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
      10-26-2019, 01:07 PM   #1
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
Getting rear ride height right on coilovers

I just installed coilovers on my Z4MC and lowered the rears too low. Almost 1.5 inch drop. I know it's too low because now the rear wheels have visible negative camber.

How much drop is too much on the rears? How do you guys decide your ride height in general? Stick with stock for best performance, or is slightly lowered better? How much lower?

How do alignment shops do the alignment for rear wheels? I read different things about it online. Some say it's only adjusted by the spring height. I've seen mention of an eccentric bushing.

Also, how do you guys make sure your front/rear ride heights are balanced, i.e not too much drop on one vs the other.

Also, will the alignment shop adjust my ride height and shift the front struts around to fix camber? Idk what these shops actually do beside put the car on a machine and attach the sensors to the wheels.

Thanks for the help.
Appreciate 0
      10-28-2019, 11:00 AM   #2
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
Answered some of my own questions -

rear alignment:
https://www.newtis.info/tisv2/a/en/e...rement/FxWnmWJ

confirmation that adjusting ride height sucks and therefore alignment shop will prob not do this:
https://www.zpost.com/forums/showthread.php?t=729211
Appreciate 0
      10-28-2019, 11:51 AM   #3
Azeka1
Track Junkie
Azeka1's Avatar
Albania
237
Rep
393
Posts

Drives: E86 M Coupe
Join Date: Jun 2017
Location: NJ

iTrader: (2)

Garage List
The rear height would be determined by the front height, this is called 'Rake'. My last track alignment had me at F: 25.5 R: 25.

Depending on where you're located in NY, we have a lot of really good performance shops that can assist you.

Also, you might want to consider Ground Control articulating weight jacks in the rear to make adjustment easier. Hope this helps!
__________________
2006 E86 M Coupe | Silver Gray / Imola | JRZ RSTWO | SS Headers | Rouge Exhaust| APEX ARC-8 | APR Aero | Sparco Seats/Belts | Weichers Cage | Solid Motor/Trans/Shifter/SubFrame | Poly Bushings | Race Camber Plates/Arms | CSF Rad/Oil | BW Brake Ducts | Braille Battery | AC/EGR Delete | 3,100lbs
1991 SW20 MR2 Turbo | Widebody | 400WHP/355TRQ | 2017 Audi Q7 | 2010 VW CC 2.0T
Gone: 2014 Audi A6 | 2011 G37 S Coupe 6MT | 2004 G35 Coupe
Appreciate 0
      10-28-2019, 01:05 PM   #4
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
Thanks Azeka, do you have recommendations near Brooklyn?
Appreciate 0
      10-28-2019, 04:13 PM   #5
Azeka1
Track Junkie
Azeka1's Avatar
Albania
237
Rep
393
Posts

Drives: E86 M Coupe
Join Date: Jun 2017
Location: NJ

iTrader: (2)

Garage List
Quote:
Originally Posted by filtercoffee View Post
Thanks Azeka, do you have recommendations near Brooklyn?
You're welcome! It might be a little bit of a hike with traffic, but Rogue Engineering in NJ would be a great resource that is around 30 miles or so away.

Also New Palumbo's in Millburn, NJ is owned by a BMW club racer that really knows his stuff.
__________________
2006 E86 M Coupe | Silver Gray / Imola | JRZ RSTWO | SS Headers | Rouge Exhaust| APEX ARC-8 | APR Aero | Sparco Seats/Belts | Weichers Cage | Solid Motor/Trans/Shifter/SubFrame | Poly Bushings | Race Camber Plates/Arms | CSF Rad/Oil | BW Brake Ducts | Braille Battery | AC/EGR Delete | 3,100lbs
1991 SW20 MR2 Turbo | Widebody | 400WHP/355TRQ | 2017 Audi Q7 | 2010 VW CC 2.0T
Gone: 2014 Audi A6 | 2011 G37 S Coupe 6MT | 2004 G35 Coupe
Appreciate 0
      10-28-2019, 07:52 PM   #6
3002 tii
Lieutenant General
3002 tii's Avatar
United_States
1354
Rep
11,765
Posts

Drives: Z4M, X3 35i, i3 REx
Join Date: Apr 2008
Location: CT

iTrader: (91)

