Fantastic instruction! Only one addition or maybe an addendum would be how the curve changes when towing a gooseneck/5th-wheel trailer, a bumper pull trailer, etc..
The more I view your videos, the greater my understanding of suspensions get. Thank you for lighting some light up on issues that we previously had on our race car.
This helps explain why the rear brakes on my Honda Beat are bigger than the fronts, while the inverse is true for my daily driver. These videos are excellent and make an amazing resource for people like me to learn from!
These videos are great! Thanks for making them. I hope you have lots of success with this channel. Thank you again for sharing your knowledge with us, Hubert!
So, my "short for long" if someone would correct me: We calculate an ideal braking curve based on those values which the weight distribution is the most sensitive (i couldn't get which factor decides the inclination of that line from the ideal 1 grip surface to the crosspoint where the front/rear load meet) Then we size the capabilities of the front and rear calipers according to the ideal line in order to take advantage of what the ideal line shows to be the capabilities of the vehicle (let's say make the actual and the ideal line overlap instead of the actual being linear like those on basic brake pumps are.) Am I on track? I am also wondering how all this connects to tires grip (I suppose it's in the second part I'm gonna watch), and to some adjustable brake bias controls I see people uses. I mean, racecars all uses that and it seems quite sensitive of a parameter to adjust with a scrollwheel while driving... 🤔
The curve is done using different tyre grip, left low grip, right max grip. At max grip you have more weight transfer, so you need to move the balance to the front. Race drivers can change this while driving to find their preferred grade of oversteer.
You could use a simplified 2 d car model. Tyres could be modeled as mu*N, as you increase mu, the moment with respect to baricenter can then be divided by wheelbase to find Nfront and Nrear. This would require some iterations to get the actual normal forces.
Hello, thanks for uploading such great videos. They are truly highly appreciated. However, I still have a doubt, and it is: why isn't the antisquat related to the results of the graphic. Thanks again.
Matthew, the curves I showed were created using a spreadsheet I created myself. The formulas are not very difficult and anyone could easily make a similar spreadsheet. I recommend getting a copy of "Brake Design and Safety" by Rudolf Limpert. I have the third edition and in section 7.3, he talks about creating the ideal, optimum, brake curve.
@@suspensionsexplained Is there a chance you could upload a copy to a public google drive or something? I'd like to illustrate why people are regularly installing dangerous brake systems on aircooled VWs
@@Levibetz this spreadsheet will not work for any arbitrary application. You have to calculate the specific car features. Most importantly, mass and center of gravity height and location between contact patches. Once you know where the mass is steady state, you can see how it transfers under 1g braking. Combining how much weight is transferred to the front tires, compared to the rear tires. In conjunction with their respective widths and pressures (contact patch size). And coefficient of friction... Then You have enough data to determine desired brake bias. Now you have to spec the entire brake system, that is master cylinder to brake caliper piston diameter ratios front and rear to get the proper output. Instead of calculating this. Simply install the brakes you want, along with an adjustable brake proportioner onto the rear brake line. Take the car out and test it in a controlled area. Keep increasing rear brake flow until you can get the rear to skid when braking while cornering.
I am trying to put those diagonal lines representing friction coefficient / deceleration into Excel, but I don't know how to do it without creating a new series for each one. Is there a simple way to do it? This is a fantastic video, by the way!
No I don't. Because brakes are safety critical systems, for liability reasons, I do not share these but the formulas are not difficult to derive or find in text books.
Fantastic instruction! Only one addition or maybe an addendum would be how the curve changes when towing a gooseneck/5th-wheel trailer, a bumper pull trailer, etc..
The more I view your videos, the greater my understanding of suspensions get. Thank you for lighting some light up on issues that we previously had on our race car.
This helps explain why the rear brakes on my Honda Beat are bigger than the fronts, while the inverse is true for my daily driver. These videos are excellent and make an amazing resource for people like me to learn from!
These videos are great! Thanks for making them. I hope you have lots of success with this channel. Thank you again for sharing your knowledge with us, Hubert!
I might be a nerd for liking your channel so much, but I am okay with that.
