BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Today's Posts


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Suspension | Brakes | Chassis
 
Post Reply
 
Thread Tools Search this Thread
      10-29-2009, 06:44 PM   #1
leeor
Banned
United_States
136
Rep
2,386
Posts

Drives: 2010 Blue Prius III
Join Date: Mar 2009
Location: Los Angeles

iTrader: (4)

Would it be weird to go: Front RD, Rear Eibach??

I was wondering if its normal to do the front springs RD sport and the rear eibach?

lol, dont ask why... just curious if thats weird?

Will the ride be stiff or what? bc i know eibach are soft, rd are stiff...

does front or back cause more effect? lol wondering..... anyone know anything?

gimme feed back!
Appreciate 0
      10-29-2009, 11:00 PM   #2
TLud
Colonel
TLud's Avatar
United_States
108
Rep
2,279
Posts

Drives: '12 Golf R
Join Date: Jun 2008
Location: Texas

iTrader: (3)

I would think that it would throw off the balance of the car due to the different spring rates. I wouldn't recommend it.
__________________
'09 Interlagos Blue E92 M3 (sold to a good home)
Appreciate 0
      10-29-2009, 11:15 PM   #3
leeor
Banned
United_States
136
Rep
2,386
Posts

Drives: 2010 Blue Prius III
Join Date: Mar 2009
Location: Los Angeles

iTrader: (4)

thank you, first reply. lets here what else
Appreciate 0
      10-30-2009, 12:06 AM   #4
Lemans_Blue_M
Automotive Industry Insider
Lemans_Blue_M's Avatar
United_States
462
Rep
1,948
Posts

Drives: Lemans Blue M3
Join Date: Aug 2007
Location: Texas

iTrader: (0)

Quote:
Originally Posted by leeor View Post
thank you, first reply. lets here what else
Your car will look "jacked up" as the RD Sport springs in the front will drop the car 1.25", which will look totally out of proportion to the 0.6" drop of the rear Eibach springs. The rake of the car will look weird. (ass end in the air, and front slammed low)

The progressive spring rate difference between the two brands, will also make the car seem like it has a nervous twitch.

This is a very, very, very, VERY bad idea.
__________________
The best is yet to come...
Appreciate 0
      10-30-2009, 12:30 AM   #5
leeor
Banned
United_States
136
Rep
2,386
Posts

Drives: 2010 Blue Prius III
Join Date: Mar 2009
Location: Los Angeles

iTrader: (4)

lol, i never checked the RD drop...however i know its way lower.

my friend told me it was the same in the rear and i forgot what the drop was but ur right, it is .6....

what do you mean it'll look like its twitching?
Appreciate 0
      10-30-2009, 12:44 AM   #6
Lemans_Blue_M
Automotive Industry Insider
Lemans_Blue_M's Avatar
United_States
462
Rep
1,948
Posts

Drives: Lemans Blue M3
Join Date: Aug 2007
Location: Texas

iTrader: (0)

Quote:
Originally Posted by leeor View Post
lol, i never checked the RD drop...however i know its way lower.

my friend told me it was the same in the rear and i forgot what the drop was but ur right, it is .6....

what do you mean it'll look like its twitching?

I mean the RD Sport's progressive spring rate in the front will be much firmer (stiffer) than the softer Eibach springs in the rear.

That will hurt the overall balance & handling characteristics of the car.

This is exactly why all lowering springs are engineered and sold in matched sets(front and rear 4-spring kits), instead of an assortment of 'mix-n-match' pieces.
__________________
The best is yet to come...
Appreciate 0
      10-30-2009, 05:58 AM   #7
Technic
Lieutenant General
Technic's Avatar
2281
Rep
12,997
Posts

Drives: 2021 i3S, 2024 i4 M50
Join Date: Apr 2005
Location: Florida

iTrader: (18)

Quote:
Originally Posted by leeor View Post
lol, i never checked...
That's the real reason that it is a very bad idea.
Appreciate 0
      10-30-2009, 08:13 AM   #8
Radiation Joe
Veni Vidi Vici
Radiation Joe's Avatar
United_States
89
Rep
2,750
Posts

Drives: '11 JB/BBe-6sp-e90
Join Date: Jul 2008
Location: Macungie PA

iTrader: (0)

Garage List
2011 e90 M3-Sold  [8.50]
2003 RS6 - Sold  [0.00]
2009 e90 M3 - Gone  [0.00]
2003 M3 SOLD  [0.00]
old 2002  [10.00]
Quote:
Originally Posted by Lemans_Blue_M View Post
I mean the RD Sport's progressive spring rate in the front will be much firmer (stiffer) than the softer Eibach springs in the rear.

That will hurt the overall balance & handling characteristics of the car.

This is exactly why all lowering springs are engineered and sold in matched sets(front and rear 4-spring kits), instead of an assortment of 'mix-n-match' pieces.
Just playing devil's advocate here, but:

If you know what you are doing, and have a specific goal in mind, I don't have a problem mixing and matching. Spring retailers create a set-up based on what they think the average buyer will like. You may not be the average buyer.

I personally like a very stiff front end and a soft rear end (no comments on that please). When I ordered my springs from Ground-Control for the e46, I was able to set them up to my preferences.

However, if you don't know what you are doing, you can end up with a very strange handling car.
Appreciate 0
      10-30-2009, 10:55 AM   #9
KM3
Formerly K335i
KM3's Avatar
17
Rep
215
Posts

Drives: 2009 E92 M3
Join Date: Jul 2009
Location: Redmond, WA

iTrader: (0)

Quote:
Originally Posted by Radiation Joe View Post
Just playing devil's advocate here, but:

If you know what you are doing, and have a specific goal in mind, I don't have a problem mixing and matching. Spring retailers create a set-up based on what they think the average buyer will like. You may not be the average buyer.

I personally like a very stiff front end and a soft rear end (no comments on that please). When I ordered my springs from Ground-Control for the e46, I was able to set them up to my preferences.

However, if you don't know what you are doing, you can end up with a very strange handling car.
+1

This is a great point, but as Joe mentions, it's extremely important to know how different spring rates are going to affect the handling bias of your car. Your safest bet is to go with the package deal.
__________________

2009 E92 M3 :: Jet Black :: Fox Red Extended :: Carbon Leather :: 6MT :: JRZ RS Suspension :: RD Sport Sways :: StopTech Trophy Brakes :: Cantrell Brake Cooling
Appreciate 0
      10-30-2009, 10:56 AM   #10
SlammedR8
Major General
SlammedR8's Avatar
Canada
521
Rep
5,483
Posts

Drives: 2019 X5 40i/2020 R8 V10 Spyder
Join Date: Jul 2007
Location: Toronto

iTrader: (2)

yesss!
__________________
Current:
2019 BMW X5 40i - Carbon Black/Tartufo Individual Leather
2020 Range Rover HSE - Black/Black
2020 Audi R8 V10 Performance Spyder 6MT - Ascari Blue/Black
Appreciate 0
      10-30-2009, 11:04 AM   #11
FStop7
I like cars
FStop7's Avatar
Vatican City State
329
Rep
5,052
Posts

Drives: M6
Join Date: Oct 2008
Location: Newbury Park, CA

iTrader: (3)

I wish these companies would publish their spring rates. I really would like to use H&R in front and RD in rear, but without knowing the spring rates I won't risk wasting the money.
__________________
Appreciate 0
      10-30-2009, 12:15 PM   #12
Vic55
Lieutenant General
Vic55's Avatar
19335
Rep
10,165
Posts

Drives: 2023 BMW M8 Competition Coupe
Join Date: Jul 2009
Location: THE Orange County

iTrader: (9)

As a layman, I would ask: How many people have done this? Not just here but with other cars? I have seached some sites and the answer is none.

