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Thread: Alignment Process for the 818S

  1. #1
    Harley818's Avatar
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    Alignment Process for the 818S

    I just did my wheel alignment, and had to search through a lot of info to get ready.
    So, I thought I would put it together in one place for those who still have to align their 818S.

    Please comment if there is something that is not right. Hopefully I have it, otherwise I will have to make corrections myself.
    I never thought of doing my own alignment until I read up on the forum here that others were doing it and I just wanted to thank those who have provide info and motivation to do it myself.
    I like learning new things, so now I know how to do a wheel alignment.
    Also, I will try to give credit where it is due... and mention those I have used as a reference. Thanks to you all on the forum who have contributed.

    First, I re-read as much as I could to determine if I was ready.

    Then I pulled off all the body panels to make the alignment easier. I wanted to neaten up all the wiring and heater hoses, AWIC lines, coolant lines anyways, so this was a good opportunity to clean everything all up.
    I don’t know how easy it would be to do with panels on. Body panels off the car was really easy.

    1 - did I have the car set to ride height.... check. I had previously set mine to 5 inches. I have the yellow Koni’s that came with the 818S and Standard springs they send.

    In Xusia’s thread Freds outlined the ride height process some time ago.
    To set ride height for torquing the suspension bushings/mounts, you do not need any particular weight at all.

    - Mount your wheels with about 10 psi inflation pressure.
    - Make 4.5" or 4.75" (or whatever your target clearance number is) spacer blocks out of lumber and set them under the chassis at all four corners.
    - Adjust the spring pre load collars to absolutely no load at all.
    With the low pressure in the tires your suspension links will all be very close to ride height now.
    - Torque up all mounting hardware.
    And you are done.
    Later you merely adjust the spring pre-loads to get the car to ride height. As you add weight you tighten the collars to get the chassis up to ride height, and the suspension components to their "neutral" condition.

    2 - did I have the rear LCA mounts oriented with the "squiggle down? ....Check. (I had one upside down).
    The squiggle tang is longer than the flat tang, so this positions your LCA with more caster, and gives the most tire clearance to the firewall. Thanks to Bob and Cincy and others who noted this.
    DSCF5036.jpg
    DSCF5037.jpg
    With the body panels off, it wasn't too hard to remove the LCA, flip it over, and re-secure.
    DSCF5042.jpg
    DSCF5043.jpg

    3 - check orientation of the lower shock mount. For aluminum LCA's, this is recommended by FFR to “point outwards”, for steel LCA’s, to "point inwards”. As someone pointed out, the distance is the same for either orientation, so to many of us engineers, make your own judgement as to which orientation is right. Someone calculated stress levels to be well below failure for either orientation.
    DSCF5038.jpg

    4 - Were my trailing links set to the right length? I set them so the wheel would be in the middle of the wheel well. I checked that they were the same. I bought the adjustable ones, and they were set to 20.75 inches.

    5 - I set the rear lateral links to 15.75 per the stock subaru length. Someone on the forum mentioned they were 15.75. I have wagon links and they measure 16 1/8 centre to centre. Which is correct?

    6 - set tires on slip plates. I used two sheets of ABS plastic with grease in between. This allows the suspension to settle without residual binding due to friction with the floor. Make sure any wrenching you do doesn’t move the car. I was wondering why the jack stands moved when in fact my torquing of bolts was moving the car on the slip plates….. LOL.

    String Set up.

    You can google or youtube many versions of how to align your car with string. Hindsight and others mentioned on here that they used this technique successfully. I picked the version that sounded the most credible.

    I set up two steel angles on jack stands about mid wheel height, one in front of the car, one in back. I marked 74 inches on both angles.
    Then I measured the distance between the front angle and the rear angle to make sure they were parallel.
    I stretched some thin string on the right side marks front to back, and same for the left side marks.
    DSCF5044.jpg
    DSCF5045.jpg
    DSCF5048.jpg

    Next step is to measure from each front wheel hub to the string on each side to make sure its set at an equal distance. Slide the angle right or left until the string distance to wheel is the same both sides for the front.
    Do the same for the rear angle sliding side to side until the distance to the rear wheel hub is equal on both sides.
    The distance from the string to the wheel hub will be different front to back because of the difference in wheel track front to back. As long as they are the same for the front or same for the back you are OK.
    DSCF5046.jpg

    I re-checked to make sure the strings were still on the two marks for 74 inches on the front and rear angles, and re-checked the distance between the front and rear angles.
    You now have the strings parallel to the wheels on both sides and ready for alignment.

    The alignment I was trying to achieve was recommended by Wayne for the 818S when by tmorreta for something between the 818R and 818S. (see "front suspension alignment" thread). Hindsight also had similar numbers as his goal originally, but has changed to higher caster.
    Rear toe in 1/4 in total.
    Rear Camber -0.75 degrees
    Front toe in 3/16 total
    Front Caster 3 degrees
    Front Camber - 1 degree
    Last edited by Harley818; 05-08-2017 at 11:55 AM.
    Harley
    Bought 2002 Donor Jan 2014
    First Start Jan 18, 2015
    First Drive Feb 14, 2015

  2. #2
    Harley818's Avatar
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    I bought an AccuRemote digital gauge on Amazon for $32. Awesome tool.
    DSCF5041.jpg

    Rear Alignment
    Measuring from the strings to the rim of the wheel at the front and the back and I adjusted the front lateral link until I had 1/8 in. toe in.
    I checked the two lateral links to ensure they were level. This is important as wleehendrix and hindsight point out to the roll centre (see below for comment).
    To make them level you adjust the long trailing link…. thus adjusting the roll centre of the two links until they are level. I used my AccuRemote digital gauge on a piece of angle iron across the lateral links.
    To do the camber, you need a piece of angle vertically across the wheel rim. You can use a bolt for stand-off so it doesn’t touch the tire.
    I put the Accu remote digital gauge on the angle and adjusted camber by rotating the upper link until I achieved -0.75 degrees.
    Then checked level of the two lateral links again and if necessary adjusted the upper trailing link again to make it level. Then checked camber again and repeated.
    Rears are done!!

    Front Alignment

    I initially set the steering wheel to the centre position. I checked that it was in the centre of travel and actually had to remove the steering universal to re-set the centre.
    With the steering wheel centered, I used a similar method as the rears (measuring to the strings to the wheel rim) to set the initial toe in on the front wheels.
    I adjusted the bump steer adjustment on the tie rod and achieved a total of 3/16 in. I locked the tie rod end/bump steer sleeve.

    In adjusting the upper ball joint triangle to achieve caster and camber, I knew i would have to cut off part of the longer link, so I initially shortened the longer link as short as it would go.
    The short link gives mostly Caster but some camber as well. The long link give mainly camber but does influence caster.
    I ended up cutting approx 0.6 inches off the longer link (the threaded portion welded to the ball joint).

    Caster and Camber Right side
    Once I cut the threads on the link shorter, I made the long link as short as it would go without cutting the black adjusting nut. ‘
    Then I measured the caster by measuring the angle of the FFR element holding the balljoint. (I don’t know if this is right, but it does seem like it is parallel to a line between the top and bottom ball joints which is the definition of caster if I’m not mistaken).
    I adjusted the length of the short link until I achieved 3.6 degrees caster. (I assume the +3 to 4 degrees recommended by FFR places the lower ball joint ahead of the upper one - can someone confirm this is correct?).
    With the longer link as short as it could go, I had camber of - 0.7 degrees. To go any further I would have to cut the black nut shorter, so I figured this was a good initial setting before driving the car.
    For reference, the bolt to bolt distance for the small link was 123mm. The bolt to centre of grease nipple for the long link was 171mm. Very close to what Bob & Cincy achieved.
    I locked all the nuts and right side was done.
    DSCF5049.jpg
    DSCF5050.jpg

    Caster and Camber Left side
    I cut the threads for the long side the same amount 0.6 in.
    Initially I had trouble getting this side right. A small change in the small link really changed the camber, and changes to the large link affected the caster.
    So I made smaller changes, and gradually got it set right.
    I ended up with 3.5 degrees of caster, and camber of -0.7 degrees
    DSCF5051.jpg
    DSCF5052.jpg

    However, the links are not the same as the Right side.
    The small link bolt to bolt is 125 mm. The bolt to centre of grease nipple for the long link was 177mm.
    Within 2mm on the short link, and within 7mm on the longer link.
    I don’t know why it would be different, but perhaps slight changes in the mounting of the rear LCA bushing?

