Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E39 (1997 - 2003)

E39 (1997 - 2003)
The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

Reply
 
Thread Tools Display Modes
  #1  
Old 03-15-2011, 10:48 AM
MatWiz's Avatar
MatWiz MatWiz is offline
Psychology Reversalist
Location: NYC
 
Join Date: Jul 2004
Posts: 15,337
Mein Auto: 528
Exclamation The REAL Reason For Using Weights During Alignment (No, It's Not What You Think.)

The REAL Reason For Using Weights During Alignment? (No, It's Not What You Think.)

According to Dinan the purpose of the weights is to simulate the angles in the suspension when the car is driving at high speeds.

When you drive faster, you'd notice that your car "sits down" lower and closer to the road. As the car "sits down lower" the wheels spread wider.

This is caused by the aerodynamics of the car. Slanted windshield, slanted hood, underbelly, etc. BMW designed the car to go lower when you drive faster, not to go higher (float).

The alignment specs are therefor there, because they want specific numbers when you, the driver, need it the most - when you drive the car like it was meant to be driven. Not while you are at your shopping center parking lot driving speed. Makes sense?

The instruction by BMW is to do this:
1. Place the weights in the car.
2. Measure the height of the car: "fender to center of the wheel" to make sure the car is at the right height. The tolerance is 1cm (or a quarter of an inch IIRC - but it is very close to that anyway).

Anecdotal:

1)
I did my alignment a few time at a Dinan installer. He does it the way it is described above. His explanation to the use of weights was the down force at speed due to aerodynamics.

Results: With only me, the driver, in the car, and no passengers, the car handling and overall feel was "Amazing and Fantastic".

2)
I did my alignment twice at an indy shop that specialize in preparing and building M3 cars for race tracks. The owner does the alignment himself. In the past, BMW used him to travel around the country to teach dealership technicians how to do alignment. So this is a guy who teaches BMW how do alignment (it's worth repeating this twice).

The way that HE approaches the alignment is a little different than the above. He puts weights on the strut towers and in the trunk and keeps measuring the HEIGHT of the car (fender to center wheel) until the HEIGHT of the car is exactly in the middle of the spec provided by BMW. So basically, he doesn't care what the weight is. He just wants to make sure that the HEIGHT is perfect.

I asked him what's his purpose in doing it that way. HIS explanation is, that the purpose of the weights is to bring to suspension to be perfectly parallel to the ground. THEN you align the wheels to the correct numbers in the BMW spec.

After the alignment, he takes the car for a ride in some twisty back roads, that ends in a large empty parking lot where he will drive in a figure 8 at high speed making sure everything is just superb. Fun times.

It makes perfect sense to me.

Results: With me, the driver, as the only person in the car. No passengers. The car handling and overall feel was... you've guessed it. Beyond your expectation Fantastic and Amazing. You WILL feel the difference even if you are not Mario Andretti.


NOBODY EVEN MENTIONED THE WEIGHT OF PASSENGERS, ETC.

I DON'T KNOW OF ANY BMW DOCUMENTATIONS WHO MENTION WEIGHT OF PASSENGERS.

As a reference point: Up to that time, I used to take my car to a place who did my alignment without weights "because his machine compensated for the lack of weights in the BMW". He was very precise and I always watched while he's doing it. He always brings it to the middle of the spec. Guess what? The car felt "okay", but not even resembling the feel of the car after the two above shops did it using the weights. There was no resemblance whatsoever.

I can unequivocally say, based on my experience after the alignment, comparing the last one to the first two, that the first two guys alignment is perfectly correct, and the last one is absolutely wrong for the car. And that is AT ANY SPEED.

Do yourself a big favor and take your car to a shop that does the alignment like BMW says to do it.

Lastly, just a tip to the new guys looking for an alignment shop:
1. Ask if they use weights, if they don't, walk away.
2. Ask for a printout of the before and after. If they tell you that the printer is broken or they run out of ink or whatever other BS they tell you, walk away.
3. Try very very hard to go to a place that specializes in BMW or high end cars. Even if it means that you need to drive farther, or need to pay more.
4. Stay there to watch the alignment if at all possible (dealers will not allow you to watch, but they are ok of course).

