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Shock Pistons

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Old 04-23-2019, 07:18 PM
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Default Shock Pistons

This Goes For Any Car Obviously Other Than The Awesomatix
But Does Any One Run Anything Other Than 4x1.1mm??

I Know In Off Road There Is So Many Different Pistons To Run For Different Tracks/Surfaces
Just Wondering If Anyone Has Tried Anything Else Or Is This Just The Norm We Go By??
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Old 04-24-2019, 07:59 AM
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Tamiya provides several piston hole counts, and I've seen those on various build sheets. Hudy sells at least four different pistons.

I think you're just not seeing it. also.. there's an aversion to really doing shock tuning. I think that may have lead to the current generation of "lets tune flex"... but that's the cranky old engineer in me speaking.
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Old 04-24-2019, 08:14 AM
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You can't compare "off-road" shock tuning to "on-road" shock tuning. For obvious reasons, unless you have jumps, whoops or wall climbs on your "on-road" track...
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Old 04-24-2019, 08:27 AM
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Originally Posted by KE4PJO View Post
You can't compare "off-road" shock tuning to "on-road" shock tuning. For obvious reasons, unless you have jumps, whoops or wall climbs on your "on-road" track...
Yeah, you can. :-) Many of the same factors come into play in both places. Shocks are "a thing" what you do to the shocks is another thing. Packing, frequency damping curves, are all "a thing" you can meausre, and get useful data on. I can't recall the last person I saw talking about suspension frequency, or considered the difference between compression and rebound damping. Changing the speed at which the dampers pack up (affected by size of piston holes and fluid viscosity)

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Old 04-24-2019, 08:48 AM
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Originally Posted by Nerobro View Post
Yeah, you can. :-) Many of the same factors come into play in both places. Shocks are "a thing" what you do to the shocks is another thing. Packing, frequency damping curves, are all "a thing" you can meausre, and get useful data on. I can't recall the last person I saw talking about suspension frequency, or considered the difference between compression and rebound damping. Changing the speed at which the dampers pack up (affected by size of piston holes and fluid viscosity)
OK...
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Old 04-24-2019, 09:15 AM
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Originally Posted by Nerobro View Post
Yeah, you can. :-) Many of the same factors come into play in both places. Shocks are "a thing" what you do to the shocks is another thing. Packing, frequency damping curves, are all "a thing" you can meausre, and get useful data on. I can't recall the last person I saw talking about suspension frequency, or considered the difference between compression and rebound damping. Changing the speed at which the dampers pack up (affected by size of piston holes and fluid viscosity)
Most people get scared by the maths and just copy each other. 4x1.1mm pistons are, however, quite versatile, IF you keep the temperature and suspension frequency in mind. I've got 3x1.1mm with 250w oil in my "wet" car; similar damping ratio with slightly faster pack, but calculated at a lower temperature.
I'm waiting to try a 4x1.1mm on compression/3x1.1mm on rebound 2-way piston, but nobody makes them for TC shocks.
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Old 04-24-2019, 09:26 AM
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Originally Posted by LzREngineering View Post
I'm waiting to try a 4x1.1mm on compression/3x1.1mm on rebound 2-way piston, but nobody makes them for TC shocks.
That's in my queue of things to make.
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Old 04-24-2019, 10:42 AM
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Originally Posted by Nerobro View Post
Tamiya provides several piston hole counts, and I've seen those on various build sheets. Hudy sells at least four different pistons.

I think you're just not seeing it. also.. there's an aversion to really doing shock tuning. I think that may have lead to the current generation of "lets tune flex"... but that's the cranky old engineer in me speaking.

no I know they all have different pistons itís just 99% of the setup sheets everyone runs 4x1.1 and just curious if that just works the best or people are afraid to try stuff...
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Old 04-24-2019, 10:44 AM
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Originally Posted by KE4PJO View Post
You can't compare "off-road" shock tuning to "on-road" shock tuning. For obvious reasons, unless you have jumps, whoops or wall climbs on your "on-road" track...
i know I understand that Iím just saying that people seem to change pistons in off-road far more than Iíve ever seen on onroad just curious why 99% of people run 4x1.1 rather than anything else
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Old 04-24-2019, 10:48 AM
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Originally Posted by LzREngineering View Post
Most people get scared by the maths and just copy each other. 4x1.1mm pistons are, however, quite versatile, IF you keep the temperature and suspension frequency in mind. I've got 3x1.1mm with 250w oil in my "wet" car; similar damping ratio with slightly faster pack, but calculated at a lower temperature.
I'm waiting to try a 4x1.1mm on compression/3x1.1mm on rebound 2-way piston, but nobody makes them for TC shocks.
Ok thatís what I was figuring but wasnít sure if that was the case, cause I would think that there would be different piston setups from carpet or asphalt and to tight tracks to open tracks I just donít get enough track time to really go out and test things like that, and a 2 way piston would be pretty awsome
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Old 04-24-2019, 12:14 PM
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My personal opinion is that TC's typically react to other chassis setup changes more noticeably than shock piston changes so this is usually low on the list. Changing fluid can be useful to suit the conditions and driving style, and effect balance if changing one end of the car. But other setup changes can be more influential and are often easier to make and put back.

A couple years ago I tried a bunch of stuff: Oil weight, progressive pistons, tapered pistons, flapper pistons, number/size of holes, machined pistons. Since trying that I've standardized on 4 x 1.1 pistons and I rarely ever change the oil unless the car needs an overall change in how it reacts. It may just be me but I couldn't feel those changes very well, sometimes the tradeoffs were something I didn't like, and it's more work than I want to put in. I know some guys who can really feel the shock setup changes but I can't and basically stopped playing with the pistons.
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Old 04-24-2019, 06:21 PM
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In my days (mid '80's) our main concern was shock oil viscosity,temp. & foaming. I still don't understand why you would want to change pistons when it's so much easier to change the oil!?
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Old 04-24-2019, 07:36 PM
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Itís funny every used car I buy comes with all those left over pistons lol
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Old 04-24-2019, 08:35 PM
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Originally Posted by 1spunspur View Post
In my days (mid '80's) our main concern was shock oil viscosity,temp. & foaming. I still don't understand why you would want to change pistons when it's so much easier to change the oil!?
That's a good question! So shocks damping is based on velocity. The speed at which the shock "packs up" or it reaches the sharp curve where the shock effectively locks up. That's more affected by orafice diameter. The smaller the hole, the slower the fluid speed where the shock packs up. Even if you change the fluid viscosity.
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Old 04-24-2019, 11:54 PM
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Originally Posted by bLamey470 View Post
no I know they all have different pistons itís just 99% of the setup sheets everyone runs 4x1.1 and just curious if that just works the best or people are afraid to try stuff...
Bunch of stuffs have been tried and 4x1.1 is good for most scenarios. TC shocks only move 2mm, so even less of a factor compared to off-road.
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