Front end alignment at home

Discussion in 'How To Forum' started by Hermes, Nov 1, 2015.

  1. Hermes

    Hermes TMO Advanced

    Messages:
    193
    Likes Received:
    20
    Joined:
    Jun 12, 2012
    Location:
    Rochester, NY
    Took me a while to get around to writing this up, but I've been aligning my front end at home before and after each track event for the last couple of years. I drive my Boss just about every day I can in the summer so I do this in order to extend the life of my street tires. I've been setting my street alignment at -0.75 camber and 1/16" toe in [which I don't really adjust, but will explain later].

    Alignment tools:
    A friend of mine who got out of racing gave me a Maximum Motorsports camber gauge [bubble type, it works great] and Longacre tape toe plates. I also use a square.

    [​IMG]

    Step 1: Find or create a flat surface
    My first step was to see if my garage floor was flat, which it wasn't. I marked a spot in the garage and checked camber with the car nose in. I then backed the car in with the tire on the same spot and checked camber again. The difference in the reading was due to a tilted floor. I played around with different combinations and thicknesses of some scrap plywood until I got even readings. I then moved that plywood to a deeper spot in the garage just to be able to have the entire car fit in and checked that I had the same reading. I painted the outline of the plywood on the floor and this is now a known position and plywood that I use every time.

    [​IMG]

    Step 2: Confirm accuracy of toe plates

    Initial toe measurement: I only did this once to give me confidence in the Longacre toe plates. I took 2 jack stands looped a string line around one stand and tied it to the other stand.
    [​IMG]
    I set the line height through the rough center of the hub.
    [​IMG]
    I positioned the jack stands until I got the reading between the line and the rear of the rear wheel to be the same as to the front of the wheel. At this point I established the line is parallel to the rear wheel axis. I then measured line to front and rear of the front wheel. I had to do both sides at one time since there was a chance that my reading could be affected by my steering angle. It was off so it took me a couple of tries adjusting the steering wheel until the left toe and the right toe were the same.
    [​IMG]

    I now checked the toe using the toe plates and noted they were about as close as I could read to 1/16"
    [​IMG]

    Step 4: Measure camber
    My camber gauge is older and isn't big enough for 18 or 19" wheels, so I use a square and offset my measurement from the center of the wheel. It's good to use a square anyway to make sure that the top and bottom contact points between the gauge and the wheel is vertical [or plumb]. This gauge requires you to count the number of turns and interpolate between graduations at 1/8 degree, but it is very repeatable and does not need to be calibrated before use. I tried a cheap Harbor Freight angle finder, but had really bad results.

    [​IMG]

    Step 5: Measure toe
    The toe plates are pretty straight forward to use. I made sure I labeled the plates left and right and the tape measures front and rear to get more consistent results. I also placed a mark at the center of each plate and line that up with the hub. It's important to make sure you use even tension when pulling on the tape, I do that just by feel and pull both at the same time.

    [​IMG]

    Step 6: Determine repeatability
    I made an appointment at my Ford dealer to get my front end aligned and set my camber to -2.25. I checked my camber and toe every day when I got home for about a week and a half. I realized that I got the same readings giving me confidence in my ability to measure camber and toe.

    Step 7: Determine accuracy
    I took the car to my Ford Dealer who has a Hunter laser alignment set up and spoke with the mechanic about what I was doing. I told him that I had set my alignment for the track and wanted him to give me a print out to compare with my measurements, then I asked him to set the camber at -0.75 adjust the toe and give me another print out for the street set up. This gave me 2 data points to compare. I found that my track set up measurements were within 0.05 deg of the Ford measurement. I then measured the car at home and got identical measurement to the Ford measured street set up.

    OK so at this point I've established that the toe plate measurements are very close to what I measured with the longer string procedure, I verified that the floor surface [with plywood shim] is flat, I checked that I get the same reading day after day, and I compared my readings to a known reading from Ford to check that I'm accurate.

