Emulsion Shocks for Cantilever set up

[the Jeffro]

I have been told by someone I really respect in the hobby that emulsion shocks won't perform properly when used laying down in a cantilever system. I have searched and haven't found anything on this. Mine are on the rear of an SCX10. 2 based comp rig for truck bed clearance.

I do understand the difference between the bladder and emulsion shocks but I am unsure if the emulsion's performance would be effected using it like this.

Any experience with this?

[the Jeffro]

I kept searching today and one of the guys in my local group had the right ideal and we talked thru it to come to what we believe is the answer.

With the emulsion shock laying on it's side the air pocket would go from the top of the shock body to the upper side. Considering at least one of the piston holes is most likely in that air pocket it would not dampen as it should. We also think it to be impart because of the location of the air pocket and the piston is not entirely in the shock oil. These two conditions making an emulsion shock ineffective on its side. You can hold and emulsion shock up right and compress it then turn it on its side and notice the difference.

Well gotta buy more RC parts now

[Stollenritter]

Hi Jeffro,
I am running a similar setup on my truggy: horizontal emulsion shocks in a cantilever system to clear the bed

First: emulsion shocks can work in cantilever setups. For example, the Vaterra Twinhammer uses horizontal laying emulsion shocks in its front suspension.
But: As you have experienzed, after sitting for a while the emulsion will split up in oil and air. When the suspension starts moving, the piston will (mostly) travel through air and start mixing oil and air to emulsion. So at start damping is poor, but will get better as air and oil get mixed up. The holes in the piston are designed to work with emulsion to get the desired damping rate. Moving through air, damping is poor - moving through oil, damping is firm.

To get proper damping from start, you just can push the back of your truck a few times by hand to mix up oil and air

[the Jeffro]

I have read that some buggy racers running emulsion shocks will pump or prime them by cycling them several times before a race. I tried this with my powerstrokes on their side and it still does not dampen like it does in the upright position. They could be low on oil because it has been a while since I serviced them. I think for my purposes I am just gonna replace the rear shocks with some bladder style. Thanks for the info @Stollenritter

[Teng]

Originally Posted by Stollenritter

Hi Jeffro,
I am running a similar setup on my truggy: horizontal emulsion shocks in a cantilever system to clear the bed

First: emulsion shocks can work in cantilever setups. For example, the Vaterra Twinhammer uses horizontal laying emulsion shocks in its front suspension.
But: As you have experienzed, after sitting for a while the emulsion will split up in oil and air. When the suspension starts moving, the piston will (mostly) travel through air and start mixing oil and air to emulsion. So at start damping is poor, but will get better as air and oil get mixed up. The holes in the piston are designed to work with emulsion to get the desired damping rate. Moving through air, damping is poor - moving through oil, damping is firm.

To get proper damping from start, you just can push the back of your truck a few times by hand to mix up oil and air

Great to know and learn something new today.

[the Jeffro]

Priming the emulsion shocks does work and would probably work fine on a SCT but for a crawler the movement of the shocks is so few and far between they lose the prime (or mixed oil/air) and are still ineffective. At least on my powerstrokes that is the result I had