Front Suspension Geometry| EP.4 Roll Centre 

Thank you for the effort put into this video explaining roll center. It helped me understand some of what I was doing wrong modifying my mustang for drifting and maintaining grip up front. Thank you. Keep up the good work.

Killing it thanks man

This is awesome. I always knew such changes would impact my geometry, but could not prove it to people. I would love an explanation of how wider wheels and also tires impacts suspension in terms of vertical forces and the centerline of a wheel. As well as stresses as one moves out from center

🤘🏻🤘🏻🤘🏻

You should really talk about instant centers when talking about roll center. That’s what those two wires are showing, the instant center of one side of the chassis. Some of your drawings are incorrect, because you are not drawing the lines from the instant centers to the opposite side tire contact patch. Overall the basics come across well enough, but your terminology and drawings aren’t quite accurate.

I've watched numerous videos. But this is the first one that lets me understand why my car isn't handling!

So what would you recommend for somebody running your C6 Corvette kit? Is there a sway bar you know of that will work with it? Would love to see some stuff on double wishbone. 👍 Thanks for this whole series. I thought I had a pretty good idea of what was going on but this is way more in-depth than I ever knew.

Fantastic video!! The editing is cool. Very interested in the double wishbone stuff.

This is crazy.... i thought i had a basic understanding of how suspension works until i watched these videos 😳😳. Great info keep it up

Doesn't lowering center of gravity mostly limit body roll? I guess you're just referring to situations where you aren't running a roll-bar? Even if you go beyond the road surface I thought it was common for cars to still perform better for the most part as long as it's not a extremely crazy angle. Only negative tends to be that the car has trouble doing tighter turns because the body rolls gives more grip to the outside tires but when your roll center is so low with anti-roll bars it maintains too much grip on the inside tires and the outside tires lack the necessary additional grip. I feel like just saying 'roll center below ground' being bad isn't really true but I'm not sure who the target audience of this video is as I'm assuming most people don't know enough to actually question what you are saying.

So on a Tacoma from 96 to 04, a common way to lower the front is to do what is called a "ball joint flip" basically you on bolt the lower ball joint and mount it on the top side of the lower control arm. Would this increase or reduce the roll center?

Does increasing the vertical distance of the roll center to center of gravity at the front and reducing it at the rear, cause more lateral weight transfer to occur at on the rear versus at the front?

Is the top wire set where the strut bearing is or is it above it? Try to figure where to take my measurement from.

Can you do an in depth video on MIG welding roll cages?

I was hoping to get some insight on more in-depth stuff like jacking and non-rolling overturning moment. But still a really cool video and great series!

Please do an in depth explanation of front double wishbone geometry. I'm integrating a double wishbone suspension into a macpherson chassis and need to figure out the chassis and subframe mounting points for the control arms.

Awesome video again guys. A video explaining corner weighting would be cool.

Very cool

Can’t wait to see the next one. Keep them coming!

I must have missed it. How do you measure roll center. I know you meantion jacking up and putting wait on the wheels but then what? Is it measured by weight as in I need a weight scale? Or how far the coilover compresses on one side? Maybe I missed it.

ever tried active settings change's aka a computer automatically set's it for best grip or drift on the fly for the front wheels ??? merc ( for the C-class and SLK ) had a special system that did this but im not sure if it got past the 50 or so pilot test cars and into regular hands like you and me

