Helper Springs

[Erich Stahler]

So I need to have a helper spring in order to stop the main spring decoupling from the shock absorber top cup on full droop, my question is with an arrangement like in the picture above, when the car is sitting on the ground the top cup edge and the thin edge of the collar that locates the helper spring inside the main spring will be holding the weight of the car, surely that cant be correct?

Second image below hopefully illustrates better what I mean.

[stevieturbo]

Is the helper spring really doing anything ? can you not just get rid of it and screw the adjuster up ?

It's probably not ideal what is happening....not the end of the world either.

Or just get a slightly softer, longer spring ?

[E-bmw]

If that pic it top is the right, surely you have that built up wrong?

See here.

https://www.ap-sportsuspensions.com/product_info/c...

[stevieturbo]

E-bmw said:

If that pic it top is the right, surely you have that built up wrong?

See here.

https://www.ap-sportsuspensions.com/product_info/c...

That shows a setup with much thicker helper springs. Not really the same.

maybe there is a thinner adapter for those helpers that gets around this. Although I'm near sure I used that style of helper on mine at a time, and do not recall any issues like that

That said, if the lower collar was inverted, that might allow the helper to go flat before the alloy parts collided ?

[Erich Stahler]

stevieturbo said:

That shows a setup with much thicker helper springs. Not really the same.

maybe there is a thinner adapter for those helpers that gets around this. Although I'm near sure I used that style of helper on mine at a time, and do not recall any issues like that

That said, if the lower collar was inverted, that might allow the helper to go flat before the alloy parts collided ?

Actually stevieturbo that's not a bad idea, however in the end I have ordered some packers which might be the easiest option, so I can wind the platforms until the spring has a slight preload, taking up the slack with the packers, not as granular as using the platform adjustment but should do the trick.

[GreenV8S]

It looks to me as if the collar that separates the helper spring from the main spring is upside down. Does it have a lip on the other side too? These helper springs are designed to bottom out to carry the load. If the joining collar bottoms out instead I think that won't be located securely and will be vulnerable to damage from impact between the collar and the spring seat.

[E-bmw]

stevieturbo said:

E-bmw said:

If that pic it top is the right, surely you have that built up wrong?

See here.

https://www.ap-sportsuspensions.com/product_info/c...

That shows a setup with much thicker helper springs. Not really the same.

I know that, I was more referring to the fact that I have only ever seen coilovers with the helper at the top, then the collar, main spring & then adjuster at the bottom.

I suppose they could go either way, but that is the only way I have seen them built up.

[stevieturbo]

E-bmw said:

I know that, I was more referring to the fact that I have only ever seen coilovers with the helper at the top, then the collar, main spring & then adjuster at the bottom.

I suppose they could go either way, but that is the only way I have seen them built up.

Doesn't really matter top or bottom. I had mine at the bottom. Although my helpers were something like 450lb, so thicker than the thin ones the OP has.
Although looking at the pic....I inverted mine so I guess it's at the top. So just depends on the actual locating collar.

[GreenV8S]

stevieturbo said:

Although my helpers were something like 450lb, so thicker than the thin ones the OP has.

They sound more like tender springs than helpers. Helpers just stop the main springs rattling loose on droop.

[stevieturbo]

GreenV8S said:

They sound more like tender springs than helpers. Helpers just stop the main springs rattling loose on droop.

Which is exactly what mine are. I just wanted the strongest ones available. With the car on the ground, they were always fully compressed anyway.

Although I disliked that overall setup and now just have a longer single spring

[Krikkit]

stevieturbo said:

Although I disliked that overall setup and now just have a longer single spring

I often wonder why this isn't done more often... Seems like a lot of effort to spec helper/tender springs in.

[LimSlip]

Krikkit said:

stevieturbo said:

Although I disliked that overall setup and now just have a longer single spring

I often wonder why this isn't done more often... Seems like a lot of effort to spec helper/tender springs in.

It's not that simple, you are constrained by the damper length, ride height and the amount of static sag. With higher rate springs you may need to adjust the spring platforms down to achieve the desired ride height and end up with more compression on the damper than there is static sag in the spring. A longer spring (of the same rate) will not fix this, you just end up lowering the spring platform even further.

Shorter dampers, or lower rate springs giving more static sag would fix it, but you may not want the lower spring rate, and shorter dampers may not be off the peg items.

[stevieturbo]

Krikkit said:

I often wonder why this isn't done more often... Seems like a lot of effort to spec helper/tender springs in.

As Lim says, there are always compromises somewhere and it isn't always straightforward either. It's just finding a balance of what fits in the space, and gives you the sort of rates you want over it's range of travel. One spring may not always achieve that. Hence you can get progressive springs, but the shorter the shock and it gets all difficult again.