Good luck!

MatWiz
__________________
MatWiz
"Seeing is not believing. Believing is seeing." -Judy the Elf

Last edited by MatWiz; 03-15-2011 at 11:16 AM.
Reply With Quote
Ads by Google
  #2  
Old 03-15-2011, 10:53 AM
doru's Avatar
doru doru is offline
Officially Welcomed to the 'Fest
Location: Calgary
 
Join Date: Sep 2007
Posts: 4,428
Mein Auto: 2003 530iA
Good info Mat.
Oh! I forgot! Your name is not Mat!



Thanks for sharing
__________________
Looking for a DIY? Parts? Check this out, it might be your ticket
TMS underdrive pullies - Stewart WP - PSS9 - Beisan Vanos seals - Zimmerman cross-drilled & Akebono Euro - Deka 649 MF - 55w HID headlights - 35w HID foglights - Hualigan double din - ACS (rep) alu pedals - Euro central storage console - Breyton Magic Racing staggered wheels - M5 bumper - M5 steering wheel - Tint
Stable: e39, e53, e46 & Tribby
Reply With Quote
  #3  
Old 03-15-2011, 10:57 AM
MatWiz's Avatar
MatWiz MatWiz is offline
Psychology Reversalist
Location: NYC
 
Join Date: Jul 2004
Posts: 15,337
Mein Auto: 528
Quote:
Originally Posted by doru View Post
Good info Mat.
Oh! I forgot! Your name is not Mat!



Thanks for sharing
haha!

You are welcome.

Dan
__________________
MatWiz
"Seeing is not believing. Believing is seeing." -Judy the Elf
Reply With Quote
  #4  
Old 03-15-2011, 11:03 AM
menhir's Avatar
menhir menhir is offline
Float On
Location: Macungie, PA
 
Join Date: May 2010
Posts: 460
Mein Auto: 1981 320i
This is perfect! I'll be shopping around for the right alignment shop soon.

Thanks!
Reply With Quote
  #5  
Old 03-15-2011, 11:08 AM
Jason5driver's Avatar
Jason5driver Jason5driver is offline
Officially Welcomed to the 'Fest
Location: Middle of a corn field
 
Join Date: May 2007
Posts: 4,449
Mein Auto: E39 hamster w/ pin-wheel
Interesting...
My highly-regarded Alignment shop says that they can align the car without weights, just do it through the computer.
Their computer can compensate for the weights...
__________________
Reply With Quote
  #6  
Old 03-15-2011, 11:13 AM
AnotherGeezer's Avatar
AnotherGeezer AnotherGeezer is offline
Hofmeister Kink
Location: ManchVegas, New Hampster
 
Join Date: Dec 2009
Posts: 3,723
Mein Auto: 2003 530i/5
My angels are doing just fine thankyouverymuch.
__________________
Reply With Quote
  #7  
Old 03-15-2011, 11:15 AM
MatWiz's Avatar
MatWiz MatWiz is offline
Psychology Reversalist
Location: NYC
 
Join Date: Jul 2004
Posts: 15,337
Mein Auto: 528
I just edited the OP. I forgot to mention that as the car drives faster, and "sits down lower", the wheels spread wider.

mw
__________________
MatWiz
"Seeing is not believing. Believing is seeing." -Judy the Elf
Reply With Quote
  #8  
Old 03-15-2011, 11:19 AM
MatWiz's Avatar
MatWiz MatWiz is offline
Psychology Reversalist
Location: NYC
 
Join Date: Jul 2004
Posts: 15,337
Mein Auto: 528
Quote:
Originally Posted by AnotherGeezer View Post
My angels are doing just fine thankyouverymuch.


I sure hope so!

Sorry for the amount of typos and spelling in the original version, my internet was down, and I wrote it quickly without spell checking and without proof reading first. Bummer.