There is a reason why- its been explained by Lemans...
__________________
2024 BMW M3 CS Frozen Solid White
2023 BMW M8 Coupe Competition Alpine White
2022 Porsche Carrera GTS Coupe Shark Blue
2020 Audi R8 V10 Performance Suzuka Gray
2012 Mercedes Benz C63 AMG Black Series Obsidian Black
Appreciate 0
      10-30-2009, 12:56 PM   #13
BarryC
Major
United_States
121
Rep
1,198
Posts

Drives: '15 M3
Join Date: May 2007
Location: Kernersville NC

iTrader: (12)

A completely different thought would be to contact Ground Control as I'm pretty sure they have a "coilover conversion" kit for our cars. Then you can pick whatever ride height and spring rate you want.

BC
__________________
'15 M3, '16 911 Turbo S Cab
Appreciate 0
      10-30-2009, 01:14 PM   #14
leeor
Banned
United_States
136
Rep
2,386
Posts

Drives: 2010 Blue Prius III
Join Date: Mar 2009
Location: Los Angeles

iTrader: (4)

haha yea the drop difference is way far apart from front and back, I know RD is over 1 inch, and the rear we got confused with eibachs and here i came to see that its .6 for the rear drop. But i was just curious to see if such a thing was reasonable to do so or even possible.

Thanks for all your feedback
Appreciate 0
      11-05-2009, 12:49 PM   #15
bogdan
First Lieutenant
bogdan's Avatar
37
Rep
390
Posts

Drives: 911
Join Date: Jan 2009
Location: Rockville, MD

iTrader: (0)

Quote:
Originally Posted by Radiation Joe View Post
Just playing devil's advocate here, but:

If you know what you are doing, and have a specific goal in mind, I don't have a problem mixing and matching. Spring retailers create a set-up based on what they think the average buyer will like. You may not be the average buyer.
Yes, but with GC you probably had a linear spring. The RD, Eibach, Dinan, stock are more than likely progressive rates, so it's not going to be the same effect.

Most track guys will run vastly different spring rates, but not on progressive street springs.

Quote:
I personally like a very stiff front end and a soft rear end (no comments on that please).


Quote:
However, if you don't know what you are doing, you can end up with a very strange handling car.
yes.. tons of hopless understeer.
__________________
gone, not forgotten: Viper | Z06 | E90 M3 | E92 335i
Quote:
Originally Posted by Mjolnir View Post
My dog swallowed my FOB. Luckily it was Comfort Access so I could still drive the car. Of course I had to take him with me everywhere and every time he rolled over the windows went down.
Appreciate 0
      11-05-2009, 03:24 PM   #16
Bluesummer
Lieutenant General
Bluesummer's Avatar
Taiwan
588
Rep
15,818
Posts

Drives: slower than Ayrton Senna
Join Date: Dec 2006
Location: SoCal

iTrader: (15)

Garage List
2017 BMW X5M  [0.00]
2015 M4  [0.00]
2011 E82 135  [0.00]
2011 M3  [0.00]
2007 335  [0.00]
might as well just cut ur stock springs.
__________________
IG:d.violet.m3
Appreciate 0
      11-06-2009, 12:41 AM   #17
StreetLegalR
Second Lieutenant
Netherlands
18
Rep
211
Posts

Drives: 420I GC/M5 E60/M3 E46/CLK55AMG
Join Date: Jul 2005
Location: The Netherlands

iTrader: (2)

I know a few people here in Europe who can make any set lowering springs for you.
But for BMW's he advised, front not lower then 35mm and rear not lower then 25mm.

They made a set for me 10% stiffer then OEM and the following lowering :

Front 28mm (1.10")
Rear 16mm (0.63")

With this set the front and rear gap is almost the same, maybe a difference of 1 or 2mm.

It is a little expensive but it is custom build.
Appreciate 0
Post Reply

Bookmarks


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 07:38 PM.




m3post
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