This might be a dumb question, but does coilover spring length matter? IE 10 or 12 inch on front , 12 or 14 on rear. Or do u just use whatever length u have that is the rate u want?
This might be a dumb question, but does coilover spring length matter? IE 10 or 12 inch on front , 12 or 14 on rear. Or do u just use whatever length u have that is the rate u want?
It only matters if you will coil bind the spring during use . Or get close enough that the rate changes in a way you do not want. Or you cannot set ride height because you cannot get the adjuster nut high or low enough on the body.
That's not what he's saying. He's saying avoid situations where coil bind becomes part of your setup and it won't matter. As long as you aren't in a coil binding situation due to travel, spring length has no effect on performance. A 12 inch spring and a 14 inch spring of the same rate behave the same way until they bind.
I understand what you are saying, however with current set-ups and current front end geometries the difference between a 10" spring and a 12" spring is a very relavent tuning tool.
I understand what you are saying, however with current set-ups and current front end geometries the difference between a 10" spring and a 12" spring is a very relavent tuning tool.
If you do anything more than slightly touch coil bind you will immediately shear the contact patch and push. That even happens with too many shims in your bump stop and coil bind would be much more harsh
Cup Teams do not coilbind the only series that do are Bush, Trucks and K&N because they aren't allowed bumpstops. Cup teams are on 15,000# springs at short tracks and 55,000# at Plate Tracks. They have no Ride Height rule and Aero Is far more important the Mechanical so they only use them for static height and with not having a height rule its raised the rate a lot I have some pictures if your interested. Sounds crazy but its true
Coil binding reacts like a bump stop in a coil loader. The rate increases in the last little bit
Before coil bind then naturally goes to infinity. If your just barely touching coil bind it might not break the contact patch but if it's a big hammer down half mile where you drive the car straight you WILL know when it coil binds just like you will know if you have too many shims in your bump stop. If your running like 1000lb of zero point and you just ride around coil bound it might not take off like that especially if the track is perfectly smooth. I've never tried that though ...
Cup Teams do not coilbind the only series that do are Bush, Trucks and K&N because they aren't allowed bumpstops. Cup teams are on 15,000# springs at short tracks and 55,000# at Plate Tracks. They have no Ride Height rule and Aero Is far more important the Mechanical so they only use them for static height and with not having a height rule its raised the rate a lot I have some pictures if your interested. Sounds crazy but its true
We run bumps on the cup cars and Rentons coil binding in K&N cars. I've never once seen a 55,000lb spring near our shop or any shop I've been in.
Given the ability to run a bump stop or a dual-stage spring setup (both of which are almost infinitely adjustable), why would you ever want to run a coil bound setup which provides no adjustment AND eventually ruins the spring and lord knows what else when you eventually pancake a wall?
Makes no sense to me but a lot things don't...
I have had very good success using Bob Bolles' software. It requires you to measure from the top of the spring to the ground to determine the roll angle. I cant say that I have tested different length springs to determine their effectiveness but I do believe spring length is critical to dlm setups.
its all about dynamic tire load with in the rules giving to you,but its a ton of time and testing, just because it looks good on paper doesn't mean it will work on the track,but spring sizes do not matter to me except to give me the adjustments i may want on the coil overs(room to put rounds in or out)coil bind is something else all together and in the dirt world in my opinion should never be used, there are to many other options for us
I have had very good success using Bob Bolles' software. It requires you to measure from the top of the spring to the ground to determine the roll angle. I cant say that I have tested different length springs to determine their effectiveness but I do believe spring length is critical to dlm setups.
I don't care what the software says, it is completely inaccurate that the sprung mass of a vehicle has any idea where the top of a spring is within a coil-over.
You're either misunderstanding the variable it is asking for or the software is rubbish or some combination of the two.
My guess is that this question is being asked to calculate rear roll center location but the question should be asking where the top of the shock mount (assuming coil-over) is located, not the top of the spring. Load on any coil-over is felt (input) at the ends of the shock, not the ends of the spring. This fundamental fact of physics is why spring length has ZERO effect on vehicle dynamics. That is until coil binding comes into play which no software is going to take into account because it is dependent on way too many variables regarding the spring construction all the way down to how much powder coat they put on it.
If you want proof, go buy or rent yourself a spring smasher and do the homework. Don't trust software written (supposedly) by a guy that has been writing the same 4 tech articles for the last 20 years.
We run bumps on the cup cars and Rentons coil binding in K&N cars. I've never once seen a 55,000lb spring near our shop or any shop I've been in.
From Martinsville, I don't imagine you would see this on a K&N it's totally different. They don't use the springs just for ride height. Like the Cup cars. I guess you haven't been in many shops this year, I don't know what other way to put it but if you're in Charlotte anytime shoot me a PM and you're more then welcome to come by.
Last edited by 7uptruckracer; 12-02-2014 at 08:10 AM.
I don't care what the software says, it is completely inaccurate that the sprung mass of a vehicle has any idea where the top of a spring is within a coil-over.
You're either misunderstanding the variable it is asking for or the software is rubbish or some combination of the two.
My guess is that this question is being asked to calculate rear roll center location but the question should be asking where the top of the shock mount (assuming coil-over) is located, not the top of the spring. Load on any coil-over is felt (input) at the ends of the shock, not the ends of the spring. This fundamental fact of physics is why spring length has ZERO effect on vehicle dynamics. That is until coil binding comes into play which no software is going to take into account because it is dependent on way too many variables regarding the spring construction all the way down to how much powder coat they put on it.
If you want proof, go buy or rent yourself a spring smasher and do the homework. Don't trust software written (supposedly) by a guy that has been writing the same 4 tech articles for the last 20 years.
If you're referring to the original question I asked, you're giving me way too much credit as far as understanding how a dirt late model actually works. The reality is that the little I know about them equates to "I don't know squat". In actuallity , I need to buy some springs and I wondered if there was any particular reason to use one length over another. I really am enjoying reading all the responses from you people who really do understand this stuff. Thanks to all for your responses.
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Spring length
Originally Posted by W2racing
Modern Day Wedge Racing
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