Thanks for the tip. I've changed it to angles..

mw
__________________
MatWiz
"Seeing is not believing. Believing is seeing." -Judy the Elf
Reply With Quote
  #9  
Old 03-15-2011, 11:23 AM
bluebee's Avatar
bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
 
Join Date: Mar 2008
Posts: 19,190
Mein Auto: 02 BMW 525i M54 automatic
This expert advice is a must to add to the alignment links in the bestlinks sticky thread:

- The dozen BMW alignment specs and which are adjustable on the E39 (1) & how to DIY caster, camber & toe at home (0) (1) (2) (3) (4) (5) (6) (7) (8) (9) and how to make your own alignment tools (1) & the theory of alignment with (1) or without adding weight (1) (2) (3)
Reply With Quote
  #10  
Old 03-15-2011, 11:28 AM
bobdmac bobdmac is online now
Officially Welcomed to the 'Fest
Location: Back in Oaktown, Yay Area
 
Join Date: Feb 2011
Posts: 2,224
Mein Auto: 2001 540i/6, '90 BMW k75s
Quote:
Originally Posted by MatWiz View Post

[/FONT] According to Dinan the purpose of the weights is to simulate the angels in the suspension when the car is driving at high speeds.

When you drive faster, you'd notice that your car "sits down" lower and closer to the road.

[FONT=Verdana]This is caused by the aerodynamics of the car. Slanted windshield, slanted hood, underbelly, etc. BMW designed the car to go lower when you drive faster, not to go higher (float)....
This sounds dubious. Has BMW ever made any such claims? Most cars produce lift as the air flows over them, thus the need for spoilers to counteract it and keep the wheels planted. Looking at a profile of the car, it's hard to see what would overcome the Bernoulli effect of the roof curvature. Race cars resort to under-body ducts, or air tunnels, to produce downforce.

You may be right, but I'd like to see some citation other than "someone told me." Is there anything in writing from Dinan on this?
Reply With Quote
  #11  
Old 03-15-2011, 12:27 PM
cn90 cn90 is offline
Officially Welcomed to the 'Fest
Location: Omaha NE
 
Join Date: Mar 2006
Posts: 12,315
Mein Auto: 1998 528i 5-sp 103K miles
I don't know about this Dinan non-sense but BMW engineers are little bit paranoid about this alignment issues.

Whether it is a Toyota, Honda, Mercedes, or BMW, the principle of alignment and parallelism are very very similar.

The nose of most cars tend a dive a tiny bit at high speed. High speed here means speed approaching an airline taking off speed (180-200 mph)!
And very few cars drive at that speed!

So for most of us who drive at legal speeds of 60-80 mph, this speed is not enough to lower the nose and cause lift for that matter.
I did the alignment without weight and with myself as the driver. The 150lb or so lowers the front by exactly 1 cm, not enough to change any specs such as toe-in or camber.

"bobdmac", this is good reading!
http://www.imps4ever.info/tech/aero/tech_aero.htm
Reply With Quote
  #12  
Old 03-15-2011, 12:36 PM
newton22 newton22 is offline
Officially Welcomed to the 'Fest
Location: Texas
 
Join Date: May 2009
Posts: 152
Mein Auto: E36, E39
Gentlemen, I see you have discovered the phenomenon of downforce.
__________________
Reply With Quote
  #13  
Old 03-15-2011, 12:40 PM
bobdmac bobdmac is online now
Officially Welcomed to the 'Fest
Location: Back in Oaktown, Yay Area
 
Join Date: Feb 2011
Posts: 2,224
Mein Auto: 2001 540i/6, '90 BMW k75s
Quote:
Originally Posted by cn90 View Post
"bobdmac", this is good reading!
http://www.imps4ever.info/tech/aero/tech_aero.htm
Link isn't responding for me.
Reply With Quote
  #14  
Old 03-15-2011, 12:44 PM
QSilver7's Avatar
QSilver7 QSilver7 is online now
Officially Welcomed to the 'Fest
Location: Northeast Indiana
 
