Coilover vs. eliminator

[shadowj38]

I’m new to mods. What’s the difference between running a Coilover eliminator and spring behind the LR with a shock in front vs. just running a Coilover shock and spring behind the LR like a dirt late model? Is there a time when one would be better than the other?

[Kromulous]

Indexing of the Cage during travel.

During droop travel (shock in Front) the connection at the Cage moves away from the mount (index) and you will gain shaft speed on the shock (rebound), and then closer under compression, mkaing the shock feel stiffer or more dampening.

In turn, the other way around with a Coilover. Zero Index lessons this effect, but its still there slightly.

The mistake most make is running the same shock on both. Its a completely different set up. Coilover application needs alot more dampening in general. Ive seen some shock graphs with some serious zero point, and compression numbers for a Coil over application.

[shadowj38]

Is there a time when you would want to run one instead of the other or is it more of a driver preference situation?

[Kromulous]

I'll be honest, I would like to know myself, thinking its a Driver pref deal but unsure.

Still trying to get used to the soft spring set ups, and havnt really got into the Coil-over situation but i plan to try.

Maybe someone else can weigh in on it.

[shadowj38]

I’m coming from a late model so that’s all I know is Coilover behind.

[MasterSbilt_Racer]

You are always better off with more travel from your damper. Small adjustments can be much more effective.

[SlicktoSlime]

I really like the coil over. We had a shock built for it and had to mess with getting the transition right on it but there is much less time off the gas with it I feel like.

[shadowj38]

Mastersbilt can you elaborate a little more?

[MasterSbilt_Racer]

Mastersbilt can you elaborate a little more?

A shock only works if there is shaft movement. The faster the shaft moves, the more resistance you get from it, up until a point where someone may valve it to go digressive. The force vs velocity relationship is how it effectively damps out oscillations. The less shaft movement you have for a given wheel movement, the shock has to be stiffer and stiffer. It starts to become more like a hydraulic spring where it's applying a lot of force for almost no movement. It's like spring preload you can't remove.

Most shocks have some hysteresis at direction turnaround, where they do almost nothing. If your shaft travels 1" versus 4", a larger percentage of your travel is "dead".

Your typical lr behind setup is actually a huge magnification of very little shaft movement at full drop and more happens later in the travel. You spend most of your track time near full extension. Therefore your shock has to be really stiff and go digressive to not be too much as the car continues to go lower in height. That transition isn't ideal.