Going back through the FDF Technical videos. Great video, it is sometimes challenging to grasp the technical depth that is going on with the roll center correction and load transfer. I am taking the HP academy suspension programs to knock the rust off of the vehicle dynamics classes I had back around 17 years ago. Here is a decent website for some calculations into roll center vsusp.com/#0.8%26project_name%3Adefault%20values%26trim%7Bbody_roll_angle%3A0%7Cfront.left_bump%3A0%7Crear.left_bump%3A0%7Cfront.right_bump%3A0%7Crear.right_bump%3A0%7D%26front%7Bframe.susp_type%3A0%7Cframe.bottom_y%3A9200%7Cframe.center_to_upper_mount_x%3A28500%7Cframe.bottom_to_upper_mount_y%3A24000%7Cframe.center_to_lower_mount_x%3A17000%7Cframe.bottom_to_lower_mount_y%3A2400%7Ccontrol_arms.upper_length%3A24800%7Ccontrol_arms.lower_length%3A37500%7Cknuckles.hub_to_upper_x%3A15000%7Cknuckles.hub_to_lower_x%3A13000%7Cknuckles.hub_to_lower_y%3A13000%7Cknuckles.hub_to_upper_y%3A13000%7Cknuckles.hub_to_strut_axis%3A14000%7Cknuckles.strut_incl%3A8000%7Csteering.active%3A0%7Csteering.hub_to_outer_tie_rod_x%3A7620%7Csteering.hub_to_outer_tie_rod_y%3A7620%7Cwheels.offset%3A4000%7Cwheels.diameter%3A1500%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A19500%7Ctires.aspect_ratio%3A4500%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7620%7Ctires.compression%3A0%7D%26rear%7Bframe.susp_type%3A0%7Cframe.bottom_y%3A9200%7Cframe.center_to_upper_mount_x%3A28500%7Cframe.bottom_to_upper_mount_y%3A24000%7Cframe.center_to_lower_mount_x%3A17000%7Cframe.bottom_to_lower_mount_y%3A2400%7Ccontrol_arms.upper_length%3A24800%7Ccontrol_arms.lower_length%3A37500%7Cknuckles.hub_to_upper_x%3A15000%7Cknuckles.hub_to_lower_x%3A13000%7Cknuckles.hub_to_lower_y%3A13000%7Cknuckles.hub_to_upper_y%3A13000%7Cknuckles.hub_to_strut_axis%3A14000%7Cknuckles.strut_incl%3A8000%7Csteering.active%3A0%7Csteering.hub_to_outer_tie_rod_x%3A7620%7Csteering.hub_to_outer_tie_rod_y%3A7620%7Cwheels.offset%3A4000%7Cwheels.diameter%3A1500%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A19500%7Ctires.aspect_ratio%3A4500%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7620%7Ctires.compression%3A0%7D%26pref%7Bdiag1.px_per_mm%3A200%7Cdiag1.front_or_rear%3Afront%7Ctab.active%3A1%7Cunits%3A0%7Cshow.f%3A1%7Cshow.ca%3A1%7Cshow.k%3A1%7Cshow.st%3A1%7Cshow.stl%3A1%7Cshow.w%3A1%7Cshow.t%3A1%7Cshow.rc%3A1%7Cshow.rcl%3A1%7Cshow.ic%3A1%7Cshow.icl%3A1%7Cshow.fvsa%3A0%7Cshow.tl%3A0%7Cshow.kpil%3A0%7Credraw_during_drag%3A1%7Cchart.x_axis_center%3A0%7Cchart.x_axis_window%3A10%7Cchart.x_axis_num_steps%3A21%7Cchart.x_axis_field%3Atrim.body_roll_angle%7Cchart.y_axis_fields%3A%5BFR%5D.general.roll_center.y%7D

Absolutely killer content!! Keep it coming!

Great video

I can't really seem to find any videos on actually measuring these things on a car. That is the only thing I am struggling to figure out at the moment

Maybe I missed it in the video but basically you’re saying any roll center height above ground level is good? And after that it just depends on car height, set up, and center of gravity to get that roll center as close to center of gravity as possible?

This view was great 👍. I would like to know about off-road suspension as well. I’m going to look and see if I can find something not on this channel.

I’m late to watching this I’m loving the videos eyes glued and listening in

*So is Thrust Angle, and Steer Ahead in relation to "Roll Center"?*

CG lower than RC would make the car swing like a pendulum instead of roll

Perfect ! This is what I was looking for.

In what order do you consider the most important factors in geometry setup??

Amazing video and information. Love these episodes

Great job on the video, nice rig.

A grip setup i like to see. Front and back

Great explanation, alot more people need to know this 👏

For the angle kits that don’t have the ability to run a sway bar unless you modify it and add a mount point. Are they changing things in the knuckles to change roll center ?

hi, nice video, but i think swaybars important when you do grip driving/racing but drifting car physics are slightly different as car slides instead of cornering , had few cars where i removed sb and had literally no effect on performance - stock sb have so much slack in them so once i fitted coilovers with stiffer springs there was no effect with them or without - that is for low bhp drifting experience (200-300bhp cars)

Props for a good video

First again let's get it!

These videos have helped me confirm the decision on at least 3 setup changes I’d been thinking about doing that I now can’t believe i ever lived with after seeing on paper the differences hahah. I love it man keep em coming