Thought I'd ask in here - delete this post if it's a dumb question.

The obvious answer, I thought, was NO, they do not affect handling, since when the car is on the ground they are just resting against one another.

However, I've been wrong before, so I succumb to the knowledge of the RR/Auto-x forum.

By the way, the dead coils are on Neuspeed sports, and there's about 5 of them. Riding on Bilstein shocks on a 1989 CRX Si.

Alex

 

By "dead coils" do you mean "helper" or "tender" springs? The flat section ones with a really low rate, that just turn into a spacer when the car is sitting on the springs?

Kirk

 

I think that he means the coils on a spring that are already binded before a load is placed on. These act as a spacer, and are sometimes involved to gain a progressive rate on a spring. They will affect the handling only if you have enough travel to coil bind the entire spring. Having dead coils will allow the entire spring to bind sooner.

Short answer: No.

Edit: Many lowering springs have "useless" coils only there to extend the free length of the spring.

 

Okay - well the coils I'm talking about do NOT touch each other when the spring is off the car or the car is off the ground. They are about 1/2 to 3/4" apart either way. Once the car is lowered and set on the ground, these dead coils are directly up against one another.

I can see where the dead coils I'm talking about would actually impede the full travel of the suspension, since they are taking up space that could be used for travel, but I'm pretty sure I'd hit the bumpstops before all the coils were bound against one another. But if that weren't the case, the suspension would go to an infinite spring rate (coils bound against one another) sooner than if there were NO dead coils.

Alex

*EDIT* GSpeedR has the right idea, Kirk. Thanks for the input so far, guys - keep it coming.

 

Ah - gotcha.

The available travel of a coil spring is the difference between its free length and bound-up length. You can estimate it by measuring and summing the spaces between the coils or by the diameter of the wire. You are right on about the rate going to hog-heaven when coil-bind occurs and you need to be sure that the shock isn't bottoming before this happens.

ACTUALLY, you should make sure that your bump rubbers bottom and do their job before either of these things happen - but the fact that you mention them means that you probably get this too.

That extra length might have an influence on the inside wheels, as the suspension goes into droop - relative to static ride height - as the car rolls in a corner but with typical rates and modern antiroll bars, this probably isn't a factor.

I think you have answered your own question.

K

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Knestis &raquo;</TD></TR><TR><TD CLASS="quote">

That extra length might have an influence on the inside wheels, as the suspension goes into droop - relative to static ride height - as the car rolls in a corner but with typical rates and modern antiroll bars, this probably isn't a factor.

I think you have answered your own question.

K</TD></TR></TABLE>

Right - cause the spring, without some of the dead coils, wouldn't be any shorter than say, a 7 or 8" GC race spring...it would most likely still be an inch or two longer. But I do know that the GC and other coilover suspension springs are notorious for popping out of the upper mount.

Anyway, yeah I did answer my own question - the dead coils don't really do a damn thing for the actual physics behind the suspension when the car's on the ground - thanks for the input guys!
Alex