Garage List
Rake matters to certain extent but ideally your indiv heights are based on corner balancing. Also factor in what camber settings are and how much tire you can practically stuff without rubbing.
__________________
Follow for latest mods

Last edited by 3002 tii; 10-28-2019 at 08:32 PM..
Appreciate 3
longress102.50
Azeka1237.00
Vanne1078.50

      10-28-2019, 08:29 PM   #7
longress
Second Lieutenant
longress's Avatar
United_States
103
Rep
230
Posts

Drives: 2007 Z4M Coupe
Join Date: Oct 2015
Location: Wyoming

iTrader: (2)

Quote:
Originally Posted by 3002 tii View Post
Rake matters to certain extent but ideally your indiv heights are based on corner balancing. Also factor in what camber settings are and how much tire you can practically stuff without running.

👆🏻This
Appreciate 0
      10-28-2019, 11:42 PM   #8
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
If I'm getting the car corner balanced, I guess I don't need to bother with the ride height adjustment at all?

Also is it just me or is ride height adjustment is > 50% of the work of installing coilovers properly? Since you have to tweak drive the car around, rinse and repeat. Corner adjustment places might as well install the coilovers too, no?
Appreciate 0
      10-29-2019, 07:39 PM   #9
3002 tii
Lieutenant General
3002 tii's Avatar
United_States
1354
Rep
11,765
Posts

Drives: Z4M, X3 35i, i3 REx
Join Date: Apr 2008
Location: CT

iTrader: (91)

Garage List
Quote:
Originally Posted by filtercoffee View Post
If I'm getting the car corner balanced, I guess I don't need to bother with the ride height adjustment at all?

Also is it just me or is ride height adjustment is > 50% of the work of installing coilovers properly? Since you have to tweak drive the car around, rinse and repeat. Corner adjustment places might as well install the coilovers too, no?
On a roadster the install is more involved because of additional trim removal but for a coupe it’s pretty straightforward. Setting initial ride height from a visual standpoint is only time consuming if you’re going so low (slammed) that you’re looking for ever mm to close that gap without rubbing or bottoming out. But I’ve learned over the years that ‘waiting for springs to settle’ is over blown and whatever static height you get is pretty much it. The Rogue rear adjusters are nice but it’s just essentially cutting out the time spent on jacking up the car and removing the wheel.

If you’re looking to corner balance, then yes it’s time consuming but only because you can’t adjust the car while it’s on a lift. Every adjustment needs to be made while it’s sitting on the scales so it basically takes a shop the same time as it would take you. But more important is whoever is doing the corner also takes care of your alignment at same time. Assuming you got adjustable camber plates installed with the coilovers?

Just keep in mind that a proper corner balance can get really expensive. So unless you’re chasing tenths, it may not be worth the cost, especially if you plan on messing with ride height down the road. Else just pick something that’s visually appealing yet practical and make sure your alignment is dialed in.
__________________
Follow for latest mods
Appreciate 0
      10-29-2019, 08:34 PM   #10
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
My rear ride height lowered significantly after a day of hard driving. Not sure why. i hope it's not because the shocks are bad. Hopefully just the springs were not seated or my car hasn't settled after driving it up a level of my condo parking garage. Will take another look this weekend. I agree that if you just assume static ride height is correct, the job of setting ride height isn't too bad.
Appreciate 0
      10-29-2019, 09:43 PM   #11
3002 tii
Lieutenant General
3002 tii's Avatar
United_States
1354
Rep
11,765
Posts

Drives: Z4M, X3 35i, i3 REx
Join Date: Apr 2008
Location: CT

iTrader: (91)

Garage List
Quote:
Originally Posted by filtercoffee View Post
My rear ride height lowered significantly after a day of hard driving. Not sure why. i hope it's not because the shocks are bad. Hopefully just the springs were not seated or my car hasn't settled after driving it up a level of my condo parking garage. Will take another look this weekend. I agree that if you just assume static ride height is correct, the job of setting ride height isn't too bad.
What setup did you buy and how many miles on it? What length spring and how much adjustment do you have left on the perch?
__________________
Follow for latest mods
Appreciate 0
      10-29-2019, 09:49 PM   #12
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
Fortune auto msc-1. I don't know the exact mileage but probably 20-30k miles. the ring is 2 inches up on the perch, I think the swift springs are 5". I have roughly another 2 inches or more to go.
Appreciate 0
      10-29-2019, 10:26 PM   #13
ZeD4Mr
Major
ZeD4Mr's Avatar
Canada
373
Rep
1,277
Posts

