To elaborate on @
cjd's post above
Quote:
Originally Posted by Bomz
No actual answers for my original question. Does anybody know why you would want the front harder than the rear as opposed to the rear being harder as designed by Toyota/Subaru?
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I am not 100% certain that these spring rates are correct but you will get the idea.
OEM Scion FR-S
Actual Front Spring Rate 2.3K
.... At the wheel 2.1k
Actual Rear Spring Rate 3.8K
......At the wheel 2.1k
OEM Subaru BRZ
Actual Front Spring Rate 2.7K
..... At the wheel 2.4k
Actual Rear Spring Rate 3.5K
.......At the wheel 2.0k
See this article for info about motion ratio
http://www.ft86club.com/forums/showthread.php?t=9936
There is no one "correct" front/rear bias. It depends on the intended use of the vehicle and driver preference.
Quote:
Originally Posted by CSG Mike
That's because if you want to be competitive, an AutoX setup and a track setup are mutually exclusive.
AutoX priorities:
- lightning fast weight shifts and small direction changes (less than 30 degrees). This is for slaloming.
-- This is achieved by REALLY high front spring rates, and a giant front sway
-- This also makes it so that under sustained cornering (sweepers), the car pushes like CRAZY, so that's why AutoX cars go deep, brake hard, and power out, rather than make a more rounded arc.
Track priorities:
- Sustained cornering speed, and being able to put power down at corner exits
-- This is achieved by getting a nice static balance.
-- Keep in mind that under power, you're unloading the front, and loading the rear.
-- Track prepped cars will sustain more raw cornering Gs, but not change direction and shift weight as quickly.
For example:
AutoX prepped FRS
- 14k/9k spring rates
- Blade type front sway, minimal rear sway
Track prepped FRS
- 10/12k spring rates
- Sways to fine tune balance.
Each car has its strengths and weaknesses. The AutoX car will likely slalom ~20% faster (raw mph), but the track prepped FRS will hold more speed on a skidpad (raw mph).
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