Anecdotally, in my experience making digital cars for computer simulation, key point 2 is important. Due to how all the suspension factors combine (castor/camber/SAI/bushes) under a driving load, the static alignment *will* be different to the alignment when driving at a steady state on a smooth flat road. Start adding potholes and corners into the mix and the numbers change drastically. Bonus note, changing any of those single above factors does not result in easily isolated changes. Change one, and all the other values will also change, sometimes by a considerable amount when the car is in motion!
Bonus bonus note. Suspension can be very difficult to test. In a simulation I can easily A-B test changes within a few seconds on the exact same section of road. So you would think it would be easy to test. Yet I still find myself falling into the trap of thinking I have felt a difference when in practice I realise a few seconds later I actually pressed the wrong button and the car setup hadn't changed at all. Driving style has such a big impact and its difficult to control for between tests, equally changes can make the car feel faster, but then when timed are actually slower. So my (potentially ill advised due to lack of real world experience) advice would be to try and get data if possible if you are making lots of changes, if using a track, time yourself; use dash-camera footage and compare to see if there is a visual difference on the same corner, perhaps even a camera on your inputs so you can see if you are being more or less aggressive run to run. The rabbit hole is very deep and the butt dyno is not very accurate.
Hi Julian, My copy is being delivered tomorrow (UK), and I look forward to learning a lot more about this topic, as I did with your other books on aerodynamics.
If you enjoy it, don't forget to leave a detailed review on Amazon. (It's one of the few ways that self-published authors can promote their books.) And if you didn't enjoy it, tell me why!
I come from the motorcycle world, but I would like to get more into cars. So I ordered the book two days ago, and it just came in It’s pretty big/ comprehensive, I look forward to going through it 👍
If you enjoy it, don't forget to leave a detailed review. (It's one of the few ways that self-published authors can promote their books.) And if you don't like it, tell me why!
Hi Julian, I saw all your books listed on Amazon, but some seems to have overlapping topics, so could you please separate the must have from the nice to have in order to know which we should prioritize. Thanks.
Vehicle Aerodynamics - Testing, Modification & Development: For road, racing and alternative transport Vehicle Ride and Handling - Testing, Modification & Development Car Electrical & Electronic Systems Optimising Car Performance Modifications: Simple methods for measuring engine, suspension, brakes and aerodynamic performance gains Car Suspension: - over 120 years of ride and handling A Century of Car Aerodynamics: - the science and art of cars and airflow
I just ordered your book (to be delivered tomorrow). But for my curiosity (and the interest of other viewers), when you state factors affecting handling, like the ratio of front and rear roll stiffness, does the book provide some formulas to calculate this? I mean, it’s great to understand these factors that affect handling, but if the reader has no clue how to calculate the current ratio, what is the desired ratio, and what changes to spring rates and/or swaybars are needed to make the ratio change, then how will users benefit? I think that many people who add suspension mods to their vehicles just look at what aftermarket parts are available, and then read some blogs to see what people promote, and then just follow the crowd. There is no guarantee that the manufacturer of those aftermarket swaybars, or that coilover setup, did the research before creating their products, and they never provide information about the calculated or measured changes in roll stiffness, front/rear roll stiffness ratios, etc. And if you combine Vendor A swaybars with Vendor B coilovers, you have changed the overall result of adding either one, and how do you calculate what changes have actually been made?
I do not show calculations such as you describe. Basically that's because (1) it is overly complex and (2) you need data that you are very unlikely to have for your car. However, I do show how to calculate different spring and sway bar stiffnesses. All suspension development, even by manufacturers, is a test and develop process. So for example, if the car understeers a bit, you might increase rear roll stiffness by - say - 50 per cent and then assess the results. If it understeers a lot, you might double rear roll stiffness. If the car is overly soft in damping, you might go to aftermarket dampers, and so on. Remember that ride and handling are highly subjective: what you like, I may not, and vice versa. They key point of the book is that you should make specific changes aiming at improving identified deficiencies.
The quote "People confusing themselves and others with misunderstood complexities" is the perfect explanation of human condition in general.
No joke!
Anecdotally, in my experience making digital cars for computer simulation, key point 2 is important. Due to how all the suspension factors combine (castor/camber/SAI/bushes) under a driving load, the static alignment *will* be different to the alignment when driving at a steady state on a smooth flat road. Start adding potholes and corners into the mix and the numbers change drastically.
