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E36 Steering Rack Ratios

Printed From: Bavarian-Board.co.uk - BMW Owners Discussion Forum
Category: Frequently Asked Questions
Forum Name: BMW FAQs
Forum Discription: Where all the commonly asked questions are answered
URL: http://www.bavarian-board.co.uk/forum_posts.asp?TID=25831
Printed Date: 21-April-2021 at 03:06


Topic: E36 Steering Rack Ratios
Posted By: Pooky
Subject: E36 Steering Rack Ratios
Date Posted: 10-January-2006 at 12:21
There has been some mis-information for a while about the E36 rack ratios plus I remember someone on here running an E36 3.0 M3 rack in their E30. I have spent some time doing some measurements plus confirmed this data direct with ZF (I know someone who works there who can access drawings on their system).

 

The standard way ZF quote on-centre (straight ahead) ratio is in mm/rev, which is the travel in mm of the rack bar per revolution of the hand wheel. The higher the mm/rev the faster the rack.

 

M3 3.0 - 39 mm/rev - the slowest available rack. This is a variable ratio but it is slower than standard until 200 deg hand wheel angle

 

M3 3.2 and standard E36 - 45.5 mm/rev - the M3 3.2 rack has restricted lock.

 

Z3 rack - 53.5 mm/rev - by far the quickest rack you can fit.

 

E46 compact rack - 50 mm/rev - apparently this also fits the E36

 

Because the M3 3.0 has a variable rack it has the smallest lock to lock at 3.0 turns but donít be fooled it is the slowest by a country mile. A worthwhile upgrade for any 3.0 M3 (or a track based E30 with one of these fitted) would be to fit a standard E36 rack (or even a Z3 rack) which is what I did a year ago with a noticeable improvement.



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Replies:
Posted By: sleeper
Date Posted: 10-January-2006 at 12:38
good advice! thanks!

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Posted By: BMG M3
Date Posted: 10-January-2006 at 13:10
Great information.


Posted By: bmwcrazy
Date Posted: 10-January-2006 at 13:12
nice one 

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Posted By: bhp555
Date Posted: 10-January-2006 at 14:46

Pooky,

As always, good info......

I've run a stock e36 rack in an M3 as well and I'm not sure, (in my experience) I'd bother changing the rack in the 3.0l M3 e36 to a standard e36 one........ but I suppose you can't argue with the facts if you intend to change the rack in an e30, it make sense to go for the quicker rack.

The idea of the variable rack in the M3 was too make it speed sensitive.....not too everyones liking, but it cetainly worked, i.e slower at low speeds.

While you are talking to your man at ZF ask about the e36 320 rack, as fitted to the later 320i M52 variant, I seem to remember an urban myth surrounding this one....(it has a different part number to the rest of the range 316 - 328).....



Posted By: bmwcrazy
Date Posted: 10-January-2006 at 15:16
A+++++++++++ POOKY

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Posted By: 215DMX
Date Posted: 10-January-2006 at 16:35
Don't forget that the length of the steering arms will
also have an effect as to the overall ratio.

A Z3 rack on a e36 'should' have a different ratio as
opposed to when it is mounted on a Z3 for example
because of different fittment (though it would be
quicker than the original e36 rack)

Excellent info though.

I've been looking for a LHD Z3 rack for a while now...


Posted By: M3PSM
Date Posted: 10-January-2006 at 18:23
Pooky, is the Z3 rack a direct replacement or is a lot of cunning jiggery pokery required?
The steering has always been my biggest complaint on my car (brakes aside)

Paul

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Drive it like you stole it!
___________________________
1995 3.0 E36 Coupe
1989 E30 325 Touring
1992 Yamaha TDM 850
www.myallracing.co.uk


Posted By: Pooky
Date Posted: 11-January-2006 at 02:51

Originally posted by 215DMX 215DMX wrote:

Don't forget that the length of the steering arms will
also have an effect as to the overall ratio.

