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E36 racks: let's settle it once and for all.

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    E36 racks: let's settle it once and for all.

    I've seen a lot of misinformation about E36 racks, mainly the ratios, differences and the age-old '95 M3 vs. Z3 rack dilemma. I'd like to set a few things straight. If you have differing info from FIRST-HAND measurements, feel free to correct me, but in 95% of the threads there is just some moron spouting off lock-to-lock numbers off the top of their head, and they're typically wrong about that as well.

    Firstly, all E36 steering racks excluding the '95 M3 rack, and additionally all Z3-M racks are IDENTICAL, save for the '96-99 M3's rack being limited just a bit to allow for the M3's additional caster without affecting tire clearance. The '96-99 M3 racks have about .2 turns less lock-to-lock than the standard E36 rack (3.2 turns LTL instead of 3.4). All of these racks are progressive, meaning that it is slower in the middle of the rack (slower when you're going straight) than towards lock. This was mainly to make the car more relaxed and comfortable at sustained autobahn speeds. The regular E30 rack is about 4 turns lock to lock and the E30 M3 rack is 3.5 turns lock to lock; I am not sure of the total travel distance or overall ratio of either of these, but I can definitely attest to the regular E36 rack being a good improvement in every way over the stock E30 rack.

    Secondly, the '95 M3 rack is SLOWER in the center of the rack and has LESS overall travel than the regular E36 rack. This is mainly because of the different steering geometry of the '95 M3, as you recall they have a different spindle/control arm/CAB setup than the rest of E36 cars. Yes, it's 3 turns flat lock-to-lock but it's still progressive, and the overall degree-to-travel ratio is slower as there is less overall travel. Basically, on any given chassis this rack is inferior to the regular E36 rack despite the lower lock-to-lock number. I know you've read otherwise on E30 sites, and I have too. But, say it with me: screw the '95 M3 rack.

    Thirdly, and most importantly, the Z3 non-M rack, contrary to popular belief, has the SAME overall travel as the run-of-the-mill E36 rack (146mm). However, it's the only rack in the discussion which is linear rate, which means that it's significantly quicker in the center than the other racks, verified by measurement. This is the steering rack to have: 2.7 turns lock to lock, linear, same travel as the regular E36 rack.

    According to RealOEM, all Z3 non-M racks are identical (http://www.realoem.com/bmw/partxref.do?part=32131095575). However, it has been reported first-hand that more than one 1.9 rack has been tried out to have been 3.2 turns lock-to-lock, so try before you buy as RealOEM is not perfect.

    I'm basing this off of a few discussions I've read on E36 forums; the Z3 rack is a common upgrade for E36 M3s and most of them seem to like it. But additionally, if you want cold hard numbers and good info, don't just take my word for it, do some reading for yourself. I'd suggest E36 guys though as they live with different E36 and Z3 racks, as opposed to just going from an abysmal E30 rack to an E36 rack of their choosing and noting a difference, then engaging in a pissing contest when something is questioned. Here are a few pertinent threads:

    http://forums.bimmerforums.com/forum...=steering+rack (gold mine)

    Bimmerforums is the preferred online BMW Forum and community for BMW owners. At Bimmerforums, you will find technical how-to information maintenance specifics audio advice wheel and tire combinations and model specific details not found anywhere else. Our professionals are here to help make sure you find the answers you need to your questions and our community is here to help other brainstorm ideas for the future.


    Bimmerforums is the preferred online BMW Forum and community for BMW owners. At Bimmerforums, you will find technical how-to information maintenance specifics audio advice wheel and tire combinations and model specific details not found anywhere else. Our professionals are here to help make sure you find the answers you need to your questions and our community is here to help other brainstorm ideas for the future.


    Cliffs: Z3 rack > regular E36 rack > '95 M3 rack. Do it.

    #2
    Excellent info.

    I have been thinking about swapping in a Z3 steering rack into my E30, is there anything that needs to be done besides just swapping the racks? Do all of the E30 tie rods work and everything?

    I just think my steering is too slow and its hurting my auto-x times. Even pulling in and out of my garage feels like it takes too much effort on the steering wheel. And is there anyone that has done this swap on a 325is or other E30 that can give their opinion on how it feels on track and street?

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      #3
      Originally posted by Bmil951 View Post
      Excellent info.

      I have been thinking about swapping in a Z3 steering rack into my E30, is there anything that needs to be done besides just swapping the racks? Do all of the E30 tie rods work and everything?

      I just think my steering is too slow and its hurting my auto-x times. Even pulling in and out of my garage feels like it takes too much effort on the steering wheel. And is there anyone that has done this swap on a 325is or other E30 that can give their opinion on how it feels on track and street?
      There is a thread that covers this in detail: http://www.r3vlimited.com/board/showthread.php?t=66247

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        #4
        Thanks!

