Announcement

Collapse
No announcement yet.

e46 M3 suspension setup, or how to not downgrade your car with suspension mods

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Originally posted by bigjae46 View Post
    Maybe I missed it but how low can you go in the rear before you start compromising suspension geometry?

    I’m 13.5 left and 13.75 right fender to center of wheel in the front but 12.75 left and 13 right in the rear measured with no driver. I’m right at 50/50 crossweights with the driver. My seating position is far enough back so my fat arse distributes more weight to the rear. So I’m sure the rear heights with me in it are lower.

    Im really happy with the car’s performance as is. I’ve lucked out and been able to balance the car out with aero. I’m wondering if I can get a little more mechanical grip in the rear so I can take off the gurney flap which adds a ton of drag with my Amazon.com wing that I bought with Hilton points 🤣
    Very little change from lowering the rear, camber and track changes are basically linear, and the roll center barely moves. You’re just fine

    edit: you lose anti-squat performance from lowering the rear, still probably not a huge deal but you’ll be giving up a little rear grip on acceleration as you’ll increase negative camber just when you want positive (near zero) camber for traction.
    Last edited by Bry5on; 06-05-2023, 08:35 PM.
    ‘02 332iT / 6 | ‘70 Jaguar XJ6 electric conversion

    Comment


      Originally posted by Maxima SE View Post

      I have the B12 Pro kit on my Z4M with 19" tires and the drop is lovely but hitting the smallest pothole makes it sound like you slammed into a brick wall. Even the oem suspension with 18" tires sounded like that. Just a very stiff chassis. Everytime I hit a pothole I feel like I bent a wheel. On smooth roads its a comfortable ride otherwise and the thing handles amazin !
      They Z cars are interesting. They lacks the travel of the sedans and coupes from which they’re mostly built on. So, lowering them puts you in situation where you go from very little travel to almost nothing.

      Comment


        Originally posted by tlow98 View Post

        They Z cars are interesting. They lacks the travel of the sedans and coupes from which they’re mostly built on. So, lowering them puts you in situation where you go from very little travel to almost nothing.
        Are you sure about this? I do not see why the Z would not have the same exact travel as the M3. It is basically the e36 m3 front suspension mated to the e46 m3 rear suspension. Any of these cars are not exactly soft stock. Putting 19s on a Z would be bad for the ride on its own, lowering it on top of that would certainly explain any ride degradation.

        As for the cat asking about B4/Dinan and whatever...I say keep stock springs no matter what shock. I have now gone from stock to lowering springs and back to stock on both my Ms and could not be happier.

        Comment


          Originally posted by 01SG View Post

          Are you sure about this? I do not see why the Z would not have the same exact travel as the M3. It is basically the e36 m3 front suspension mated to the e46 m3 rear suspension. Any of these cars are not exactly soft stock. Putting 19s on a Z would be bad for the ride on its own, lowering it on top of that would certainly explain any ride degradation.

          As for the cat asking about B4/Dinan and whatever...I say keep stock springs no matter what shock. I have now gone from stock to lowering springs and back to stock on both my Ms and could not be happier.
          I'm quoting Jason Cammissa when I say that. My understanding is the springs are shorter (and the bump stops are certainly shorter). Shocks are shorter and have different bodies, as well. I love the cars, but straying from stock and shortening the already shortened suspension is a tough pill to swallow. They are generally a bit lighter which helps, I think. FWIW, I have not compared each component in my hand with the Z4 gen, tho, I have with the E36/7 gen. They are most certainly lacking travel compared to the E36.

          Comment


            Interesting. I figured the harsher ride simply came from the stiffer chassis and sitting over the rear wheels.

            Comment


              Z4M shocks have 5in of travel. I compared the stock v h and r and travel wise they were the same. So lowering the car just ate travel. I think e46 have also 5in of total strut travel.

              Comment


                Originally posted by maupineda View Post
                Z4M shocks have 5in of travel. I compared the stock v h and r and travel wise they were the same. So lowering the car just ate travel. I think e46 have also 5in of total strut travel.
                Stock e46 M3 rear has 4.5” droop, 5” bump, 1.4” until contacting the bump stop
                Click image for larger version

Name:	IMG_4780.jpg
Views:	479
Size:	112.9 KB
ID:	220895 Click image for larger version

Name:	IMG_4779.jpg
Views:	485
Size:	130.3 KB
ID:	220894
                Attached Files
                ‘02 332iT / 6 | ‘70 Jaguar XJ6 electric conversion

                Comment


                  Originally posted by Bry5on View Post

                  Stock e46 M3 rear has 4.5” droop, 5” bump, 1.4” until contacting the bump sto
                  Any chance you know what these stock numbers are for the front?
                  '04 LSB Coupe 6MT
                  All my money goes towards maintenance.

                  Comment


                    Originally posted by dukeofchen View Post

                    Any chance you know what these stock numbers are for the front?
                    Sadly I do not, it’s a little harder to measure this directly. I’m interested if someone does have them!
                    ‘02 332iT / 6 | ‘70 Jaguar XJ6 electric conversion

                    Comment


                      Originally posted by Bry5on View Post

                      Stock e46 M3 rear has 4.5” droop, 5” bump, 1.4” until contacting the bump stop
                      Click image for larger version

Name:	IMG_4780.jpg
Views:	479
Size:	112.9 KB
ID:	220895 Click image for larger version

Name:	IMG_4779.jpg
Views:	485
Size:	130.3 KB
ID:	220894
                      I was referring to the fronts. Then i noted i used the wrong terminology. I meant struts

                      for the rear, the B8 were a good 25mm shorter. So droop was the same shorter

                      i will find some photos a they can be of use to some

                      Comment


                        Originally posted by Obioban View Post
                        I increasingly feel like the more I know about suspension, the less I know about suspension.

                        ... and that deviating from stock as little as possible (but as much as necessary) is the best strategy-- especially in ride height and geometry.
                        For me the hardest part as I learn more is letting go of things I thought were true. And then realizing I was wrong yet again just weeks/months later! Also, understanding there is no "right" answer, and instead multiple solutions. And what works for one person might not work for another.




                        Regarding the lowering discussion, there is just hardly any room to lower the E46 if you want to maintain civility and performance. I highly recommend not lowering it more than a teeny tiny bit unless you run shorter shocks to maintain some travel before hitting the bump stops. And then you have to be careful about the tire hitting the fenders or fender liners. Not to mention all the geometry stuff that gets messed up when you start lowering.

                        Then again some people just want it to look cool and don't care how it rides. To each their own!

                        Comment


                          If you go bigger sway bars, may I suggest you reinforce the sway bar mounting area with Bimmerworld's reinforcement kit (https://www.bimmerworld.com/BimmerWo...i-330i-M3.html). Just a thought after last weekend.

                          Feff
                          Attached Files
                          MVP Track Time

                          Comment


                            Originally posted by Feffman View Post
                            If you go bigger sway bars, may I suggest you reinforce the sway bar mounting area with Bimmerworld's reinforcement kit (https://www.bimmerworld.com/BimmerWo...i-330i-M3.html). Just a thought after last weekend.

                            Feff
                            Yikes!

                            Comment


                              Originally posted by cobra View Post
                              Yikes!
                              This is a common know failure yours truly did not know about. The learning curve never ends. 🤑

                              Feff

                              MVP Track Time

                              Comment


                                Originally posted by Feffman View Post

                                This is a common know failure yours truly did not know about. The learning curve never ends. 🤑

                                Feff
                                Obioban knows nothing about this

                                Nothing at all
                                2008 M3 Sedan 6MT
                                Slicktop, no iDrive | Öhlins by 3DM Motorsport | Autosolutions | SPL

                                2012 Mazda5 6MT
                                Koni Special Active, Volvo parts

                                Comment

                                Working...
                                X