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  • Alignments and ride-height

    I recently finished a full overhaul of my car's suspension, and will be having it aligned on Thursday...after doing some searching I was surprised that there haven't been threads in the past discussing alignment specs.

    My car is going to be used for track days and fun-drives, but not much commuting, so I feel I can get away with a more track-oriented setup and not worry too much about excessive camber/toe wear on the street.

    I did find the stock specs in a post, which are:

    Front camber: min. -1.20°, nomimal -0.70°, max -0.20°
    Front caster: min 8.63°, nom 9.13°, max 9.63°
    Front toe: min 0.10°, nom 0.14°, max 0.18°
    Front cross camber: min -0.50°, nom 0.00°, max 0.50°
    Front cross caster: min -0.50°, nom 0.00°, max 0.50°
    Front total toe: min 0.20°, nom 0.28°, max 0.37°
    Rear camber: min -2.83°, nom -2.33°, max -1.83°
    Rear toe: min 0.18°, nom 0.23°, max 0.29°
    Rear total toe: min 0.35°, nom 0.47°, max 0.58°

    So far, what I've decided to start with is:

    Front camber: -2.5°
    Front caster: 9.25°
    Front toe: 0°, or a little toe-out, 0.25° maximum total toe-out

    Rear camber: -2.5°
    Rear toe: As close to 0° as I can get it, or a little toe-in, 0.5°maximum total toe-in

    My reasoning:
    I feel that zero toe or a little toe-out in the front will help with turn-in, with the trade-off of reduced high-speed stability. Best to err on the side of toe-in on the rear, to keep things in check at that end. I doubt I will be able to get zero toe in the rear anyways, but it's something to aim for. Front caster will remain within the stock range, I don't want to cut my strut towers to get any more adjustment. Rear camber only slightly more negative than stock, but significantly more front camber than stock to compensate for the MacPherson-strut geometry.

    Unfortunately I will not be able to cornerweight the car before having it aligned, however I will probably buy a set of scales over winter, and redo everything in the springtime after I play around and learn what works and what doesn't (for my always-changing driving style).

    Front ride-height will be whatever results in level control arms. Rear ride-height I'm not sure where to set...

    In the front I am running 440lb/in front springs in shortened/reinforced front struts with GC Koni SA's. GC Camber/caster plates. E36 M3 control arms with treehouse solid offset bushings. Stock front swaybar, with adjustable links.

    In the rear I have 660lb/in springs (one was marked 657lb/in, the other 663lb/in. I put the slightly stiffer spring in the passenger rear, figuring the LF/RR crossweight will be the heavier of the two if they are not equal). Koni SA's, and stock rear swaybar. Poly subframe/trailing arm bushings, with welded-in eccentrics.

    Ok, despite all the numbers and rambling, what I'm actually trying to ask is:"what has worked for you guys?"...and hopefully the full disclosure of my setup will help more experienced owners give their input.
    I am pretty confident about my initial numbers, except for the camber settings. The front camber I will be able to play with quite easily and return back to spec if things go horribly wrong, but the rear is something I would like to get in a good ballpark and not feel the need to tweak.

    -Nick

  • #2
    When running soft springs, you need as much camber as possible in the front, but not at the back. If you lower the car a lot, chances are that you will end up with way too much rear camber and toe. Inside tire temps will be very high, meanin g the tire is not using properly its contact patch. If you check your tire temps you will see what I mean. There are three ways around. Raise the rear. Use camber adjusters. Raise the subframe by 12mm. Start by raising the rear subframe and then try adjusters. Obviously, always monitor tire temps at every change.


    [email protected]

    1969 2002 racecar
    1989 M3 racecar
    e39 Touring

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    • #3
      Hi Lee,

      Thanks for the post ...I am familiar with what to look for when making changes to an alignment (regarding tire temps across the contact patch), however I was hoping people would be able to chime in what ACTUAL specs has worked for them. I already have the means to adjust the rear camber and toe, and was just trying to skip some of the guesswork when getting the car aligned for the first time.

      You mentioned raising the rear subframe on your friend's car helped quite a bit. Do you know what the actual rear camber was after making the change, and its relation to the front camber? I know the alignment requirements will vary from track to track, but in a general sense there will be a ratio of front/rear camber that works 'best' for a chassis with certain roll-rates. I guess I will be finding out the 'trial-and-error' way