A Z3 rack on a e36 'should' have a different ratio as
opposed to when it is mounted on a Z3 for example
because of different fittment (though it would be
quicker than the original e36 rack)

Excellent info though.

I've been looking for a LHD Z3 rack for a while now...

Of course the overall steering ratio between hand wheel and road wheel is a combination of steering arm length, column phasing and steering rack ratio so this is just a comparison of rack ratios that could be fitted to the E36.

The Z3 rack bolts straight on just needs a small bracket to mount the pipes - approx 50mm flat plate. Have a look on e36coupe as M3 compact supplied a picture.



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Posted By: 215DMX
Date Posted: 11-January-2006 at 04:36
I seem to remember the e30 M3 rack is something
around 45mm/rev and the std e30 rack something
like 37/38mm/rev.


Posted By: Ian Godney
Date Posted: 11-January-2006 at 05:49
Bummer - I bought a 3:0 M3 rack a while ago then spent over £100 last week having it re-conned , oh well a Z3 rack it is then

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www.godspeedbrakes.co.uk


Posted By: UJM3
Date Posted: 11-January-2006 at 07:45

Great info pooky...



Posted By: dougster
Date Posted: 11-January-2006 at 08:04
Great info and very useful!


Posted By: CoolCat
Date Posted: 11-January-2006 at 14:32

YEESSS great info Pooky. Thanks.

Same as M3PSM, for me this is THE one thing to change on the M3 Evo. Even more so when I drive it again after having driven my brother's Evo VI...



Posted By: CoolCat
Date Posted: 11-January-2006 at 16:41

Hi Pooky,

Do you have the part number of the Z3 rack. Or at least what type of Z3 exactly?
As I'm just having a look at BMW references, and that of the Z3M is the same as the M3 Evo, so can't find out...

Thanks



Posted By: 215DMX
Date Posted: 11-January-2006 at 16:48
32 13 1 095 575
Z3 1.9 rack + others (that's for LHD)


Posted By: UweM3
Date Posted: 19-October-2006 at 10:06
just digging that old post out again to see if there any updates/news to report.

My steering rack needs replacement and I am undecided if I should recondition mine or get a Z3 1.9.

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E61 520d, slow and buzzy but my wallet likes the mpg.....


Posted By: flyingalexf68
Date Posted: 19-October-2006 at 12:41
Interesting reading. I only have my e36 M3 3.0 a few weeks but I find the steering is ridiculously slow. I can't understand why the M department thought it was a good idea. I used to have a Z3 and the steering was nice and quick. (Even thought the steering wheel was way way way too big). It's a mod I'll stick on my to do list.

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1995 e36 3.0 M3 Coupe, Daytona Violet, AP Racing BBK, CCFL Angel Eyes, M3 Spoiler, M-Tec 3 Steering Wheel.   
2000 530d Steptronic, Poverty Spec, 18" Alloys.


Posted By: denishogan
Date Posted: 24-October-2006 at 11:33
How many turns lock to lock with the Z3 rack? And is there any specific Z3 rack to look for? i.e. one out of a 4 pot or a 6 pot Z3

Cheers,
Denis


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http://www.irishhillclimb.com - Irish Hillclimb and Sprint Championship


Posted By: flyingalexf68
Date Posted: 24-October-2006 at 12:33

Originally posted by denishogan denishogan wrote:

How many turns lock to lock with the Z3 rack? And is there any specific Z3 rack to look for? i.e. one out of a 4 pot or a 6 pot Z3

Cheers,
Denis

Can't remember the turns lock to lock but there is a very tight corkscrew type hill near me and I have to turn the wheel in my M3 much further going around the bends. I had a 2.2 Z3. Also the steering wheel in the M3 is ~380mm compared to the ~370mm in the Zed and my 5 series, which feel noticeably smaller.



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1995 e36 3.0 M3 Coupe, Daytona Violet, AP Racing BBK, CCFL Angel Eyes, M3 Spoiler, M-Tec 3 Steering Wheel.   
2000 530d Steptronic, Poverty Spec, 18" Alloys.



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