View Full Version : Importance of front sway bar angle?
Brian76
05-15-2019, 07:10 AM
Installed the front swaybar last night. FFR instructions state that the sway bar should be horizontal or hang down up to 20deg (See picture). I didn't have a protractor at the time, but estimated ours was approximately 30deg. The car is on the frame dolly and the suspension is not loaded. Won't the sway bar move up towards horizontal when the finished car is on the ground and the suspension is loaded? What is the potential issue if the sway bar hangs more than 20 degrees?
I'd like to avoid trimming the rod ends again.
107239
Jim1855
05-15-2019, 07:38 AM
Brian76,
As you load the suspension (drop it on the ground to ride height) the sway bar will follow the lower control arm. So yes it will become more parallel to ground.
The sway bar should have one end-link attached after ride height is set. The bar shouldn't introduce any tension when the suspension is at it's normal position/height.
Jim
Bob Cowan
05-15-2019, 08:06 PM
The end of the bar moves through an arc, as the tire moves up and down. The end goes down on the inside of the turn, and up on outside of the turn (in relation to the frame). As the end of the bar moves further away from the 90* horizontal mark, it becomes less effective, and imparts less control over movement. If the bar is significantly up or down at rest, then you'll get different effects in a right turn than you would in a left turn. Keeping the end of the bar at 90* will keep the car balanced and predictable through both left and right turns.
Brian76
05-16-2019, 06:46 AM
Thanks Jim & Bob. Looks like the sway bar should be parallel to the frame for optimal performance. Do you recommend I leave the front sway bar as-is and wait until the go cart stage to determine if the rod ends need trimmed more? With the car on the dolly and the front suspension and a-arms hanging down, I'm not sure how parallel the sway bar needs to be to the frame. As you mentioned, it will follow an arc (towards parallel) as the suspension is compressed.
rich grsc
05-16-2019, 08:00 AM
Thanks Jim & Bob. Looks like the sway bar should be parallel to the frame for optimal performance. Do you recommend I leave the front sway bar as-is and wait until the go cart stage to determine if the rod ends need trimmed more? With the car on the dolly and the front suspension and a-arms hanging down, I'm not sure how parallel the sway bar needs to be to the frame. As you mentioned, it will follow an arc (towards parallel) as the suspension is compressed.
Jack up the front suspension till the controller arms are parallel to the ground, then you'll know.
JohnK
05-16-2019, 10:26 AM
Jack up the front suspension till the controller arms are parallel to the ground, then you'll know.
This ^
When I was installing the front and rear sway bars, they looked all wrong to me and I was sure I needed to tweak stuff because something wasn't right. But if you back off the spring seat on the shocks and jack up the suspension until the control arms are parallel you'll have a much better sense for what things will look like when in use and everything makes a lot more sense (at least it did to me).
Brian76
05-16-2019, 11:06 AM
This ^
When I was installing the front and rear sway bars, they looked all wrong to me and I was sure I needed to tweak stuff because something wasn't right. But if you back off the spring seat on the shocks and jack up the suspension until the control arms are parallel you'll have a much better sense for what things will look like when in use and everything makes a lot more sense (at least it did to me).
Thanks!
Bob Cowan
05-16-2019, 01:30 PM
Set the frame at ride height, about 4.5" in the front. Then look at the sway bar ends. The A-arms may not be exactly horizontal at ride height.
Brian76
05-17-2019, 08:51 AM
Set the frame at ride height, about 4.5" in the front. Then look at the sway bar ends. The A-arms may not be exactly horizontal at ride height.
I don't have tires & wheels yet. I suppose I could estimate radius of tire and wheel then jack up the front suspension accordingly.
Bob Cowan
05-17-2019, 09:58 AM
I would wait until you have some wheels and tires mounted. You can get it in the ball park by resting the rotors on some wood blocks. But it won't be quite right, and you'll have to revisit that task again later.
Once you have tires mounted, set them down on a folded plastic trash bag so they will move easily.