How much drop is too much

Discussion in 'Technical' started by Ivan Colesnic, Dec 31, 2015.

  1. Ivan Colesnic

    Ivan Colesnic Member

    Joined:
    May 18, 2015
    Messages:
    91
    Likes Received:
    13
    Trophy Points:
    25
    Vehicle:
    1973 Ford Maverick
    Hey guys, so I figured out my woes. Going with SPC 94210 upper control arms, moog r series lower control arms, kyb shocks, belltech springs, scott drake spring perches. Going to weld in new brackets for the sway bar and going 1-1-1/8" inch.

    So my question is for those of you that have done the Shelby drop or have the SPC control arms, how much drop in ride height did it give you if any? Some guys installing them on YouTube said it drops the car 1 5/8" inches, is that true? I planned on putting 1" drop spring too, so that would give me 2 5/8" drop. Seems like too much, especially with 18 inch wheels which is what my brakes require.
     
  2. jasonwthompson

    jasonwthompson Member

    Joined:
    Mar 25, 2012
    Messages:
    1,377
    Likes Received:
    475
    Trophy Points:
    196
    Location:
    Carrollton TX
    Vehicle:
    72 Comet
    I just got a pair of the SPC 94210's but have not yet installed them. If I get them done before you I will post the results. My feeling is that no reduction in spring height will be necessary.
     
  3. groberts101

    groberts101 Member

    Joined:
    Apr 22, 2007
    Messages:
    4,166
    Likes Received:
    535
    Trophy Points:
    297
    Garage:
    1
    Location:
    Minneapolis, MN
    Vehicle:
    1971 Comet GT
    I've done 2" arning arm drops(needs negative wedges to avoid balljoint bind) and the most I have ever seen in ride height reduction is around 1 1/4" at most. The typical 3/4" drop will give you about a 3/8"-7/16" of ride height drop. They guys talking major height drops are either exaggerating or simply mistaken.

    As far as stacking all those parts together?.. it's always easier to take a half coil out of the equation than add it back in when things end up too low for your taste.

    I plan on using the SPC arms and adding a lighter 1/2" - 3/4" arning drop.
     
  4. jasonwthompson

    jasonwthompson Member

    Joined:
    Mar 25, 2012
    Messages:
    1,377
    Likes Received:
    475
    Trophy Points:
    196
    Location:
    Carrollton TX
    Vehicle:
    72 Comet
    So I just finished installing the SPC 94210 upper control arms and got the car aligned. The SPC arms have a 1 inch drop incorporated into the shaft as well as 2 degrees of caster. Before touching the car it was 28 inches from ground up to the bottom of the fender measuring straight up through the wheel centerline. Now it is 27.5 inches, so in my case a 1 inch drop resulted in a half inch difference in ride height.
     
  5. mojo

    mojo "Everett"- Senior Citizen Supporting Member

    Joined:
    Jul 20, 2009
    Messages:
    5,274
    Likes Received:
    833
    Trophy Points:
    513
    Garage:
    1
    Location:
    Chicago
    Vehicle:
    73 Comet GT-302 4bl
    So, what difference do u notice in ride/handling w/ the new setup? Did U change any other suspension/steering components?
     
  6. jasonwthompson

    jasonwthompson Member

    Joined:
    Mar 25, 2012
    Messages:
    1,377
    Likes Received:
    475
    Trophy Points:
    196
    Location:
    Carrollton TX
    Vehicle:
    72 Comet
    Everything is the same with the exception of the upper arms. There are 3 main things I noticed immediately.

    1. The car seems to take road imperfections, pot holes, cracks, bumps, uneven pavement, more gracefully. Before when you ran over these things it was like the car was dropped from a helicopter, while traveling at 45 mph, and two feet off the ground. After the initial jarring, the car went one way and the steering went another. Now the car seems to grip the road contours. I suspect that this is due to the use of bearings in the upper control arms instead of bushings. I think the suspension is better able to articulate and compensate for road imperfections. It feels more like a roller coaster ride than a wagon ride.

    2. It feels much more stable at highway speeds. Previously, above 50 mph it was a wrestling match with the steering wheel to keep the car in a straight line, and often it was unclear as to whom was winning the match. I think this may be due to the built in 2 degrees of caster.

    3. The car is more level in turns. Before, the body roll, particularly in higher speed turns, was so great I thought the side view mirrors were about to fly off as they scraped the pavement. There is still some roll, but it is marginal compared to what it was. I suspect that if I were to upsize the anti-sway bar from what the factory put in, it would really hug and hold the corners. This is probably due to the 1 inch drop incorporated into the upper arm.

    One of the things I am contemplating next is roller bearing spring perches, and/or larger anti-sway bar.
     
  7. groberts101

    groberts101 Member

    Joined:
    Apr 22, 2007
    Messages:
    4,166
    Likes Received:
    535
    Trophy Points:
    297
    Garage:
    1
    Location:
    Minneapolis, MN
    Vehicle:
    1971 Comet GT
    Even though you'll eventually hit the point of diminishing return.. don't forget to use the shims they gave you to hit that 3°+ mark if at all possible. Strut rod can also be used for that last little bit but just keep in mind that very heavy caster(not that you'll get there in this case) will start to accelerate wear and tear on bushings/steering components and the hydraulics of PS equipped cars.

    Out of curiosity, what size front tires do you have?

    And what alignment spec's have you dialed in so far?

    oh.. and thanks for the feedback on the arms. Much appreciated.
     
  8. jasonwthompson

    jasonwthompson Member

    Joined:
    Mar 25, 2012
    Messages:
    1,377
    Likes Received:
    475
    Trophy Points:
    196
    Location:
    Carrollton TX
    Vehicle:
    72 Comet
    The fronts are 225/60 15. The specs I believe are +2.0 caster, 0 camber and 1/8th toe, but I think one side was 1.9 caster.
     
  9. groberts101

    groberts101 Member

    Joined:
    Apr 22, 2007
    Messages:
    4,166
    Likes Received:
    535
    Trophy Points:
    297
    Garage:
    1
    Location:
    Minneapolis, MN
    Vehicle:
    1971 Comet GT
    Cool. Not a huge tire.. but a bit on the round side.. maybe try adding a bit of camber next time. Will help control/counteract the sidewall flex a bit better in the twisties.

    And maybe it's a done deal for now.. but don't be afraid to get that caster up near or even beyond 3 degrees next time. It will add more icing to that $400 upper a-arm cake you just bought. Can't hardly wait to hammer mine around town with those arms this year. Many tower mods in my cars future and hoping to get up near 5 degrees caster once all is said and done.
     

Share This Page