    Now here is what I do before and after each track event:
    1. jack car up - I usually take advantage of this while I'm changing between track and street brake pads
    2. adjust camber plates - I have the MM plates and have marks that get me really really close to either my street of track set up. For people who've never done this before, you need to have both front wheels unloaded to move the camber plates otherwise you'll be working against the sway bar load.
    3. settle the suspension - I will back the car straight back and brake hard, the go forward braking hard a couple of times while rolling back onto my floor leveling spacer
    4. measure camber
    5. repeat until camber comes in, this never took me more than 4 tries and now usually 1 or 2 tries
    6. once camber is set on both sides, I check toe

    That's it, I have never adjusted toe. I go over a pretty big camber range at -2.25 track and - 0.75 street and find that toe changes from about 1/16" toe in street to about 0 - 1/32" toe out track. Since these numbers work for me, I never adjusted these. I only have 10k miles on my street tires so it's too early to tell how well they will wear at -0.75, but my Pirelli's wore pretty unevenly at the factory -1.5. By the way my caster is at max negative which was measured to be -7 deg and I never adjust it.

    Hope this is useful, I may have forgotten on been unclear about certain steps so let me know if anyone has any questions or comments on how to do this better.
     
  2. VoodooBoss

    VoodooBoss Rick Moderator

    Messages:
    19,663
    Likes Received:
    2,137
    Joined:
    Nov 30, 2010
    Location:
    90 Miles East of Sonoma Raceway
    Excellent! Thanks for posting.
     
  3. TMSBOSS

    TMSBOSS TMO Addict

    Messages:
    3,502
    Likes Received:
    739
    Joined:
    Aug 23, 2011
    Location:
    Illinois
    Oh Yea. Very useful!!

    I have the same camber gauge. Will use this technique.

    Thanks!!
     
  4. quimuel17

    quimuel17 TMO Intermediate

    Messages:
    10
    Likes Received:
    2
    Joined:
    Nov 20, 2017
    Location:
    Santa Clara, CA
    It would be great if you have a DIY video as well. I like how thorough your method since I'll be needing this information after I installed my set of Toyo street tires to try on.
     
  5. Norm Peterson

    Norm Peterson Corner Barstool Sitter

    Messages:
    266
    Likes Received:
    226
    Joined:
    Oct 22, 2017
    Location:
    a few miles east of Philly
    Just a couple of quick comments,

    It sucks what P-bucket has done to this thread.

    You should not assume that rear toe is zero even with a stick-axle car (I've seen over 0.25° "in" on both rear wheels on a solid axle before). Best to check string parallelism more directly (in front of and behind the car).

    Side to side "levelness" of your setup area can deviate from perfectly horizontal if you're willing to work however much slope into your camber measurements as a "correction". Side to side setup pad height differences of 1/16" over a 60+ inch track dimension probably aren't worth obsessing over (around 0.06°, adds to one side's measured camber, subtracts from the other side's). Small front to rear slopes are even less important unless you're also going to be checking and adjusting caster.

    -0.75° camber is very mild for even a "regular GT" (it's the factory-preferred setting for every not-used-for-corner-carving early S197), and 1/16" toe in is about twice as much "in" as you need even for street-only driving. My thoughts here are that you need to consider how "enthusiastic" - on average - your cornering tends to be. Just that I don't see a need for quite so much difference between street and track when track is only a little more negative than -2°. Besides, less camber variation will bring the amount of accompanying toe variation down.

    Digital angle finders such as the ones available at Harbor Freight are entirely good enough (0.1° resolution). Worst case, you might want to attach a length of aluminum angle so it'll reach across the full diameter of larger wheels (even though anywhere across the wheels will give you the same measurement as long as the wheel isn't bent and you make sure to hold the angle finder vertical as seen in side view to the car).

    [​IMG]

    There are even lower-tech approaches that actually work acceptably well.

    [​IMG]

    And if you're so inclined, you can even build your own gauge that has better than 0.1° resolution.

    [​IMG]


    I've been doing all my own alignments since the early 1980's. Without making any of the tire companies needlessly more profitable.

    If it matters at all, my '08 GT is currently running about -1.9° cambers. Not much more than it always did, actually.


    Norm
     
    Last edited: Dec 23, 2017
    TymeSlayer and RES_22 like this.

Share This Page