Front Suspension Geometry| EP.4 Roll Centre

Episode 4 where we talk all about Roll Centre. There is a way to visualize roll centre which is why we incorporated lines and points to make it easier to follow along. Roll Centre is another big component to your front suspension, but also your rear. We only focus on front suspension but it also applies very similar to the rear. Stayed tuned for Episode 5!!
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Facebook: FDF- Fallaise Design & Fabrication
Website: fdfraceshop.com

[@GarageNation353]

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

[@doriangray2347]

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

[@filsilva7213]

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

[@connorswanson6725]

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

[@joelslifeofcars7221]

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

[@BryanOnofre]

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

[@Indy_Auto_Fab]

Absolutely killer content!! Keep it coming!

[@cookierageracing7052]

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

[@hotrodcasanova3574]

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.

[@Bert1k0]

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!

[@andyslides9598]

Killing it thanks man

[@CotyDemster]

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.

[@FDFraceshop]

The corvette kit has a bracket that the front adjusting arm bolts to. These holes can be used to attach an adjustable linkage to connect to the oem bar or an aftermarket bar. We are currently making a front sway bar for the corvette as we speak so maybe hold out for a bit. Either way, an aftermarket adjustable linkage will be required so that is something that can be purchased ahead of time. The oem bar may interfere with your wheels at full lock.

[@EugenioPicado]

Amazing video and information. Love these episodes

[@off-roadingexplained8417]

Perfect ! This is what I was looking for.

[@robertbenson1966]

Great job on the video, nice rig.

[@blackastraop]

Great explanation, alot more people need to know this 👏

[@jakhy1198]

Great video

[@johniii1220]

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

[@celicasaur]

Very cool

[@waynehowlett9424]

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

[@tougestarsgarage]

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

[@konigvonpreuen8065]

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.

[@jankesbmw]

double wishbone is better in my opinion seems like cars more focused on performance had those fitted as factory, and yes waiting on depth video as well.

[@DrR1pper]

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?

[@Toycoma]

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?

[@richardprice5978]

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

[@TheThiuser]

Props for a good video

[@SidewaysLaz]

🤘🏻🤘🏻🤘🏻

[@tristanbriner7841]

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

[@westingalante]

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.

[@rodrigokrabbenborg5227]

A grip setup i like to see. Front and back

[@JeremyMichaelJordanDIY]

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.

[@jeremyvernon5797]

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?

[@not_virtuality]

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

[@Bigdrift350z]

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 ?

[@FDFraceshop]

They have corrected roll center yes. But every kit should have a sway bar as am option due to the demonstration showing no car being the same. How can a kit work the same when 2 drivers have a ride height difference of 50mm? Which would dramatically change the dynamics of everything, roll center especially so it is important to understand what it is, and then you will know what to change if you don't like how something feels. This is the main goal of these videos

[@MRMAN-wb1tv]

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

[@jankesbmw]

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)

[@FDFraceshop]

Story time, I was in a wreck with another car leading me when he went in to the wall, this damaged my frame rail and pushed my sway bar in to my alternator, so for the next battle I had to remove the bar. With my 8k springs, and dampening not adjusted the car drove very different. I won't say bad because some drivers like transfering the weight alot but the main points to consider are the more power you have and grip you get, the more force is being applied on the center of gravity and this will give you undesirable results as you gain traction. Our car is around 700bhp and uses very grippy tires so the G's we can pull is quite impressive and in my opinion the car would be not as competitive without sway bars. Helps me balance the car and utilize all the potential in the tires before they are gone in 30 seconds 😄

[@jankesbmw]

@@FDFraceshop S chassis had shit design with front arms (aka caster arms) when you are in crash and bend front rails all alignment is fucked, bmw e36/e46 had it better as You would have to damage car beyond repair to get it out of alignement, little wack on s chasiss and you have to check everything. i personally dont like sway bars but still little experience with big bhp cars so maybe loads to learn yet.

[@FDFraceshop]

@@jankesbmw you are not wrong! Watch my pro car breakdown video on how I reinforced the schassis 🤣

[@e30gangsta]

First again let's get it!

[@daviddroescher]

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

[@signal_msw]

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.

[@Deathreaper782]

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