Join Date: Aug 2008
Posts: 5,385
Mein Auto: 1997 740iL / 2006 X5 4.4
Just an FYI for those that didn't know about wheel alignment and the recommended weight BMW suggests:


It appears the specs were the same from my e34 Bentley Service Manual:

__________________
Q {BMW CCA Member #191509}
2006 E53 X5 4.4i (Sterling Gray) 12/05 mfg date <<~>> 97 740iL (Arctic Silver) 3/97 mfg date
(SOLD)
99 540iT (Orient Blue) <<~>> 95 525IT (Alpine White)
91 735iL (Schwarz Black) <<~>> 85 325e (Bronzit)

http://imageshack.com/scaled/grid240/822/e38e532ndsigpic.jpg

Last edited by QSilver7; 03-15-2011 at 12:47 PM.
Reply With Quote
  #15  
Old 03-15-2011, 01:16 PM
MatWiz's Avatar
MatWiz MatWiz is offline
Psychology Reversalist
Location: NYC
 
Join Date: Jul 2004
Posts: 15,337
Mein Auto: 528
Quote:
Originally Posted by newton22 View Post
Gentlemen, I see you have discovered the phenomenon of downforce.
Coming from Newton (get it? "Newton" - downforce - apples- ), this post is priceless!!


Guys, you are welcome to give more weight ( ) to the wisdom of either the first man, or the second man. As for myself bringing the suspension to parallel with whatever the weight is, makes sense if you want the alignment to be factory spec, and precise. The issue if this is because of downforce or parallelism is secondary to me. The point is that if you make sure that the suspension is at the right height and THEN you do your alignment, you'd come out perfect.

If you do your alignment when the car is too high, your alignment is incorrect. It is as simple as that. You'd be outside of the specs.

Now I know some of you would say "so what if I am out of specs?". Well, to be honest, my post is not intended to you. My post is intended to those fanatics who like to get into their car after this alignment and say to themselves "Holly Sh*t! Now I understand how the E39 suppose to feel like", and have a big grin over their face. EVEN when driving at speed limit on the highway.

My post is also an important point to those who upgrade parts on their car. Upgrades cost money and time. You do this because you want or hope that the car will perform better. You also hope that you will NOTICE and FEEL the difference. Well here is my promise to you: Do the alignment the way it is described in the OP, and that will be one of the best "performance upgrades" you've done and WILL FEEL. Doing an alignment the wrong way, is really a "performance downgrade" from a standard stock E39. - Think about it.

My post is also to anybody who ASKS a question about alignment. I think that anybody who is concerned enough to even post a question here about alignment, understands the importance of it and wants to do it right.

The point is, all the components are already there, installed at the factory and designed with a lot of thoughts by the engineers. You can either make use of it, and align it to the specs the way it suppose to be. OR, you can say whatever, save the $50 or so difference and go to gas station alignment shop and have your car aligned to a "eh, close enough for me" out of specs.

mw
__________________
MatWiz
"Seeing is not believing. Believing is seeing." -Judy the Elf

Last edited by MatWiz; 03-15-2011 at 01:17 PM.
Reply With Quote
  #16  
Old 03-15-2011, 01:26 PM
bobdmac bobdmac is online now
Officially Welcomed to the 'Fest
Location: Back in Oaktown, Yay Area
 
Join Date: Feb 2011
Posts: 2,224
Mein Auto: 2001 540i/6, '90 BMW k75s
Quote:
Originally Posted by MatWiz View Post
The point is that if you make sure that the suspension is at the right height and THEN you do your alignment, you'd come out perfect.
This I can agree with.
Reply With Quote
  #17  
Old 03-15-2011, 01:32 PM
MatWiz's Avatar
MatWiz MatWiz is offline
Psychology Reversalist
Location: NYC
 
Join Date: Jul 2004
Posts: 15,337
Mein Auto: 528
Quote:
Originally Posted by QSilver7 View Post
Just an FYI for those that didn't know about wheel alignment and the recommended weight BMW suggests:


It appears the specs were the same from my e34 Bentley Service Manual:

See the instruction reading "Ride height is in accordance with specifications"? (I wish you could highlight it in yellow. I don't know if you highlighted the other part of your pic. If you can, please do!).