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          #5
          Thanks for the info. It will come in handy as soon as I can finish turning the steering wheel on my stock e30 rack all the way to the left so I can pull out of my parking space and go buy one.

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            #6
            Good idea for a thread! I have a z3 rack waiting to go in my car right now. Can't wait to see what it feels like.

            '89 Alpine S52 with goodies

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              #7
              I love my 95 M3 rack
              Byron
              Leichtbau

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                #8
                I just got the 3.2 rack i hope i like it -___-

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                  #9
                  I'm surprised this thread hasn't gotten more attention. I was even thinking a sticky is in order, there is a LOT of misinformation out there regarding these steering racks.

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                    #10
                    Wh33lhop explained this to me the other night when I sent him a PM trying to get this stuff straight. This definitely deserves a sticky, as there is so much misconception, bullshit, and "I read it from there, but the other guy read it from here, who heard it from his buddy, who heard it from his buddy's GF's sister's cousin's dog's best friend."

                    Thanks again for the help!

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                      #11
                      Very good information, thanks for posting it. That first Bf.C thread is especially useful, thanks for the link as I almost never go there.

                      Without changing the subject too far, I think this also goes a long ways towards explaining why people have such differing opinions on deleting the power steering pump. With a stock slow E30 rack, you still have enough mechanical advantage that the steering isn't going to feel too heavy. Right now I'm running a E36 non M rack without the pump, and it's pretty easy off center but it's too heavy (IMO) when you go over 90 degrees input at the wheel. This makes sense now that I see that the rack is progressive. I'd hate to feel what a manual Z3 rack would feel like! I do like the steering feedback I get in turns now though, the power assisted steering feels very isolated in comparison.

                      I need to take a couple of pumps to a power steering guru in SoCal, I'd be very interested in a Z3 rack with a lower flow pump.

                      Oh, and I agree this should be stickied, subscribed for further updates.
                      1973 Bavaria

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                        #12
                        I think the E46 M3 rack is just as good as the Z3 rack. That is what I have in our race car.

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                          #13
                          awesome information... I need to find out what rack I have now lol.
                          I got a fender roller now! LMK if you need me to roll your fenders or want to rent the tool from me locally.

                          Paypal: vdang5@gmail.com

                          Delta Auto Care
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                          Herndon, VA
                          703.435.1375

                          My Feedback Thread: Evil_Twin

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                            #14
                            Excellent thread. This deserves a sticky - to dispel the false information floating around out there. I went with a non-M Z3 rack swap after doing extensive research and talking to e30pq that owns 2 E30's - one with a '95 M3 and the other with a non-M Z3, and he confirms the on-center linear feel of the Z3.




                            I must say that the Z3 swap is one of my favorite mods to the car. Steering feel is excellent. It has a nice heavy weight (what you would associate with BMWs). Effort at parking lot speeds is on the high side - and I would even say a bit tiring, but once the car gets up to speeds, it feels just right.

                            If anyone in NJ wants to meet up and go for a test drive, shoot me a PM.
                            Last edited by xphiledan; 06-07-2010, 07:18 AM.

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                              #15
                              Okay, I did not read the entire thread, but in fact I barely read any of it, but all I'm going to say is what wh33lhop's cliffs are correct. Here are some measurements that my friend who races an M coupe took from some race car drivers that took the measurements themeselves:

                              Z3 non-M racks are all the same.
                              - LINEAR ratio (same rack travel per input turn across the entire rack length)
                              - 53.5 mm of linear rack travel per 1 360 degree rotation input.
                              - 144.5 mm of total rack travel (translates to 2.7 turns L2L)
                              - installed 13.9:1 ratio

                              Z3 M racks and '96+ E36 M3 racks are the same.
                              - PROGRESSIVE ratio (rack is slower on-center, quicker towards L&R rack locks)
                              - 45.5 mm of linear rack travel on-center per 1 360 degree rotation input.
                              - 145.6 mm of total rack travel(translates to 3.2 turns L2L)
                              - installed 15.6:1 mean ratio
                              - Same p/n rack as E36 non-M, but locks were modified to shorten gear travel from 154.7 to 145.6mm

                              '95 M3 racks are the slowest and shortest of all US-spec E36 racks, until 200 deg of rotation from on-center.
                              - PROGRESSIVE ratio
                              - 39.0 mm of linear rack travel on-center per 1 360 degree rotation input.
                              - 117mm of total rack travel (translates to 3.0 turns L2L)
                              - installed 17.6:1 mean ratio

                              And btw, regular z3 rack > z3M rack = regular e36 rack

                              So the regular z3 rack would be the best. Sucks for me cuz I JUST had my '95 M3 rack installed after I discovered this info. FML!!!!!

                              /thread
                              -Darius (aka DiscoDoughnuts on other forums)

                              dude man bro...

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