Drives: MR
Join Date: Dec 2009
Location: B.C. Canada

iTrader: (18)

Quote:
Originally Posted by filtercoffee View Post
Fortune auto msc-1. I don't know the exact mileage but probably 20-30k miles. the ring is 2 inches up on the perch, I think the swift springs are 5". I have roughly another 2 inches or more to go.
Will you be tracking at all? Always wonder if those Coilover are good enough for the track.
__________________


FB Group-- > fb.com/groups/z4group
Instagram --> @Skyermotorsport
FB Page-- > fb.com/Skyermotorsport
Appreciate 0
      10-30-2019, 09:34 AM   #14
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
I will probably not be tracking this year, maybe next year. If you're ever in NY, let me know, you can test it out.
Appreciate 0
      11-02-2019, 03:26 PM   #15
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
I'm 23" or 584mm on the rears, measured from the bottom of the rim up to the fender, which is a 10mm drop from the stock ride height of 594. The rear wheels still seem too cambered, by my visual estimate.

Front is 23.8" or 604mm, which is close to the stock height of 607mm. So i'll probably drop it a bit more, till it's a 10mm drop all around, then take it for an alignment.
Appreciate 0
      11-03-2019, 10:47 PM   #16
3002 tii
Lieutenant General
3002 tii's Avatar
United_States
1354
Rep
11,765
Posts

Drives: Z4M, X3 35i, i3 REx
Join Date: Apr 2008
Location: CT

iTrader: (91)

Garage List
Quote:
Originally Posted by filtercoffee View Post
I'm 23" or 584mm on the rears, measured from the bottom of the rim up to the fender, which is a 10mm drop from the stock ride height of 594. The rear wheels still seem too cambered, by my visual estimate.

Front is 23.8" or 604mm, which is close to the stock height of 607mm. So i'll probably drop it a bit more, till it's a 10mm drop all around, then take it for an alignment.
So you raised it back up and that put you at 23”? Or that’s what you had before when you said rears were too low? 10mm is less than half inch... that’s not much of a drop at all TBH.

Also try measuring from center of hub to fender instead.
__________________
Follow for latest mods

Last edited by 3002 tii; 11-03-2019 at 11:11 PM..
Appreciate 0
      11-04-2019, 09:32 AM   #17
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
Quote:
Originally Posted by 3002 tii View Post
So you raised it back up and that put you at 23Ē? Or thatís what you had before when you said rears were too low?
I raised it back up (about half an inch) and that's what put me at 23".

Quote:
Originally Posted by 3002 tii View Post
10mm is less than half inch... thatís not much of a drop at all TBH.
Yep. I think I'm going to stick with it, i don't feel an urge to go lower. I got the coilovers for performance.

Quote:
Originally Posted by 3002 tii View Post
Also try measuring from center of hub to fender instead.
Will do.
Appreciate 0
      01-30-2020, 03:35 PM   #18
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
Got it aligned properly. My rear camber was previously -2.9 degrees on each side. They adjusted it to the minimum they could, which was -2.3 degrees on each side. Visually, it looks more normal

Fronts are at -1.4. Not too dramatic.

Also, front total toe .2, rear total toe .4.
Appreciate 0
      02-01-2020, 07:53 PM   #19
Vanne
Down Under!!
Vanne's Avatar
United Arab Emirates
1079
Rep
3,882
Posts

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

iTrader: (4)

lol id go that ,but backwards.. -2.3 in the front and -1.4 in the rear. weird that you cant get less than 2.3 in the rear?? isnt spec something like -1.5 in the rear?? how are your bushes?
__________________
2007 EuroSpec Z4///MC - Building/Developing Z4 GT3
Powered by Severn Tuning

Appreciate 0
      02-01-2020, 08:00 PM   #20
filtercoffee
I like Coffee & Z4s.
43
Rep
238
Posts

Drives: 2007 Z4MC
Join Date: Feb 2019
Location: New York, NY

iTrader: (1)

Garage List
2007 BMW Z4MC  [0.00]
No issues with ride quality so I think bushes are fine but I haven't really checked to be honest. I think lowering in the rear changes the camber pretty quickly.
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 01:22 PM.




zpost
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, 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