Bonus note, changing any of those single above factors does not result in easily isolated changes. Change one, and all the other values will also change, sometimes by a considerable amount when the car is in motion!
Bonus bonus note. Suspension can be very difficult to test. In a simulation I can easily A-B test changes within a few seconds on the exact same section of road. So you would think it would be easy to test. Yet I still find myself falling into the trap of thinking I have felt a difference when in practice I realise a few seconds later I actually pressed the wrong button and the car setup hadn't changed at all. Driving style has such a big impact and its difficult to control for between tests, equally changes can make the car feel faster, but then when timed are actually slower.
So my (potentially ill advised due to lack of real world experience) advice would be to try and get data if possible if you are making lots of changes, if using a track, time yourself; use dash-camera footage and compare to see if there is a visual difference on the same corner, perhaps even a camera on your inputs so you can see if you are being more or less aggressive run to run. The rabbit hole is very deep and the butt dyno is not very accurate.
Hi Julian, My copy is being delivered tomorrow (UK), and I look forward to learning a lot more about this topic, as I did with your other books on aerodynamics.
If you enjoy it, don't forget to leave a detailed review on Amazon. (It's one of the few ways that self-published authors can promote their books.) And if you didn't enjoy it, tell me why!
Dang it! These videos are going to convince me to buy this book...
I come from the motorcycle world, but I would like to get more into cars. So I ordered the book two days ago, and it just came in
It’s pretty big/ comprehensive, I look forward to going through it 👍
If you enjoy it, don't forget to leave a detailed review. (It's one of the few ways that self-published authors can promote their books.) And if you don't like it, tell me why!
How the hell are people getting the book in such a short term, I’m waiting for mine for almost two weeks
If I ever get to the point of tuning my old MR2 Spyder, I´ll surely buy all those books and do it professionally.
Hi Julian, I saw all your books listed on Amazon, but some seems to have overlapping topics, so could you please separate the must have from the nice to have in order to know which we should prioritize. Thanks.
What topics are you interested in?
ha I was just about to ask the same thing. I vaguely remember Mr Edgar in a past video, talking about this exact issue.
Again, you need to nominate what you're interested in.
@@JulianEdgar just cars :) I love cars and love to understand everything about it.
Vehicle Aerodynamics - Testing, Modification & Development: For road, racing and alternative transport
Vehicle Ride and Handling - Testing, Modification & Development
Car Electrical & Electronic Systems
Optimising Car Performance Modifications: Simple methods for measuring engine, suspension, brakes and aerodynamic performance gains
Car Suspension: - over 120 years of ride and handling
A Century of Car Aerodynamics: - the science and art of cars and airflow
I just ordered your book (to be delivered tomorrow). But for my curiosity (and the interest of other viewers), when you state factors affecting handling, like the ratio of front and rear roll stiffness, does the book provide some formulas to calculate this? I mean, it’s great to understand these factors that affect handling, but if the reader has no clue how to calculate the current ratio, what is the desired ratio, and what changes to spring rates and/or swaybars are needed to make the ratio change, then how will users benefit?
I think that many people who add suspension mods to their vehicles just look at what aftermarket parts are available, and then read some blogs to see what people promote, and then just follow the crowd. There is no guarantee that the manufacturer of those aftermarket swaybars, or that coilover setup, did the research before creating their products, and they never provide information about the calculated or measured changes in roll stiffness, front/rear roll stiffness ratios, etc. And if you combine Vendor A swaybars with Vendor B coilovers, you have changed the overall result of adding either one, and how do you calculate what changes have actually been made?
I do not show calculations such as you describe. Basically that's because (1) it is overly complex and (2) you need data that you are very unlikely to have for your car. However, I do show how to calculate different spring and sway bar stiffnesses. All suspension development, even by manufacturers, is a test and develop process. So for example, if the car understeers a bit, you might increase rear roll stiffness by - say - 50 per cent and then assess the results. If it understeers a lot, you might double rear roll stiffness. If the car is overly soft in damping, you might go to aftermarket dampers, and so on. Remember that ride and handling are highly subjective: what you like, I may not, and vice versa. They key point of the book is that you should make specific changes aiming at improving identified deficiencies.
Will we ever get a digital version available for purchase?
No.
I'd argue the book is cheap. Considering the quality of information it contains, it's a real bargain.
Remember folks, "poor man buys twice"