Spring rubber

Just curious to everyone's thoughts on spring rubbers? High, low, middle? Effects of placement and corners to use and not use. Just trying to learn little more. I see guys put in different places and Kenny Wallace YouTube mentioned coil bind better in conventional springs vs coil over got me thinking more. His statement was basically you want coil bind at apex so unloads when getting back in throttle. What's y'all thoughts? How does that interact with a rubber? Is rubber similar to double springs?

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Originally Posted by Jim11h

Just curious to everyone's thoughts on spring rubbers? High, low, middle? Effects of placement and corners to use and not use. Just trying to learn little more. I see guys put in different places and Kenny Wallace YouTube mentioned coil bind better in conventional springs vs coil over got me thinking more. His statement was basically you want coil bind at apex so unloads when getting back in throttle. What's y'all thoughts? How does that interact with a rubber? Is rubber similar to double springs?

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A spring rubber basically makes a spring progressive. It progressively deactivates one coil of the spring so the rate of the spring increases the more that one coil is being inactive by the spring rubber.

Where the rubber is used doesn't really matter, it's still deactivating just one coil for the most part. Now if you put multiple rubbers in, sure you could probably make a difference but just if you didn't butt them together. Like 3 rubbers together (touching each other so 3 revolutions around the spring) but if you installed with a gap (say 1/4 of a coil) then those 3 rubbers would go 3 1/2 revolutions around the spring basically deactivating more coils thus get a stiffer rate. Hope that makes sense.

If all coils on the spirng are spaced evenly, then the placement of the spring rubber has no bearing. If the coils are not equally spaced, then there are a lot of varialbes.

So progressive meaning hits spot making stiffer? Just crutch or another tuning device so don't have to change springs? Appreciate help fellas. Joy of racing is learning. I was never a science student in school but racecars are a different applied science love.

Quote:

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Originally Posted by Jim11h

So progressive meaning hits spot making stiffer? Just crutch or another tuning device so don't have to change springs? Appreciate help fellas. Joy of racing is learning. I was never a science student in school but racecars are a different applied science love.

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Example 300# spring 1" is 300# 2" is 600# and 3" is 900#

could always go to a 325# spring: So 1" is 325# and 2" is 650# and 3" is 975#

Taking liberties here on the rubber and how much it changes rate to make it easier to under stand

So you add 1 rubber to the 300# spring (rubber doesn't fit too tight and rubber isn't super hard so it will compress some.

1" 305# Rubber does little as at 1" each coil barely moves (rate is 305 that inch)
2" 620# Rubber still does little but starting to as the rubber has compresses a little and getting less likely to compress much (rate is 315 for that inch)
3" 975# Rubber is making spring a lot stiffer now (rate is 355 for that inch)

See how they are completely different thru out travel but end up at the same load (975) at 3". If you traveled on to 4" the rubber would end up with more load at 4" then the 325 spring.

Again so much depends on how tight the rubber fits to when the stiffening of the spring happens then how fast it gets stiffer over travel by hardness. Also how many coils the spring has as one rubber in a 14 coil spring will have less effect then one rubber in a spring with only 6 coils.

Sometimes you are using them for a reason, like using a softer spring but making it stiffer to the rate you want at a certain compressed measurement but wanting more preload in the spring when extended. Other times it's just quick and easy to install a rubber over swapping out the spring and resmashing it.

this will take testing, works when it works, it don't when you go the wrong way or too far with it

The spring rubber use in dirt late models has always struck me as funny. The spring rubber was invented as a quick crutch to stiffen a coil when there wasn't another spring available or time to change it. Despite being able to preload, stack, or do anything else you might want to build a load curve, spring rubbers have become like a standard piece of the coilover assembly.

That's why I asked questions about them. It makes more sense now with the coil binding etc that goes on.