Sand rail project tuning

[Brady Matthews]

I am building a sand rail out of a 2wd slash. I am wonder what the best base tune for the sand dunes. I am currently running 30w shock oil and no diff oil. Is there anything I should change about the chassis? It is an older slash. Anything helps.

 

[CertifiedMike]

Hey Brady.
I don't own a Slash so I can't help you with the numbers but you're prob going to want to run some oil in that diff.
An open diff on the sand will likely just allow the unloaded wheel to spin and dig a hole, burying the car.
Paddle wheels in the back an wide, floaty ribbed tired in front for good turning bite without sinking into the sand.
I would be looking for soft springs and lower weight oils to help absorb the uneven dunes and keep the tires on the sand as best as possible.

 

[Brady Matthews]

Hey Brady.
I don't own a Slash so I can't help you with the numbers but you're prob going to want to run some oil in that diff.
An open diff on the sand will likely just allow the unloaded wheel to spin and dig a hole, burying the car.
Paddle wheels in the back an wide, floaty ribbed tired in front for good turning bite without sinking into the sand.
I would be looking for soft springs and lower weight oils to help absorb the uneven dunes and keep the tires on the sand as best as possible.

Thank you for this information. It really did help alot.

 

[TeknoJ]

You always need fluid in the diffs, always.
Try a 10k or even go up to 12k or 15k diff fluid. Those should be plenty thick but not too thick. Most kits suggest around 7-10k diff oil in the rear anyway as a baseline (for track purposes).
Just set the suspension up real soft and it should be good. 30wt in the shocks or just slightly lighter than that should be a good starting point. I hope this helps.

 

[Brady Matthews]

You always need fluid in the diffs, always.
Try a 10k or even go up to 12k or 15k diff fluid. Those should be plenty thick but not too thick. Most kits suggest around 7-10k diff oil in the rear anyway as a baseline (for track purposes).
Just set the suspension up real soft and it should be good. 30wt in the shocks or just slightly lighter than that should be a good starting point. I hope this helps.

This really helps, thank you. I have been using Grease in my diffs, is this bad?

 

[Lukedavis]

This really helps, thank you. I have been using Grease in my diffs, is this bad?

Is it the stock diff that comes in the slash?

 

[Brady Matthews]

Is it the stock diff that comes in the slash?

Yes

 

[TeknoJ]

Yes

I’ll be honest I don’t have a slash but if you emptied the diff and it had silicone fluid, I would use fluid and not grease. Grease doesn’t provide the tune-ability like silicone oil does. Grease is just that…. Grease. It won’t kill your diff but I think you are missing out on some subtle changes to the way the car will feel or drive. You can tune or hone in on the perfect set up for sand with silicone oil in the diffs.
I wish I could give you a magic number on what to start with but I can’t, I don’t run my stuff in the sand because it’s just not the terrain I have available. Start with stock recommendations and what I recommended earlier and go from there. Pretty soon someone will ask this same question and YOU will be the one telling THEM how they should set up the truck, it’s all part of this hobby. LEARNING!

Thicker oil is more locked, thinner is more open.
Tekno has a good guide on this and @bill_delong has posted this info many, many times. Do a search for some set up guides and most of all good luck! Tell us how this goes.

 

[Brady Matthews]

I’ll be honest I don’t have a slash but if you emptied the diff and it had silicone fluid, I would use fluid and not grease. Grease doesn’t provide the tune-ability like silicone oil does. Grease is just that…. Grease. It won’t kill your diff but I think you are missing out on some subtle changes to the way the car will feel or drive. You can tune or hone in on the perfect set up for sand with silicone oil in the diffs.
I wish I could give you a magic number on what to start with but I can’t, I don’t run my stuff in the sand because it’s just not the terrain I have available. Start with stock recommendations and what I recommended earlier and go from there. Pretty soon someone will ask this same question and YOU will be the one telling THEM how they should set up the truck, it’s all part of this hobby. LEARNING!

Thicker oil is more locked, thinner is more open.
Tekno has a good guide on this and @bill_delong has posted this info many, many times. Do a search for some set up guides and most of all good luck! Tell us how this goes.

Thank you, will do

 

[Lostinthewoods86]

The stock diff isn’t sealed though.

 

[CertifiedMike]

I was just about to mention, grease is used in unsealed diffs where oil must be sealed.
I hadn't thought of it. I don't know the Slash well.
Be sure to use a silicone based grease.
There have been lots of threads about this. Botton line is that if the product contains petroleum, it can damage plastic and rubber. Play it safe imo.
Try to find a lightweight grease for now if possible. If you are unhappy with the way it handles, maybe you could find a sealed upgrade?
You can always try changing grease but thsts a pain to do. Cleaning grease is more difficult than oil too.
I would think theres a sealed upgrade you can buy.

 

[TeknoJ]

Oh I didn’t know it wasn’t sealed…. I wouldn’t have known because I dont have a slash!

 

[Lostinthewoods86]

Oh I didn’t know it wasn’t sealed…. I wouldn’t have know because I dont have a slash!