Proper way to scale car?
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Launching!
Joined: Mar 2002
Posts: 229
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From: Amarillo
Proper way to scale car? With racing season upon us I’m trying to find a write up or tutorials on how to scale my 99 twin turbo drag car. Car has Afco coilovers. What is recommended for rear weight left to right? Bias distribution recommended? Do you add weight to the car to get proper bias, etc.? When scaling do you worry about the ride height being even all around or just the weight distribution? Any help would be much appreciated.
Thanks
chris
Thanks
chris
Driver in the car on level ground. Want about 75-100 lbs on rr more than left, depending on anti rollbar stiffness and power. Unhook sway bar to scale, reinstall sway bar with zero preload.
front to rear start around 53 pct front see what that gets you unless it’s making big power then 55 plus,
try to scale front as even as you can, left front will always (normally) be heavier due to right rear having more weight on it, this is ok.
set ride height first, the adjust shocks, ride height will change depending on where the weight needs to be. Leave it once it’s there.
make sure shock travel is where you want it as well. Depending on slick or radial and what type of conditions you will see will change that.
hope that helps
front to rear start around 53 pct front see what that gets you unless it’s making big power then 55 plus,
try to scale front as even as you can, left front will always (normally) be heavier due to right rear having more weight on it, this is ok.
set ride height first, the adjust shocks, ride height will change depending on where the weight needs to be. Leave it once it’s there.
make sure shock travel is where you want it as well. Depending on slick or radial and what type of conditions you will see will change that.
hope that helps
When you launch the driver front rises and puts a ton more force on the pass rear So having a naturally pass rear heavy situation when the car is level, will result in an overly heavy pass rear setup when the car is in motion during a launch. This is especially true if the car is not super stiff. My driver side wheel will lift a good 6-7 inches before the pass side lifts.
Guess what I'm saying is it's vehicle specific. IMO you should try to get the car level weight wise or as close to it as possible when it's stationary. Adjust suspension from there as needed to make it work. Without having the weight on wheels values for the car as its launching.... I don't see how one could ever calculate the perfect corner weights for a drag car launch?
In my situation I dialed in the car and what worked, then corner weighed. With the car setup balanced across the rear the car drove left hard. I had to drop weight from the pass rear to go straight. Which could be from a crooked chassis or 100 other reasons... Each car will differ in my experience.
Just my take...,
Guess what I'm saying is it's vehicle specific. IMO you should try to get the car level weight wise or as close to it as possible when it's stationary. Adjust suspension from there as needed to make it work. Without having the weight on wheels values for the car as its launching.... I don't see how one could ever calculate the perfect corner weights for a drag car launch?
In my situation I dialed in the car and what worked, then corner weighed. With the car setup balanced across the rear the car drove left hard. I had to drop weight from the pass rear to go straight. Which could be from a crooked chassis or 100 other reasons... Each car will differ in my experience.
Just my take...,
Last edited by Forcefed86; Apr 10, 2020 at 08:47 AM.