Notice that nobody almost ever mentioned ride height in any of the discussions we've had in many of the threads here about weighted alignment.

That in the most important piece in the alignment preparation. How many shop technicians even know about ride height? I doubt many do.

mw
__________________
MatWiz
"Seeing is not believing. Believing is seeing." -Judy the Elf
Reply With Quote
  #18  
Old 03-15-2011, 01:38 PM
bobdmac bobdmac is online now
Officially Welcomed to the 'Fest
Location: Back in Oaktown, Yay Area
 
Join Date: Feb 2011
Posts: 2,224
Mein Auto: 2001 540i/6, '90 BMW k75s
Just so it's clear, I didn't intend to argue the merits of taking ride height into consideration when aligning the suspension. I just don't know enough about the suspension to argue one way or the other. My argument concerned whether aerodynamics actually lowered ride height at highway speed.
Reply With Quote
  #19  
Old 03-15-2011, 02:08 PM
bobdmac bobdmac is online now
Officially Welcomed to the 'Fest
Location: Back in Oaktown, Yay Area
 
Join Date: Feb 2011
Posts: 2,224
Mein Auto: 2001 540i/6, '90 BMW k75s
Quote:
Originally Posted by cn90 View Post
"bobdmac", this is good reading!
http://www.imps4ever.info/tech/aero/tech_aero.htm
I'm disappointed the link is still non-responsive, but if you're talking about this car, it needs all the aerodynamic help it can get:

Reply With Quote
  #20  
Old 03-15-2011, 03:52 PM
Calicoastin Calicoastin is offline
Officially Welcomed to the 'Fest
Location: East Bay/Peninsula, California
 
Join Date: Jan 2009
Posts: 178
Mein Auto: 2003 E39 540i auto
How does this technique of loading the suspension affect tire wear?
Reply With Quote
  #21  
Old 03-15-2011, 04:59 PM
Fudman's Avatar
Fudman Fudman is offline
Officially Welcomed to the 'Fest
Location: Sudbury, MA
 
Join Date: Apr 2007
Posts: 6,052
Mein Auto: '02 530i Sport auto
Dan:
A very good post. But the bottom line is that BMW is the only source that knows the REAL REASON behind weighting of the car before an alignment. I have total respect for Dinan and other shops specializing in BMWs but their rationalizing the "real reason" behind weighting is really just speculation. It may be 100% accurate but until BMW weighs in and backs it up, it is just a well educated guess that is backed up by the butt dyno effect.

This forum could really use an inside source (a Deep Throat) to explain the real why behind what BMW did when designing this car.
Reply With Quote
  #22  
Old 03-15-2011, 06:35 PM
540iman's Avatar
540iman 540iman is offline
resident, old fart
Location: N.W. Indiana
 
Join Date: Sep 2008
Posts: 1,502
Mein Auto: 2002 540i sport
Quote:
Originally Posted by MatWiz View Post
I just edited the OP. I forgot to mention that as the car drives faster, and "sits down lower", the wheels spread wider.

mw
I buy that the car sits lower at speed, but not sure I agree that wheels actually spread apart farther, but you do what you believe. An experienced alignment shop can easily compensate for not having the car at speed or extra weight. Alignment is very predictable unless you have a real problem with the car. You car just as easily load down the car and align....remove the weights and note the difference. Good points though, nonetheless!
Reply With Quote
  #23  
Old 03-15-2011, 07:29 PM
MatWiz's Avatar
MatWiz MatWiz is offline
Psychology Reversalist
Location: NYC
 
Join Date: Jul 2004
Posts: 15,337
Mein Auto: 528
Quote:
Originally Posted by Calicoastin View Post
How does this technique of loading the suspension affect tire wear?
Less wear. Especially at the rear (where the wear is at worst).