    Again, once I secured all the locknuts, I re-checked the caster, camber and toe in. All good.

    In the end I didn’t quite get the numbers that Wayne recommended, but then again, its a guideline and I’ll have to try it out.


    I hope this will be helpful to those who still need to do their alignment.
    If you have any suggestions to improve this let me know and I’ll edit it.
    Harley
    Bought 2002 Donor Jan 2014
    First Start Jan 18, 2015
    First Drive Feb 14, 2015

  3. #3
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    This is good. Thanks for posting. Sticky?

  4. #4
    Harley818's Avatar
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    Hindsight just responded to me on this with comments which I will past here so its all in one place.
    He makes some good points.....

    Harley, your write-up looked pretty good. The only thing I will say is that after buying and using a bump-steer gauge to check my bump steer, I found that even with the rear links parallel, I still had some bump out. You want zero bump, or some bump IN, but never out. Theoretically, if the rear links are exactly parallel, you are probably very close, but to play it safe, I would actually adjust them so the rear link is lower than the front link.... not much.... a tiny amount. This guarantees you'll have some bump-in which is safer than bump out. If you have a bump-steer gauge, use that instead.

    I'm not sure about your caster method. Theoretically it could work but when I tried that method, I got a different number vs the method that an alignment shop would use so I went with the method where you check camber with the wheel out 15 degrees, zero out the digital gauge, then turn the wheel back to 0 then 15 degrees the other way and check camber again. The number you see is the true camber. It's a pain to do if you don't have turn plates but with some cardboard, tape, protractor, and sharpie, you can make it happen. I've done it twice now.

    I also noted some slight differences from left front to right front. I attributed it to drift in the frame caused during welding by FFR.

    Your string alignment procedure looked good. Very important that the strings are exactly the same width front to rear. You used angle, I used conduit. One thing about string alignment is that the alignment specs are supposed to be taken from the outside of the tire, where the tread is, in the center. If you take it from the rim, you are going to end up with more actual toe-in than you are seeing on your measure (the further out you go, the more you get). I did the math (triangle basically) and found that on 235/40/17, measuring from the rim gets you 1/3 less of the actual toe. Meaning, if you measure 1" of toe at the rim, it would be 1.33" at the tire (using large number to make example more clear). Also, the order of operations should be camber, caster, toe, bump. If you do bump, you may want to re-check toe afterwards. Cant remember if you specified that in your write-up or not.

    Sorry, can't answer your trailing arm length question. I put my OEM ones on the bunch and marked center to center, measured it, then duplicated it on my aftermarket arms. I MIGHT have listed the length in my build thread but can't remember. Might just post a new thread asking for someone who still has their rear trailing arms off the car to measure them for you.


    Based on Hindsights comments, I'm going to re-do and check caster by his method using my greasy slip plates, and re-do the toe in at the tire tread diameter rather than the wheel. In effect, if I thought I had 1/8 toe in at the wheel, it will be about 30% more at the tread..... to much.

    Anyone got the correct length for the lateral links???
    Last edited by Harley818; 05-09-2017 at 12:06 AM.
    Harley
    Bought 2002 Donor Jan 2014
    First Start Jan 18, 2015
    First Drive Feb 14, 2015

  5. #5
    Senior Member RM1SepEx's Avatar
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    Lower trailing arm, 20 5/8" these are the only suspension parts sitting on my unused parts shelf...
    Dan

    818S #17 Picked up 8/1/13 First start 11/1/13 Go Kart 3/28/14

  6. #6
    Moonlight Performance
    Hindsight's Avatar
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    Harley, I should have been more clear on the tread vs rim measurement. Don't worry about re-doing it and measuring from the tread. It's very hard to get an accurate measurement on the tread. Instead, just use math to determine what the measurement from the tread would be (IE add 1/3 to your measurements).

  7. #7
    Harley818's Avatar
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    Quote Originally Posted by RM1SepEx View Post
    Lower trailing arm, 20 5/8" these are the only suspension parts sitting on my unused parts shelf...
    Thanks Dan, but I'm looking for the lateral links length.
    Harley
    Bought 2002 Donor Jan 2014
    First Start Jan 18, 2015
    First Drive Feb 14, 2015

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