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  • Suspension set up guru's (Not spring and shock related)

    Theres a few things i would like to discuss with you guys. I want to start piecing together the "other suspension" components before I install the H&R race / Billie combo.

    FRONT:

    - Did some research and seems like ST sway bar set is the way to go?
    - 96+ M3 front LCA center the wheel right?
    - anybody use MASSIVE strut to LCA spacer to improve suspension travel

    Rear :

    -Subframe bushings. How many of you needed to use the raised subframe bushings to fix excessive rear neg camber? Im on sport springs now and Ive got to be like -3.5 deg camber in the rear lol. or is this a result of really worn subframe bushings? i would like to only replace them once haha.


    I guess thats really it , Thanks
    sigpic 95 M3 & 88 M3

  • #2
    WRT Sway bars, the higher the spring rate the less work the sway bars contribute to roll stiffness. SO, so long as you have a facility to make adjustments, then fine enough.

    WRT E36 arms, I can't comment. There is lots of threads on here. Can't see why stock arms with offset bushes would not work.

    If you are insisting on going real low (bad idea IMO), using LCA (Roll centre spacers) spacers will restore stock roll centre and bump steer.

    The best way to lower the rear is to raise the subframe. This helps maintain stock geometry. The excess camber is a result of the arc in which the trailing arm traces and the camber/toe change as a result.

    My advice would be to try to maintain as close to stock ride height as possible. You can use different thickness spring pads to adjust ride height.
    .
    Also, trim the bump stops contained inside the Bilstein front strut inserts. Reducing the length by half does wonders for ride quality.

    https://s14net.vbulletin.net/forum/s...eel-this-still



    Sport Evo No.47

    My Sport Evo Restoration

    Comment


    • #3
      Sway bars depend on spring rate. After trying 4 different sets of springs and 3 different sets of dampers, I have come to the conclusion that the only springs with enough spring rate to keep the car off the bump stops all the time are a set of Turner J stock springs. (640/1080 lb). Also, you need the bump steer spacers to correct your roll center (you will need 16+ inch wheels for these to fit).

      On the rear, I used the subframe riser bushings to get my camber back to decent. I tried using a set of the Ireland engineering spring spacers with the sock bushings, but they didn't raise the back end enough (I took them out with the riser bushings). The one downside to riser bushings is that there is very little space between the subframe and the body, making the diff install a serious headache, as well as there being very very little space between the top of the subframe and the fuel filler hose going into the tank.

      I have about 10K miles on the car since doing the rear bushings back in August of this year. (Yeah I drive my car) Tire wear is much improved and the car feels fantastic.

      Will
      '69 Datsun 2000 Roadster vintage race car (Street driven on a regular basis :taz
      '59 Alfa Romeo 101 Sprint (HUGE project :uhoh
      '88 M3

      Comment


      • #4
        Originally posted by stevesingo View Post
        WRT Sway bars, the higher the spring rate the less work the sway bars contribute to roll stiffness. SO, so long as you have a facility to make adjustments, then fine enough.

        WRT E36 arms, I can't comment. There is lots of threads on here. Can't see why stock arms with offset bushes would not work.

        If you are insisting on going real low (bad idea IMO), using LCA (Roll centre spacers) spacers will restore stock roll centre and bump steer.

        The best way to lower the rear is to raise the subframe. This helps maintain stock geometry. The excess camber is a result of the arc in which the trailing arm traces and the camber/toe change as a result.

        My advice would be to try to maintain as close to stock ride height as possible. You can use different thickness spring pads to adjust ride height.
        .
        Also, trim the bump stops contained inside the Bilstein front strut inserts. Reducing the length by half does wonders for ride quality.

        https://s14net.vbulletin.net/forum/s...eel-this-still


        good info in that thread i need to finish reading it when i get out of work
        sigpic 95 M3 & 88 M3

        Comment


        • #5
          Originally posted by RAD2LTR View Post
          Sway bars depend on spring rate. After trying 4 different sets of springs and 3 different sets of dampers, I have come to the conclusion that the only springs with enough spring rate to keep the car off the bump stops all the time are a set of Turner J stock springs. (640/1080 lb). Also, you need the bump steer spacers to correct your roll center (you will need 16+ inch wheels for these to fit).

          On the rear, I used the subframe riser bushings to get my camber back to decent. I tried using a set of the Ireland engineering spring spacers with the sock bushings, but they didn't raise the back end enough (I took them out with the riser bushings). The one downside to riser bushings is that there is very little space between the subframe and the body, making the diff install a serious headache, as well as there being very very little space between the top of the subframe and the fuel filler hose going into the tank.

          I have about 10K miles on the car since doing the rear bushings back in August of this year. (Yeah I drive my car) Tire wear is much improved and the car feels fantastic.

          Will
          Wow good info here. what shocks are you running? I also have access to a lift so the install wont be too bad since i have all winter to do it. I see you drive a lot! As do i on the weekends and it helps that our Cars and Coffee is about 40 min away. Its always a good run.

          Thanks
          sigpic 95 M3 & 88 M3

          Comment


          • #6
            Originally posted by RAD2LTR View Post
            Sway bars depend on spring rate. After trying 4 different sets of springs and 3 different sets of dampers, I have come to the conclusion that the only springs with enough spring rate to keep the car off the bump stops all the time are a set of Turner J stock springs. (640/1080 lb). Also, you need the bump steer spacers to correct your roll center (you will need 16+ inch wheels for these to fit).

            On the rear, I used the subframe riser bushings to get my camber back to decent. I tried using a set of the Ireland engineering spring spacers with the sock bushings, but they didn't raise the back end enough (I took them out with the riser bushings). The one downside to riser bushings is that there is very little space between the subframe and the body, making the diff install a serious headache, as well as there being very very little space between the top of the subframe and the fuel filler hose going into the tank.

            I have about 10K miles on the car since doing the rear bushings back in August of this year. (Yeah I drive my car) Tire wear is much improved and the car feels fantastic.

            Will
            Your issue WRT keeping the car clear of the bump stops seems to be a shock stroke length issue. GrpA cars had a raised strut tower so they could run a longer length strut and keep the same travel.
            Sport Evo No.47

            My Sport Evo Restoration

            Comment


            • #7
              My M3's front suspension has Jstock shock and springs, Vorshlag camber plates, Massive 16mm roll center spacers, and 22mm Bimmerworld swaybar. The rear is still the stock swaybar but obvious suspension like mentioned. The car is incredibly flat through corners, composed over bumps, and comfortable on the road.

              If you are going to lower your car a bunch I would propose looking into the Bimmerworld swaybar setup. It has a 2" drop in the rear swaybar to compensate for lowered cars. Most e30 sway bars run a 22/19mm setup.

              Regarding control arms, I don't entirely see the point of running the e36 M3 control arm unless you're looking for looks. The alignment on my car puts the car back in the wheel well, but the car feels great. I'm even running 17x8 e20 with 215/40 tires and I have no rub.

              Lastly, regarding roll center spacers...I have two sets of 16mm spacers from Massive on two e30s and it reduces bump steer. Both have different suspensions but it helps.
              1987 325is - 185-195k
              1988 M3 - 141k

              Comment


              • #8
                I will also give a vote for the J-Stock. On my first track car I built I used the J-Stock setup primarily so that there wouldn't be any adjustments to make and I could focus on driving and not setup. Frankly, it was sublime. I sent me existing Bilsteins in to Bilstein for a revalve to match Turners J-Stock setup and found a used set of springs. I ran suspension techniques 22mm Front and 19mm Rear sway bars.

                The car was very flat, very predictable and very forgiving. I really like it. Now I have adjustable stuff and it's a constant game for a while trying to get it just right -- J Stock is faster and more compliant out of the box for most drivers

                Comment


                • #9
                  Originally posted by enigmaticdream View Post
                  My M3's front suspension has Jstock shock and springs, Vorshlag camber plates, Massive 16mm roll center spacers, and 22mm Bimmerworld swaybar. The rear is still the stock swaybar but obvious suspension like mentioned. The car is incredibly flat through corners, composed over bumps, and comfortable on the road.

                  If you are going to lower your car a bunch I would propose looking into the Bimmerworld swaybar setup. It has a 2" drop in the rear swaybar to compensate for lowered cars. Most e30 sway bars run a 22/19mm setup.

                  Regarding control arms, I don't entirely see the point of running the e36 M3 control arm unless you're looking for looks. The alignment on my car puts the car back in the wheel well, but the car feels great. I'm even running 17x8 e20 with 215/40 tires and I have no rub.

                  Lastly, regarding roll center spacers...I have two sets of 16mm spacers from Massive on two e30s and it reduces bump steer. Both have different suspensions but it helps.
                  I'm running the stock rear bar as well. I have GC camber plates, but they are the worst investment I have made on the car. I should have bought the Vorshlag ones. My one change to the setup is a set of TC Klein externally adjustable Koni Sports. They don't have the compression damping, but they do have adjustable rebound damping (cranked full hard)

                  In the previous setups I've run Bilstein HDs, Bilstein Sports, and the TC Klein dampers. The first set of springs with the BHDs, the dampers were poorly matched to the springs. I got the TC Kleins, good god that was a bad idea, not enough spring rate, it bottomed while pulling into my garage (only in the front however, the back was good.) I replaced those springs with the H&R race springs, and it bottomed just the same. I installed the roll center spacers to fix the roll center, and it helped, but I was still bottoming out over everything. Installed the Bilstein sports, bottomed out slightly less (more compression damping) but would still bottom out over things like steel plates in the road. Found the J stock springs, installed them. Perfection. I left the TC Klein Konis in and the ride is great, firm but not harsh. It does bottom from time to time, but not hard. I have the J stock bilstein dampers sitting in the garage, but I've never used them. The car is so well dialed with this setup that I put my girlfriend in the car for her first autoX. She wasn't that comfortable driving the car, but she went out and finished mid field, beating a lot of seasoned drives. I finished 2/10 sec off top time of the day. (it wasn't a big autoX but there were some good drivers.) I have zero complaints about the setup other than the GC camber plates. The only change I have made recently was to go back to 15 inch wheels so the roll center spacers had to come out. I haven't noticed a big difference. The car is better with them, but its not bad in any way without them. If I ever decide to go back to the 16 inch wheels, the spacers will go back in.

                  Will
                  '69 Datsun 2000 Roadster vintage race car (Street driven on a regular basis :taz
                  '59 Alfa Romeo 101 Sprint (HUGE project :uhoh
                  '88 M3

                  Comment


                  • #10
                    Originally posted by RAD2LTR View Post

                    I'm running the stock rear bar as well. I have GC camber plates, but they are the worst investment I have made on the car. I should have bought the Vorshlag ones. My one change to the setup is a set of TC Klein externally adjustable Koni Sports. They don't have the compression damping, but they do have adjustable rebound damping (cranked full hard)

                    In the previous setups I've run Bilstein HDs, Bilstein Sports, and the TC Klein dampers. The first set of springs with the BHDs, the dampers were poorly matched to the springs. I got the TC Kleins, good god that was a bad idea, not enough spring rate, it bottomed while pulling into my garage (only in the front however, the back was good.) I replaced those springs with the H&R race springs, and it bottomed just the same. I installed the roll center spacers to fix the roll center, and it helped, but I was still bottoming out over everything. Installed the Bilstein sports, bottomed out slightly less (more compression damping) but would still bottom out over things like steel plates in the road. Found the J stock springs, installed them. Perfection. I left the TC Klein Konis in and the ride is great, firm but not harsh. It does bottom from time to time, but not hard. I have the J stock bilstein dampers sitting in the garage, but I've never used them. The car is so well dialed with this setup that I put my girlfriend in the car for her first autoX. She wasn't that comfortable driving the car, but she went out and finished mid field, beating a lot of seasoned drives. I finished 2/10 sec off top time of the day. (it wasn't a big autoX but there were some good drivers.) I have zero complaints about the setup other than the GC camber plates. The only change I have made recently was to go back to 15 inch wheels so the roll center spacers had to come out. I haven't noticed a big difference. The car is better with them, but its not bad in any way without them. If I ever decide to go back to the 16 inch wheels, the spacers will go back in.

                    Will
                    Yeah the Vorshlag camber plates are really nice. I went with them over GC because you can "upgrade" to a 2.5" setup down the road if you wanted for cheap. For the 4 or 5 years I've h ad them they've never popped or made any nasty noises. I occasionally put a drop of oil into the bearing, especially before autox/track weekends.

                    The j stock dampeners are pretty nice as well. The rear are inverted shocks which help reduce some weight and shorten the rear extension by about 2" (iirc). For instance if I jack my car up from the frame rail I can have front and rear on the side being jacked up on jackstands in no time. So easy.
                    1987 325is - 185-195k
                    1988 M3 - 141k

                    Comment


                    • #11
                      Originally posted by RAD2LTR View Post

                      I'm running the stock rear bar as well. I have GC camber plates, but they are the worst investment I have made on the car. I should have bought the Vorshlag ones. My one change to the setup is a set of TC Klein externally adjustable Koni Sports. They don't have the compression damping, but they do have adjustable rebound damping (cranked full hard)

                      In the previous setups I've run Bilstein HDs, Bilstein Sports, and the TC Klein dampers. The first set of springs with the BHDs, the dampers were poorly matched to the springs. I got the TC Kleins, good god that was a bad idea, not enough spring rate, it bottomed while pulling into my garage (only in the front however, the back was good.) I replaced those springs with the H&R race springs, and it bottomed just the same. I installed the roll center spacers to fix the roll center, and it helped, but I was still bottoming out over everything. Installed the Bilstein sports, bottomed out slightly less (more compression damping) but would still bottom out over things like steel plates in the road. Found the J stock springs, installed them. Perfection. I left the TC Klein Konis in and the ride is great, firm but not harsh. It does bottom from time to time, but not hard. I have the J stock bilstein dampers sitting in the garage, but I've never used them. The car is so well dialed with this setup that I put my girlfriend in the car for her first autoX. She wasn't that comfortable driving the car, but she went out and finished mid field, beating a lot of seasoned drives. I finished 2/10 sec off top time of the day. (it wasn't a big autoX but there were some good drivers.) I have zero complaints about the setup other than the GC camber plates. The only change I have made recently was to go back to 15 inch wheels so the roll center spacers had to come out. I haven't noticed a big difference. The car is better with them, but its not bad in any way without them. If I ever decide to go back to the 16 inch wheels, the spacers will go back in.

                      Will

                      This is interesting and right along what I am wanting to do soon. I love bilsteins but bump stop is too long and HR springs are too soft...
                      Koni I think are the better street option which is what I'm going for.

                      The problem is J-stock springs are NLA... And i have no idea what springs would be comparable. What would be a good way to build a very similar setup? I don't want the dampers doing the job of the springs. I assume the TCK konis (link to where to buy same ones?) but what springs?? And what #?

                      Comment


                      • #12
                        I want to bump this thread to talk more about rear sway bars. I'm currently running 400F/650R springs with an IE 25mm hollow front bar (same stiffness as a 22mm bar) and a stock rear bar. My initial reason for doing this was I heard about some successful racers running no rear bar with very stiff rear springs to aid in compliance and putting power down in the corners. Along those lines, I was thinking if I went a bit stiffer in the rear from the standard 400/600 spring setup, I could get away with a stock rear bar. I've been running this way for a few years but recently, as my car does more track days than street driving, I've been considering a stiffer rear ARB. I see a few people here have stayed with the stock rear ARB. What is the reasoning for this?
                        What are the thoughts on upgrading the rear ARB? Unnecessary? Will it hurt traction? (I love being able to stomp the throttle well before he apex). What rear spring rate would make a rear ARB unnecessary? I'm currently considering the IE 19mm rear ARB.
                        "It is needless to say that self-propelling vehicles, like other machines, will never do as much for one who does not understand them as for one who does."

                        Comment


                        • #13
                          Based on my research Will Turner was competitive in J Stock running his springs (640/1080) and ST sway bars (22mm/19mm) along with specially valved Bilstein dampers. My feeling is go with a proven design / setup, especially a track-proven setup.

                          That said I think the answer is dependent upon:
                          1) Your damper rates and how well matched they are to your springs
                          2) Tires (r-comp or street)
                          3) Camber / caster / alignment settings

                          Successful racers are running slicks or r-comps and this makes a huge difference on how you setup your suspension. Do you have more specifics on these racers and their setup?

                          I think the answer to your question is "it depends."

                          Comment


                          • #14
                            You already have stiffer spring in the rear, and going to a stiffer rear bar should induce more oversteer.

                            I had my car out on an autoX back in february and it was totally neutral. Conditions were intermittent heavy rain mixed with hints that it was going to dry out. I was rusty, but by the afternoon I was holding TTOD, a time set during a torrential downpour. Go figure. Eventually I was beaten by a stripped out Mitsubishi EVO race car, but it was a fluke run (You only need to get it right once to take TTOD) I was very impressed by how easy my car was to drive, and I only managed to spin it once (Got my left foot stuck under the brake pedal while left foot braking...)

                            Since the J stock springs are available from Turner again, I'd go that route. I'm still super happy with the car and how it handles. On the track I think it would be pretty quick for what it is.

                            Will
                            '69 Datsun 2000 Roadster vintage race car (Street driven on a regular basis :taz
                            '59 Alfa Romeo 101 Sprint (HUGE project :uhoh
                            '88 M3

                            Comment


                            • #15
                              Originally posted by mwagner10702 View Post
                              Based on my research Will Turner was competitive in J Stock running his springs (640/1080) and ST sway bars (22mm/19mm) along with specially valved Bilstein dampers. My feeling is go with a proven design / setup, especially a track-proven setup.

                              That said I think the answer is dependent upon:
                              1) Your damper rates and how well matched they are to your springs
                              2) Tires (r-comp or street)
                              3) Camber / caster / alignment settings

                              Successful racers are running slicks or r-comps and this makes a huge difference on how you setup your suspension. Do you have more specifics on these racers and their setup?

                              I think the answer to your question is "it depends."
                              That's good to hear that Turner's J-stock setup worked well with the 19mm rear bar. I think that points to it being even more important for a car will less rear spring. I don't know the setups of these other cars, but I'd be curious to know what spring rate you need to not run a rear bar.
                              "It is needless to say that self-propelling vehicles, like other machines, will never do as much for one who does not understand them as for one who does."

                              Comment

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