Here is why: You suppose to have 2 degrees camber at the rear. You press the car, the camber increases.

So, lets just use these numbers for the example, because I am just making them up, ok? Lets say that when the car is neutral (standing, no weights) the camber is 2 degrees. You press it down to spec ride height, and you'd get 2.5 (as an example).

If you now align the car (pressed), you will dial that camber down by 0.5 to bring it to 2.0. Now you remove the weights, and your camber at neutral is 1.5.

So what happen is this: You don't put weights, and adjust to 2.0, and you'd have MORE camber then BMW wants, and you'd wear the inside of the rear tires MORE then if you'd bring it to 2 when pressed down.

Because it suppose to be 2.0 when pressed, not when raised.

mw
__________________
MatWiz
"Seeing is not believing. Believing is seeing." -Judy the Elf
Reply With Quote
  #24  
Old 03-15-2011, 07:49 PM
MatWiz's Avatar
MatWiz MatWiz is offline
Psychology Reversalist
Location: NYC
 
Join Date: Jul 2004
Posts: 15,337
Mein Auto: 528
Quote:
Originally Posted by Fudman View Post
Dan:
A very good post. But the bottom line is that BMW is the only source that knows the REAL REASON behind weighting of the car before an alignment. I have total respect for Dinan and other shops specializing in BMWs but their rationalizing the "real reason" behind weighting is really just speculation. It may be 100% accurate but until BMW weighs in and backs it up, it is just a well educated guess that is backed up by the butt dyno effect.

This forum could really use an inside source (a Deep Throat) to explain the real why behind what BMW did when designing this car.
The 'other shop", the man that trained dealer's alignment techs, was trained by BMW factory engineers. I honestly don't remember if he was brought to Germany for the training, or somebody from Germany came here to train him. But you can be sure that they didn't picked him out of nowhere and just sent him to teach their dealerships. He'd have to go through the whole factory training. So I would take HIS word over Dinan, even though we know that Dinan talks to BMW factory engineers too. (He is an approved BMW tuner).

I want to say that he (the specialist) went to Germany, but I am not 100% sure I remember it. He was also a Bosch specialist and ran a Bosch shop, so I don't remember if he went to Germany for that one.

Anyway, you know what, here he is: http://www.mrmcar.com/bio/short.html Read and see.. LOL ... I'm sure you'd be impressed. If you wanted a BMW insider, he is one VERY insider.

mw
__________________
MatWiz
"Seeing is not believing. Believing is seeing." -Judy the Elf

Last edited by MatWiz; 03-15-2011 at 07:52 PM.
Reply With Quote
  #25  
Old 03-15-2011, 08:07 PM
MatWiz's Avatar
MatWiz MatWiz is offline
Psychology Reversalist
Location: NYC
 
Join Date: Jul 2004
Posts: 15,337
Mein Auto: 528
Quote:
Originally Posted by 540iman View Post
I buy that the car sits lower at speed, but not sure I agree that wheels actually spread apart farther, but you do what you believe. An experienced alignment shop can easily compensate for not having the car at speed or extra weight. Alignment is very predictable unless you have a real problem with the car. You car just as easily load down the car and align....remove the weights and note the difference. Good points though, nonetheless!
Of course they do. You press the car, the camber increases. Increased camber = less distance between the top of the two wheels on that axis, and increased distance between the bottom of the wheels on that axis.

I just grabbed this from Google search. Look what happens when you lower (or press down) the car. The camber is increased.




Camber increase = wheels spread wider.

mw
__________________
MatWiz
"Seeing is not believing. Believing is seeing." -Judy the Elf
Reply With Quote
Reply

Bookmarks

Tags
alignment, alignment with weights, camber, weights


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E39 (1997 - 2003)
Today's Posts Search
Thread Tools
Display Modes

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 On



Forum Jump


All times are GMT -7. The time now is 07:57 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms