Street Stock Set-up, Leaf Spring (Prior to 2022)

My Firebird I built in 2016
  • Springs
    • LF: Afco 9.5", 900lb with adjustable cup
    • RF: Afco 9.5", 800lb with adjustable cup
    • LR: 225lb, Composite Leaf
    • RR: 200lb, Composite Leaf
  • Shocks
    • LF: Bilstein,197R/154C AK Digressive, Stock Location 
    • RF: Bilstein, 393R/172C AK Linear, Stock Location 
    • LR: Integra 8C/2R, PN#310-42198-2, Located rear of leaf plate
    • RR: Afco 4C/4R, 19 Series, Located front of leaf plate
  • Ride Heights
    • LF Lower ball joint center level to the center of the front lower control arm bolt (8 5/16ths" floor to center of bolt on my car with H500 tires)
    • RF Lower ball joint center 1/8th inch higher than center of the front lower control are bolt (8 1/4" floor to center of bolt on my car with H500 tires)
    • Rear ride height should place approximately 1 to 2 degrees rake in car front to rear (You can measure this on the underside of the front stub rails).
      • Raising the rear ride height by limiting lowering blocks to no more than 2 inches while using longer shackles will assist in creating forward drive because it will raise the front leaf eye location.
      • I measure and track my rear ride height by measuring floor to the center of the front eye bolt. On my car this measurement will be very close to the same as the front when I am at 2 degrees rake. It measures LR 8 5/8" and RR 8 1/2" on this setup but EVERY CAR IS DIFFERENT. Don't chase these numbers compared to yours! Lowering blocks, shackle length and how the car is built and tied together will change the front spring eye height dramatically (OK you've been warned!)
  • Weight Distribution
    • Rear Percentage of 52% is ideal. Yes, if you can get 53% the car will have more forward drive but be warned as rear percent increases you will struggle to keep the car free on exit. My experience has been at 54% or more the car pretty much refuses to turn during acceleration so I ran most of the season at slightly over 53% and lived with it being throttle tight.
    • I like 53% left side weight. I ran 54% and it works but make sure you mount all your ballast (lead) high up in the car or at 54% or more it will tie the car down and cause you to skate out in corner entry instead of transferring load to the right.
    • LR Bite / Cross Wedge are related but not the same. I focus on bite not cross because that has a much larger impact on how the car turns. On a leaf car running the softer springs on front I believe 125lbs to 175lbs is a good working range. this is one area where you have to pay attention to what the car is asking for and adjust accordingly. Every car will be different when it comes to left rear bite.
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    2 comments

    Thanks John, I am working to figure out the best way to have a go to source for Street Stock tech and reference material along with hopefully raising some funds to help us race :)

    Jason Dukes

    Jason I’m digging the new website re design this is awesome stuff brother keep on keeping on 🤙🏼💯

    John Brannen

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