noogie
Well-Known Member
- Thread starter
- #1
This thread will be used to discuss suspension frequency theories.
Common suspension frequencies:
To calculate the GR Supra's factory suspension frequency, you'll need the motion ratio, corner weight, and spring rate.
Calculator:
http://farnorthracing.com/autocross_secrets16.html
Factory spring rates:
Front: 168 lbs/in; 3.0 kg/mm
Rear: 515 lbs/inch; 9.2 kg/mm
Motion ratio:
1 / lever ratio = motion ratio
Front: 1 / 1.18 = 0.85
Rear: 1 / 1.69 = 0.59
source: https://www.hks-power.co.jp/en/product_db/hipermax/db/31743
Corner sprung weight:
Corner weight - unsprung weight
Front: 395 kg - 45 kg = 350 kg
Rear: 367 kg - 50 kg = 317 kg
Note: the unsprung weight is an estimate. 45kg and 50kg are rule of thumb with the higher number on the drive axle.
This gives you a factory suspension of about:
Front: 1.2 Hz
Rear: 1.51 Hz
Common suspension frequencies:
- 1.0 Hz - passenger cars
- 1.25 to 1.75 Hz - sports cars
- 2.0 to 2.5 Hz - autocross and racecars with low downforce
- 2.5+ Hz - high downforce racecars
To calculate the GR Supra's factory suspension frequency, you'll need the motion ratio, corner weight, and spring rate.
Calculator:
http://farnorthracing.com/autocross_secrets16.html
Factory spring rates:
Front: 168 lbs/in; 3.0 kg/mm
Rear: 515 lbs/inch; 9.2 kg/mm
Motion ratio:
1 / lever ratio = motion ratio
Front: 1 / 1.18 = 0.85
Rear: 1 / 1.69 = 0.59
source: https://www.hks-power.co.jp/en/product_db/hipermax/db/31743
Corner sprung weight:
Corner weight - unsprung weight
Front: 395 kg - 45 kg = 350 kg
Rear: 367 kg - 50 kg = 317 kg
Note: the unsprung weight is an estimate. 45kg and 50kg are rule of thumb with the higher number on the drive axle.
This gives you a factory suspension of about:
Front: 1.2 Hz
Rear: 1.51 Hz
Sponsored
Last edited: