Holy hell man, how do you not have more subs??? This is so well put together and high quality, you put in more effort to this than most UA-camrs put into their whole channel.
Thanks for sharing your work. What hardware are you using to log the data and at what frequency? I'm looking to log steering force and maybe a strain gauge on the steering shaft is something I should look at.
I'm using an i100 Instrunet that I've setup specifically for mobile applications. Its a great DAQ platform at a reasonable cost for the quality. I believe I was sampling at 50Hz. I think the steering force idea would work great with a strain gauge applied - I recommend going with a torsion full-bridge setup, it's worked well for me in the past.
Bushing are a great topic to bring up but I've got too much to say to fit in a comment. After I finish setting up the DAQ I've got plans to replace the bushings and I'll be covering their affect in a video then. The short answer version is yes forces from the tire can be picked up. "Impulse" definitely plays a roll, which I'll cover when I dive deeper into bushings, but forces can be captured. Now, if you mean binding in the sense that the suspension isn't traveling up or down like when you over tighten a pivot joint, I'm not capturing that movement here (but soon will be!). Wheel travel would be affected by binding bushings but lateral and longitudinal forces still need to go through the load path from the mass of the vehicle to the tires, even if it means traveling through rigid bushings.
@@DirtyElbowsGarage so I guess I meant like the suspension isn't straight up and down (need compliance in bushings) how do you differentiate a pull/push vs twist/bend. Wouldn't geometry spread the load differently too ie toe in toe out tugging things. Also if you're replacing components wouldn't the metallurgy and thickness change the registered strain to a point the numbers wouldn't be consistent? I'm just an ee and have no idea the mechanical aspect.
@@DirtyElbowsGarage I guess specifically let's say you put the strain gauge on with the car in the air suspension full droop and compliant bushings. As the radius rod travels up it's under compression and is pushing the lca back. If you swapped the lca bushings with solid steel (not heim joints) and set the car down as the radius rod goes through its travel it's seeing more compression from fighting the lca and the lca is seeing bending which depending on which side the strain gauge is on would affect that reading no? So just because there's more force going through the suspension as you drive doesn't mean that force is going through the tires and making you faster right? Let me know if I'm off, I want to learn lol I've got an unfinished caged crx in my garage too
@@supasexystick Ok, I think I'm following what you're saying. If I'm understanding it correctly, yes you're right there are forces that can be built up in the control arms that don't deal with the tires, regardless of compliant or non-compliant bushings. There are a couple ways to work with this. The first is to use the correct strain gauge setups. There are arrangements of gauges specifically meant to distinguish things like bending from tension. It has to do with the type of gauge and placement. The second is to zero the gauge values after these arms are loaded (car on ground). This will negate the inherent loadings, and if the preload is in the opposite direction of what you're measuring, it will be caught after the first few tests with some intuition of how the system should be loaded and then can be corrected out of the data. Third, and I should have said more about this in the video, but more strain gauges are going on the car along with some position sensors( and more). The data collected from the group is going to paint a picture of what forces are doing what, and under what conditions input and outputs are tied together. And lastly, this setup can be used like a traditional dyno - where absolute hp isn't the purpose, its the % improvement that is the purpose. And using it in this way more generated forces would be better when it comes to things like alignment settings, tire pressures, etc.. Now if you significantly change the system, you also need to reset your baseline performance metric as well. What is "significant" actually depends on what you're changing and is a case-by-case scenario. I hope this helps! And get that cage finished up and out on the road!
Holy hell man, how do you not have more subs??? This is so well put together and high quality, you put in more effort to this than most UA-camrs put into their whole channel.
Thanks for sharing your work. What hardware are you using to log the data and at what frequency? I'm looking to log steering force and maybe a strain gauge on the steering shaft is something I should look at.
I'm using an i100 Instrunet that I've setup specifically for mobile applications. Its a great DAQ platform at a reasonable cost for the quality. I believe I was sampling at 50Hz. I think the steering force idea would work great with a strain gauge applied - I recommend going with a torsion full-bridge setup, it's worked well for me in the past.
Would that actually work though? If any bushing is binding wouldn't forces be not actual for the tire etc?
Bushing are a great topic to bring up but I've got too much to say to fit in a comment. After I finish setting up the DAQ I've got plans to replace the bushings and I'll be covering their affect in a video then. The short answer version is yes forces from the tire can be picked up. "Impulse" definitely plays a roll, which I'll cover when I dive deeper into bushings, but forces can be captured. Now, if you mean binding in the sense that the suspension isn't traveling up or down like when you over tighten a pivot joint, I'm not capturing that movement here (but soon will be!). Wheel travel would be affected by binding bushings but lateral and longitudinal forces still need to go through the load path from the mass of the vehicle to the tires, even if it means traveling through rigid bushings.
@@DirtyElbowsGarage so I guess I meant like the suspension isn't straight up and down (need compliance in bushings) how do you differentiate a pull/push vs twist/bend. Wouldn't geometry spread the load differently too ie toe in toe out tugging things. Also if you're replacing components wouldn't the metallurgy and thickness change the registered strain to a point the numbers wouldn't be consistent? I'm just an ee and have no idea the mechanical aspect.
@@DirtyElbowsGarage I guess specifically let's say you put the strain gauge on with the car in the air suspension full droop and compliant bushings. As the radius rod travels up it's under compression and is pushing the lca back.
If you swapped the lca bushings with solid steel (not heim joints) and set the car down as the radius rod goes through its travel it's seeing more compression from fighting the lca and the lca is seeing bending which depending on which side the strain gauge is on would affect that reading no? So just because there's more force going through the suspension as you drive doesn't mean that force is going through the tires and making you faster right? Let me know if I'm off, I want to learn lol I've got an unfinished caged crx in my garage too
@@supasexystick Ok, I think I'm following what you're saying. If I'm understanding it correctly, yes you're right there are forces that can be built up in the control arms that don't deal with the tires, regardless of compliant or non-compliant bushings. There are a couple ways to work with this. The first is to use the correct strain gauge setups. There are arrangements of gauges specifically meant to distinguish things like bending from tension. It has to do with the type of gauge and placement. The second is to zero the gauge values after these arms are loaded (car on ground). This will negate the inherent loadings, and if the preload is in the opposite direction of what you're measuring, it will be caught after the first few tests with some intuition of how the system should be loaded and then can be corrected out of the data. Third, and I should have said more about this in the video, but more strain gauges are going on the car along with some position sensors( and more). The data collected from the group is going to paint a picture of what forces are doing what, and under what conditions input and outputs are tied together. And lastly, this setup can be used like a traditional dyno - where absolute hp isn't the purpose, its the % improvement that is the purpose. And using it in this way more generated forces would be better when it comes to things like alignment settings, tire pressures, etc.. Now if you significantly change the system, you also need to reset your baseline performance metric as well. What is "significant" actually depends on what you're changing and is a case-by-case scenario. I hope this helps! And get that cage finished up and out on the road!