Thank you! Learned a great deal.
Love your videos, thanks for all your work put into making them! Please continue to educate us :D
Thanks for explanation.. can you provide the equations that helps to generate this curve
thank your video, can you have other video explain more about ECE cure, f line groups and r line groups for design regenerative braking?
Does having staggered wheels like on a Porsche have any influence on the curve?
Thank you sir
how do i create a break curve ??
Use a sledge hammer?
So, my "short for long" if someone would correct me:
We calculate an ideal braking curve based on those values which the weight distribution is the most sensitive (i couldn't get which factor decides the inclination of that line from the ideal 1 grip surface to the crosspoint where the front/rear load meet)
Then we size the capabilities of the front and rear calipers according to the ideal line in order to take advantage of what the ideal line shows to be the capabilities of the vehicle (let's say make the actual and the ideal line overlap instead of the actual being linear like those on basic brake pumps are.)
Am I on track?
I am also wondering how all this connects to tires grip (I suppose it's in the second part I'm gonna watch), and to some adjustable brake bias controls I see people uses. I mean, racecars all uses that and it seems quite sensitive of a parameter to adjust with a scrollwheel while driving... 🤔
The curve is done using different tyre grip, left low grip, right max grip. At max grip you have more weight transfer, so you need to move the balance to the front. Race drivers can change this while driving to find their preferred grade of oversteer.
Thanks
thanks for the video , how to plot this curve ? what is the equation for the curve and the lines?
You could use a simplified 2 d car model. Tyres could be modeled as mu*N, as you increase mu, the moment with respect to baricenter can then be divided by wheelbase to find Nfront and Nrear. This would require some iterations to get the actual normal forces.
Hello, thanks for uploading such great videos. They are truly highly appreciated.
However, I still have a doubt, and it is: why isn't the antisquat related to the results of the graphic.
Thanks again.
Anti-dive and anti-squat geometry doesn't actually reduce weight transfer. They only cancel out the suspension's response to weight transfer.
Where can i generate my own ideal brake curve?
Is that graph something widely available? I'm curious to plug in my vehicle specs to see what the curve looks like (from an academic perspective).
Matthew, the curves I showed were created using a spreadsheet I created myself. The formulas are not very difficult and anyone could easily make a similar spreadsheet. I recommend getting a copy of "Brake Design and Safety" by Rudolf Limpert. I have the third edition and in section 7.3, he talks about creating the ideal, optimum, brake curve.
@@suspensionsexplained Is there a chance you could upload a copy to a public google drive or something? I'd like to illustrate why people are regularly installing dangerous brake systems on aircooled VWs
@@Levibetz this spreadsheet will not work for any arbitrary application.
You have to calculate the specific car features. Most importantly, mass and center of gravity height and location between contact patches.
Once you know where the mass is steady state, you can see how it transfers under 1g braking.
Combining how much weight is transferred to the front tires, compared to the rear tires. In conjunction with their respective widths and pressures (contact patch size). And coefficient of friction... Then You have enough data to determine desired brake bias.
Now you have to spec the entire brake system, that is master cylinder to brake caliper piston diameter ratios front and rear to get the proper output.
Instead of calculating this. Simply install the brakes you want, along with an adjustable brake proportioner onto the rear brake line.
Take the car out and test it in a controlled area. Keep increasing rear brake flow until you can get the rear to skid when braking while cornering.
I am trying to put those diagonal lines representing friction coefficient / deceleration into Excel, but I don't know how to do it without creating a new series for each one. Is there a simple way to do it? This is a fantastic video, by the way!
The only way I've found to do it is to use a new series for each one. You end up with a LOT of series in the graph!
may i ask how you used excel to get the ideal brake curve? I read the text book he recommended but still don't know what formulas to use
How can we make our own ideal brake curve?
Do you share that spread sheet anywhere?
No I don't. Because brakes are safety critical systems, for liability reasons, I do not share these but the formulas are not difficult to derive or find in text books.
Anyone else come here from The Autopian?
Yes but No, I'd never own up to being a member there, a different name to break the association. (-;