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      • #4
        Nick,
        Sorry I don't have my alignment spec sheet with me at work to give you exact numbers, but I get my car aligned at a local BMW dealer who has a tech on staff who is also a racer. He generally starts with the specs in the data base for an Evo3 and modifies it from there depending on tires and personal preferences. Some guys like a happy tail, some don't. I can say that in my car, with my suspension, 0 rear toe makes for a really tail happy car under power, in the rain...forget about getting on the power in a turn. I have chosen to go with a bit more rear toe in and front tow out. Again, this is my personal taste. Like Lee stated, too much drop in the rear results in way too much neg camber, in fact lowering the car too much with stock pickup points will cause all kinds of geometry problems, so I have chosen to go quite a bit lower that stock, but not slammed to the ground.
        I guess the bottom line is that regardless of what works for me or Lee, you'll eventually have to develop your set up for what feels good to you. I don't think there are any magic answers on this one.
        Jeff






        NASA GTS5 #945
        NASA GTS5 Midwest Regional Champion ('09,'11,'12 & '14)

        Comment


        • #5
          I am pretty sure my specs are as follows:

          Rear:

          Toe in.1/6
          Camber -2.3

          Front
          Toe 0
          Camber -3.5
          Caster is max about 9.5

          My set up is:

          Front spings 500
          Rear springs 700

          Koni SA:
          Front 1/4 turn off full stiff
          Rear 1/2-3/4 turn off full stiff.

          IE Bars set at full soft up front and almost full soft in the rear. No pre-load. They are the next things I am going to change as I feel I do not need this much bar in the car. I run 235/40/17 on M5 wheels. The car handles great but I am always looking for more.

          Best,

          Jordan
          Last edited by jordantii; 09-27-2006, 05:20 AM.
          "Never lift"

          Comment


          • #6
            Hey guys, thanks for the info. Seems like the baseline guess-timate in my first post should be a good place to start, although I'll probably start with a little more negative camber in the front...now it's time to shop for a good pyrometer and the tweaking fun will begin.

            Comment


            • #7
              Yeah Nick, you seem to have it under control. I think you specs are good, for sure they are in the ball park. I would also say that 2.5 in the rear is the most you want to run. I am a little less and it is fine.

              Jordan
              "Never lift"

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              • #8
                "I recently finished a full overhaul of my car's suspension, and will be having it aligned on Thursday...after doing some searching I was surprised that there haven't been threads in the past discussing alignment specs."

                Good point... I don't remember my specs... the thing is they can go out once you hit a pothole.... I think you would be amazed at when you align the car, get off the alignment rack, and go back on, the numbers change...

                I just go out there and drive and learn...

                Comment


                • #9
                  True, an alignment can go out of whack with a big shunt or pothole, but considering a bad alignment can destroy an otherwise well-sorted car's handling, I think it's still something that needs to be taken into account. I did a full season of autocrossing and a hillclimb all on my homejob eye-balled alignment on my old GTI, so I figure I should treat this car to the fancy equipment

                  The car is all aligned now, and first impressions are very good Can't wait to do a trackday.

                  Comment


                  • #10
                    Nick,

                    I was looking at your thread and I imagine you were able to sort out your alignment already. I'm in the same problem you were in 2006 and wanted to know how did you end up. I am running stock suspension, rt-615 tires and last time in the track used -1.5 both front and rear. Car was very good but still with more temperature on the outer edge of the tires, specially at the front, meaning I can still need to increase negative camber. I want to go more agressive now and was thinking on steping to -2.5 or -3 front and -2 rear. I do not have many chances to try different setups reason why I need to go to the track next time with the closer to perfect possible, Any suggestion?
                    1987 E30 M3
                    1992 E36 325i (race car)
                    1983 E24 635csi (for restoration)

                    Comment


                    • #11
                      Originally posted by aemotorsport View Post
                      Nick,

                      I was looking at your thread and I imagine you were able to sort out your alignment already. I'm in the same problem you were in 2006 and wanted to know how did you end up. I am running stock suspension, rt-615 tires and last time in the track used -1.5 both front and rear. Car was very good but still with more temperature on the outer edge of the tires, specially at the front, meaning I can still need to increase negative camber. I want to go more agressive now and was thinking on steping to -2.5 or -3 front and -2 rear. I do not have many chances to try different setups reason why I need to go to the track next time with the closer to perfect possible, Any suggestion?
                      I would definately go to -2.5 front and stay where you are or go -2 rear.
                      Cheers,
                      John
                      88M3 henna


                      73T100C
                      97 540\6-Gone
                      2008 MINI Clubman S

                      Comment


                      • #12
                        Originally posted by aemotorsport View Post
                        Nick,

                        I was looking at your thread and I imagine you were able to sort out your alignment already. I'm in the same problem you were in 2006 and wanted to know how did you end up. I am running stock suspension, rt-615 tires and last time in the track used -1.5 both front and rear. Car was very good but still with more temperature on the outer edge of the tires, specially at the front, meaning I can still need to increase negative camber. I want to go more agressive now and was thinking on steping to -2.5 or -3 front and -2 rear. I do not have many chances to try different setups reason why I need to go to the track next time with the closer to perfect possible, Any suggestion?
                        Like John mentioned, -2.5° front & -2° rear is probably a good place to start. With stock suspension though, what methods do you have to alter your camber front and rear?

                        The alignment I ended up with after my original post turned out to be ok...not exactly what I was expecting, but it was a good start...Keep in mind that I'm not running stock springs or dampers, but it started-off like this:
                        Front camber: -3.1°
                        Front caster: 9.75°
                        Front toe: 1/16" total toe in (1/32" per side). (stupid readout doesn't report toe in an angle measurement...)
                        Rear camber: -2°
                        Rear toe: 3/16" total toe in (3/32" per side).

                        When I had the alignment done, my rideheights were a bit out of wack. I hadn't found too much info on rideheights, so I just left it at my 'eyeball' measurements of what looked reasonable. It had a fair amount of rake, with the rear of the car sitting a bit high.
                        With that alignment, the car felt good, but the front end felt a bit washy after turning in, and on corner-exits (so basically 2/3'rds of every corner :P ). Camber-wise it was evident from tire temps and wear that the front camber was a bit excessive.

                        Since that alignment, I have raised the front rideheight slightly, fabricated some 1" rollcenter spacers for the front struts, and lowered the rear rideheight somewhat significantly. I have not re-measured what the resulting alignment is, however the 'typical' effects of changing the rideheights like I did would be: less front camber (due to raising the front end), more rear camber, and more rear toe-in (due to lowering the rear end). I can't find what my rideheight #'s are at the moment... I also did some more fiddling with the shocks (Koni SA's).

                        After making those changes, I (subjectively) found that the car has a bit more corner exit bite (although I still feel I should back off the front camber a bit, to somewhere around -2.5°)...I'd still like to re-align it and will probably do so when I re-insure my car for this year and get some regular maintenance things out of the way.

                        Sorry for the long-winded post, I hope there is something useful in there :P
                        -Nick
                        Last edited by NickS; 03-09-2008, 06:48 PM.

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                        • #13
                          Version:1.0 StartHTML:0000000149 EndHTML:0000001371 StartFragment:0000000199 EndFragment:0000001337 StartSelection:0000000199 EndSelection:0000001337 I had my car’s alignment checked today because it was pulling to the right. Ultimately it wasn’t with the alignment, so is likely something with the tires. My E30 M3 is significantly lowered and setup for mainly the track (but I do drive it on the street once a week). It has Ground Control fully adjustable suspension.

                          I searched around and this is the only thread I found that described other folks setup (most threads are focused on installing GC/coilovers to get the car as low as possible rather than on having a great all around track/street setup).

                          Here is my current setup:

                          FRONT

                          * Camber: -3.3
                          * Caster: 10.11
                          * Toe: 0.0

                          REAR

                          * Camber: -4
                          * Toe: 0.07 (0.12 left, -0.05 right)

                          I don’t have ride height numbers, but I raised it slightly a while back since it was frequently touching pavement over speed bumps. I am ok with chewing through some tires, but might raise it a bit to lessen the camber a bit. Any thoughts?

                          Front springs are 450, rear are 625. I need to check my Koni SA current position, these were adjusted before I bought the car and I haven't checked since. Any suggestions on that front?

                          '89 E30 M3
                          (Diamondschwarz) | '01 E39 M5 (Silbermetallic)

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                          • #14
                            Front: Camber -2.5 Toe:0.0 Caster: 9.5 (from memory) Rear Camber -2.0 Toe: 3/16" Total Toe in Koni SA 1/4 turn from full stiff front 1/2 turn from full stiff rear ST bars Front: soft Rear: Just above full soft. H&R race springs
                            1989 e30 m3 Zinnoberrot/Grey 256k Track/M3T
                            1991 e30 m3 Alpinweiß/Schwartz 81k Garage Queen
                            1991 325iX Diamantschwarz/M-Tech 110k Snowmobile (For Sale)
                            1991 325ic Macau Blau/M-Tech 178k M-Tech Cabrio 5spd (For Sale)
                            2002 Chevy 2500HD 8.1 Vortec, Alison Tranny, 4.10 gears

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                            • #15
                              FRONT

                              * Camber: -2.3°
                              * Caster: 9.5° (stock-ish)
                              * Toe: 0.0mm
                              wheelcenter to fender 330mm
                              spring 60 N/mm
                              ARB IE 25mm E30 links, pos. soft

                              REAR

                              * Camber: -2.3°
                              * Toe: in 1.5mm
                              wheelcenter to fender 310mm
                              spring 100 N/mm
                              ARB IE 22mm , pos. soft-20mm

                              Here's my current street/track setup (track: optional increase front camber to -2.8° ARBs front med, rear med)

                              HTH
                              Thomas
                              sigpic

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