Sounds to me like you lowered the spring rate below the point where the shock oil would allow the springs to rebound. You didn't mention retuning the oils to the lighter springs. Anyone else?

Such a formula would not take into account shock positioning, which is different for each model of car, and for each mounting location on the same car. The final spring rate depends on how and where the shock is mounted.

I don't expect that one simple formula would suit all positions or models of car. There would be a bit of measuring individual setups and applying them to the maths.
My buggy has 2 lower positions and 2 upper positions, thats four spring frequencies for each spring. I suspect that the highest spring frequency possible according to it's mounting position, ie correct me if I'm wrong the most vertical, of one spring may have the same or similar spring frequency to that of the next highest spring rate available in the kit mounted in it's most layed over position.
If we had an equation to fill in the different distances of mounting positions and shock angles at different spring rates, corner weight etc. We could come up with a "static" spring frequency for that spring at that position.
Do this for the front and the rear with all possible mounting positions for all spring rates. Then line up the 2 tables you come up with and you will have a list of springs front to rear that are at a balanced frequency !!!!!!!

That is correct, there is not one simple equation to solve for your spring frequency.

Fact is there are a series of equations and lots of variables in solving sprung mass damper system, along with compromises that are made so that the selected setup is suited for what conditions the car experiences the most. Although it should be able to manage worst case weight transfers or jumps, that may only be one very small portion of the track and may be a benefit to tune to what the majority of the track is instead because it will result in faster lap times.

When determining spring rates you need to know the wheel rate as well which is the ratio for a given movement of the wheel and what that is equal to in movement on the shock (This is where the shock angle/ position is taken into account). Once you know this it is just dependent on gross vehicle weight, tire width, power to weight, track (grip) and a few other subjective variables like driver preference and technique.

However, I think the best/ quickest way to go about setup is to just drive and test and try to run the softest rear springs that will keep the car off the track a the ride height you want. Then tune oversteer/ understeer with front springs and comber link locations.

Not to sound rude, I'm sure you are a wealth of knowledge, BUT if you take the time to read this thread !!! The process we are setting out to use, I stress PROCESS, starts with having a range of matched spring frequencies front to rear. This is the first STEP. PLEASE read the thread !!

I'm just seeing if anybody is willing to share their knowledge of such a formula to maybe get a more acurate and maybe time saving way to line up our different spring rates at all their positions from front to rear. Finding our "BALANCED" frequencies.

I think everyone is right, to a certain extent. You could set up equations, but the equation would need to have different constants that would need to be figured for each mounting position (top and bottom) for the shocks, mass on each wheel, ride height (due at least partly to the angle change on the shocks as the suspension compresses), etc. I think Fred's point was to present a simplified process of bench testing to find the balanced springs front to back, which is at least as accurate as trying to come up with the equations, probably even more so because there is a lot more potential for error in determining all of the variables in the equations. In fact, the correct equations for suspension frequencies would take into account the damping rate from the oil, pistons, friction, etc. The equation would get pretty dang hairy at that point. The method Fred has presented simplifies all of this to something we all can do on the bench, and I'm a believer in the method.

I am a fan of simplicity and order. I am also a fan of all things technical. I have no doubt that if someone wanted to take the time to write a program that analyzes every car out there in terms of mounting locations and weight distribution that one could be written to tell you what would balance based on location. I won't say it's impossible because I'm sure it's not. It would be difficult though and I'm not going to try it.

One thing a program like that could never do is tell you how the car actually drives. Nowhere in this process have I ever told you how well your car is going to drive or how to set it up for your track. I can't do that. All I can do is show people a method of balance tuning that allows you to methodically tune different aspects of your cars to address specific handling issues. At the end of the day you will have to spend some time on the bench but also at the track actually driving it trying to figure it out. There are other methods and approaches to tuning and I'm sure some people that would disagree with this method. I'm not here to change anyone's mind but rather to show them an alternative method that adds a sense of order to the standard trial and error or copy someone else methods.

Thanks a lot for your effort on this topic and let us learning something new.

Just if possible, would you mind creating a brief manual for a clear and logical walk-through processes please?

thanks

Please don't get me wrong, although I haven't actually been able to try your meathod yet, I am a strong beleiver that it is by far the best meathod I've ever come across. I was not trying to contradict you on any level. I just felt that it might have been more accurate to calculate the different spring rates in each location to compare the positions compared to the spring rate. And to develop a table of front and rear spring frequencies and be able to line them up to match.

As I've said I haven't been able to test your method yet, But do you think it would be common that 2 different springs would give you the same frequency mounted in opposite mounting positions. ie one upright, one laid over.

Thankyou Fred for taking the time to educate all of us not so educated on suspention geometry. MUCH appreciated !!!!!!!!!!!!!!!!!!!!!!!!

Somebody posted a link to what I think you are looking for back on post# 648 on page 44. It's basically a compilation of Fred's posts on this thread pertaining to the procedure that somebody put together.

I gotta say, though, this thread rocks. Thanks to Fred and everyone who have contributed.

Yes. There is a bit more to things when it comes to how far they are laid over though since the angle that the arm is at in relation to the shock changes constantly with suspension movement but that is getting pretty far along and not something I'm ready to get into right now. I'm not even sure how to start putting all of that into words or that it really even matters all that much for most of us.

I'd love to if I ever find the time. It wouldn't be a very brief manual though. It would probably resemble a long, boring, technical book. It would be easier to make a series of videos going over the basics but again I'd have to find the time.

There are a lot of posts here in the last day or so, I'm responding to this one because IMO it's the best one (outside of Fred's which are always correct).

If that is true, then the antithesis of that must be true, which is:

If you want to know how I really feel, here is is - there is so much bad tech on the last page or so (not from Fred)....

This is correct. And there's absolutely no reason a user couldn't do this, except for....

Let me expand on that a bit, if one were to go to the trouble to calculate wheel rate and wheel frequency, one would proof the data using Fred's method. You would know straight away if your calcs were correct or not.

Those are all independent variables outside of spring frequency that users could isolate for pretty easily (dump the shock oil before you test, make sure the suspension isn't all bound up before you start).

The equations are out there, aren't impossible to use if you can pass high school algebra, and given how easy the internet is to search, the only reason someone hasn't started using them is the same reason nobody has found them so far....

I've been wrong once in my life. It's conceivable that I could at some point be wrong twice. Seriously, I do make my share of mistakes. I just look at them as lessons on how not to do things rather than failures.

This was a bit of irony since you accidentally did today! Unfortunately you only got to watch me (try to) drive a horribly untuned F1 car!