
Yapakanichi's Avatar
621
Rep
218
Posts

Drives: 2005 Z4 3.0i
Join Date: Dec 2016
Location: FL

iTrader: (0)

Check your inner/outer tie rods and ball joints. Just replace them, it's cheap. Also get polyurethane bushings for the control arms.

I know you think it's the front, but do yourself a favor and replace the RTAB (rear trailing arm bushings). I have powerflex bushing in the entire rear of the car.

Get yourself some nice shocks. If you don't want coils (I did not) get some Bilstein sport shocks and some H&R springs.

Shocks and springs are a day project. I took my car in for the bushings in the rear.

I will tell you this, it's amazing and fun to drive. I recommend everyone do this. It's a sports car, don't forget that
Appreciate 0
      03-17-2020, 10:13 PM   #11
Vanne
Down Under!!
Vanne's Avatar
United Arab Emirates
1593
Rep
4,293
Posts

Drives: 2007 Z4MC
Join Date: Mar 2013
Location: Dubai

iTrader: (4)

Hack! perfect opening statement mate, i cannot agree more with this and thanks for putting it in words.. its only now that i see my way of error in trying to increase turn in by feeding in a little extra steering angle, thus reducing traction further..

I will take this in my mind when next out on the track.

Thank you!
__________________
2007 EuroSpec Z4///MC - Building/Developing Z4 GT3
Powered by
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 10:39 AM.




zpost
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST