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Should new Bilstein sports feel this still.

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  • #91
    Sorry, I didn't.

    Don't suppose you want to share your CAD .dwg file.
    Sport Evo No.47

    My Sport Evo Restoration

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    • #92
      Managed to get out for 100miles last night over a mix of urban, open roads and motorway to evaluate the cut down bump stops.

      Just to recap, springs are 150Fr/435Rr lb/in with Bilstein Sports running stock ride height and 24mm front ARB and 16mm Rear ARB

      On urban roads it is definitely less crashy, particularly of speed humps.

      On the motorway, as you would expect, there is no real difference aside from dips caused by subsidence deliver less of a thud through the front end.

      On the open road, the car is recognisably better composed, particularly at high speed over crests and dips, and no bottoming out or splitter scraping.

      Cornering; at lower speed, front end grip is better with less tendency to push in to understeer, likely due to the reduction in front roll stiffness.

      Overall, I think the trimming of the bump stops is a must do and the spring/damper match I now have is ideal for fast (some of last night sweepers were 100mph+) road driving.

      My next move is to go for some GC Touring mounts. I have fitted E90 top hats which drop 10mm, but as the drop is achieved by increasing the distance between the spring platforms, this uses 10mm of damper travel. By replacing these with stock top hats and get my 10mm drop from reducing the thickness of the top mount, I get back my 10mm of damper travel and keep my 10mm drop.

      A word of caution on cutting the bump stops: If you are really low (not recommended as it will screw with the roll centres), you may still run out of travel and not have sufficient bump stop to cushion the bottoming out, at which point you have no suspension.
      Sport Evo No.47

      My Sport Evo Restoration

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      • #93
        Originally posted by stevesingo View Post
        Managed to get out for 100miles last night over a mix of urban, open roads and motorway to evaluate the cut down bump stops.

        Just to recap, springs are 150Fr/435Rr lb/in with Bilstein Sports running stock ride height and 24mm front ARB and 16mm Rear ARB

        On urban roads it is definitely less crashy, particularly of speed humps.

        On the motorway, as you would expect, there is no real difference aside from dips caused by subsidence deliver less of a thud through the front end.

        On the open road, the car is recognisably better composed, particularly at high speed over crests and dips, and no bottoming out or splitter scraping.

        Cornering; at lower speed, front end grip is better with less tendency to push in to understeer, likely due to the reduction in front roll stiffness.

        Overall, I think the trimming of the bump stops is a must do and the spring/damper match I now have is ideal for fast (some of last night sweepers were 100mph+) road driving.

        My next move is to go for some GC Touring mounts. I have fitted E90 top hats which drop 10mm, but as the drop is achieved by increasing the distance between the spring platforms, this uses 10mm of damper travel. By replacing these with stock top hats and get my 10mm drop from reducing the thickness of the top mount, I get back my 10mm of damper travel and keep my 10mm drop.

        A word of caution on cutting the bump stops: If you are really low (not recommended as it will screw with the roll centres), you may still run out of travel and not have sufficient bump stop to cushion the bottoming out, at which point you have no suspension.
        Reviving an old thread. Thinking about swapping out my stock shocks for Bilsteins. I was leaning towards keeping the springs stock, but reading this has made me think of upgrading the springs too. What brand/model springs are you using to get those spring rates with the stock ride height? If the springs are the same length as stock, is there a reason to get the Bilstein sport shocks over the HD's?

        Thanks!

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        • #94
          I too am thinking of updating my suspension to Coilovers. Currently have H&R sport springs with Bilsteins.

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          • #95
            This is a great thread! First off, I thought Bilsteins had internal bump stops? I thought this was a key difference between Bilstein and Koni. That would make this whole thread moot since you shouldn't be running external bump stops at all, so maybe I'm wrong. Maybe that's just the case with new Bilsteins.
            Secondly, what springs give you stock ride height with 150/435 rates?

            My understanding of e30 shock options is that Bilsteins may be very stoutly built, but they are over damped on compression. This effectively does the job of the spring, and while making the turn-in amazing, is unnecessary as it does the job which should be done by a spring (compression resistance). Koni, on the other hand, relies on rebound damping to control the car, which has the benefits of the car "jacking down" instead of "jacking up" on transitional corners. Meaning it wants to stay compressed in quick transitions whereas Bilsteins tend to raise up due to aggressive compression damping.
            My experience is that on Koni shocks with 375/475 springs, the car was VERY comfortable with Koni shocks. It was firm but never jarring. Dare I say more compliant than stock. Compare that to the above user review of 150/435. I now have 425F/650R springs, which are pretty stiff, but I know that's just the springs. 375/475 was a dream! Moral of the story. Go Koni.

            "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."

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            • #96
              Bilstein bump stops are internal, but easy to cut down before you fit them to the car.

              As we have found they seem to be sized to run always on the bump stops even with standard springs. This is probably why people report a feeling of increased compression, although it's springing rather than damping. Damping force can't lift the car, only resist movement.

              Steve's springs are custom I believe.

              Given the terrible condition of the U.K. roads I don't think I'd want to go much more than stock rates on a road car.

              As I understand it the Bilsteins are more digressive so less harsh for sudden impact loads than Koni.....once you get the bump stops out the way...

              http://students.depaul.edu/~cmcguir1...invsKoniSA.jpg
              If everything seems under control, then you're just not going fast enough...

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              • #97
                Originally posted by caneswell View Post
                Bilstein bump stops are internal, but easy to cut down before you fit them to the car.

                As we have found they seem to be sized to run always on the bump stops even with standard springs. This is probably why people report a feeling of increased compression, although it's springing rather than damping. Damping force can't lift the car, only resist movement.

                Steve's springs are custom I believe.

                Given the terrible condition of the U.K. roads I don't think I'd want to go much more than stock rates on a road car.

                As I understand it the Bilsteins are more digressive so less harsh for sudden impact loads than Koni.....once you get the bump stops out the way...

                http://students.depaul.edu/~cmcguir1...invsKoniSA.jpg
                From my experience, the Bilsteins have more compression damping, and less rebound damping than the Konis. Also, I wouldn't lower the car at all, simply fit new dampers and call it good. If it doesn't bottom with the stock springs now, you should be ok.

                I've tried 3 different springs, and 4 different damper combos. I have finally settled with Turner J stock springs (the same as H&R Groupe N springs I think) with TC Klein revalved Koni sports. The car stands a little lower than stock, but not by much. Every other setup just blew through the travel and bottomed out over everything. Now the car drives well, a little firm, but not harsh.

                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

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                • #98
                  As stated above my springs are custom wound by Faulkner Springs in the UK. Stock ride height but 50% stiffer than stock with 24mm/16mm ARBs and Bilstein Sports with front bumpstops trimmed to 1/2 length.

                  The ride quality is great on UK roads. I noticed a greater deterioration in ride quality when going from stock top mounts to GC Touring mounts.

                  Prior to trimming the bumpstops with stock ride height the ride was hard and on inspection of the bumpstops they were clearly taking a bashing. Even at stock ride height.
                  Sport Evo No.47

                  My Sport Evo Restoration

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