XRAY - Model racing cars

I've been looking for some info on what the difference is in effect of changing shock oil viscosity compared to changing the piston hole size. It seems to me that this is the same thing, but I suspect there is probably a reason to change hole size instead of oil and I would like to understand better, but I can't seem to find any good info about it.

Also, is there some rule of thumb on how much viscosity change equals a holes size change?

Any info would be appreciated.

There isn't a direct ratio to go by. For example, you can't say that 5wt equals .1mm. It changes exponentially, but to what degree I'm not sure. This function also changes with temperature. There are so many variables to think of when you bring droop, the dynamic properties of 30wt silicone oil vs. 45wt silicone oil. How much does the turbulence account for when flowing through a 1.2mm hole vs. a 1.5mm hole, what about 5 holes, or 7-8 holes, etc. etc.

I just go by the rule of thumb the bumpier/bigger the jumps are I go with a smaller hole piston so I can keep thin oil in there to keep the static dampening as light as I can and also get as much pack as possible for landing the jumps and keep the chassis off the ground in bumps.

I've been talking with a local guy, and there are a bunch of things I would like to try with shocks/valving/adjusting the flow, etc but sorry, I'm not really wanting to talk about it, haha!

OK then... The problem I am trying to solve is: I have an indoor track here where I have a very smooth high traction clay surface and the car is handling pretty good for me with the exception of one spot on the track where it is a huge double table top, and the fast line requires that you launch off of the first table top and land flat on the top of the 2nd one. This is where I am having my issues. The buggy tends to land and slap the chassis and then bounce. When it bounces it gets out of shape as I drive off the back side of the 2nd table top. I am trying to figure out how to stop/minimize the bounce but still maintian as much of the other handling characteristics as possible.

So based on what you said, in theory I should try a smaller hole pistion and lighter fluid rather than the larger holes and heavier fluid. Is that right?

One thing to note is I noticed that if I am on the throttle a bit while I am landing the bounce is less, (Im assuming this helps redirect the car more forward right as its hitting the ground and sort of acts like hitting a downside) but the backside of the 2nd tabletop has a tight hairpin right after it so landing on throtle makes it hard to hit that corner without overshooting it.

Any advice?

Looking at in a different way, what tyre inserts do you use . Us uk boys being a bit slow on the insert pick up see the new proline inserts as a big step forward over std. The handling change of the car is large put in a big positive way meaning you can go allot faster in many areas. Areas we thought where shock related actually was tyre & insert.

Bren

The best tires at my indoor track are still the good old panther switch 2.0 in clay compound. Some run the Losi Pink tapers. I made up a new set of tires just last week using the AKA inserts inside the panther tires and they didnt work as well as my old tires with the old fashoned soft foams in them. Just didnt grip as well. I think being harder insert on the hard packed clay surface it reduced the size of the contact patch and therfore reduces the grip. So... unless I learn something different I'm going to stick with the older style inserts for now, the harder new style inserts arent working everywhere else.

I'm going to keep the tire set with the harder foams in the bag though. There are some days when the traction is so high out there the reduced traction of the harder foams will be welcome. But this particular problem I am going to attack with the shock setup. The car is handling good everywhere, I just need to solve the boucing I get in that one spot on the track without killing the rest of the handling.