Fine tuning shocks

[suchtragedy]

Okay so I've upgraded my stock shocks on a couple vehicles now and have followed recommendations here on these forums for the most part for setup and tuning. But I was just wondering if there's some general rules of thumb that might help me tune my suspension on my own better? Mostly I have trouble telling when something might be too firm. Like how high of a drop test should I be doing before the chassis bottoms out? 2 feet? 3 feet? Rebound rate? Etc.

I know this is probably not a question that can be answered so easily and is probably something you learn more by feel and testing over time rather than general rules, but I assume there are some good base rules people can suggest to make that learning curve less steep.

Thanks in advance!

 

[fpvmiller]

Here's some of my "simple" notes on rc suspensions. Others may have differing views. This is what I referenced when racing.
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Stiffer springs = less grip
Softer springs = more grip

High frequency bumps + stiff springs = bouncy, loss of grip :: softer springs should be used

Smooth tracks + stiff springs = responsive, jump handling

Firm springs + soft damping (damping = piston and shock weight combo) = responsive

High frequency bumps = soft springs, soft damping

Smooth tracks = firm springs, firm damping

Aggressive turn-in, low speed steering = rear upper link at less of an angle (rollcenter) or increase front links angle
** This part is for truggies/buggies or other vehicles that have multiple mounting options **

Bumpy track = high rollcenter, allows softer springs

Smooth tracks = low rollcenter, allows firm springs, jump handling

Shocks with more incline = softer rate
Shocks more vertical = firmer rate
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Hope it helps.

 

[suchtragedy]

Yeah definitely helps my understanding for overall handling.

Right now I am more so general bashing/jumping with the 3-4s plastic chassis trucks and worry about breaking my plastic shock mounts so I have been using stock shock set-up as kind of the baseline. When I built my granite into a diet Pepsi version of the outcast I put 6s outcast fronts (using as rears) and 6s Mojave Fronts (using as fronts) and then changed the springs out because Typhon shocks were too spendy and hard to source.

I could tell the Mojave shocks were way too stiff but felt the Kraton 6s shocks for the rears felt pretty good with zero preload and 50wt oil, but then kept seeing comments that 6s kraton springs were too stiff. So that's where I am at basically, just trying to get a better grasp on what I should be factoring in to determine how to tune better.

 

[Surchaufeur]

My rear shocks are pretty stiff i was running on my backward and it was a bit funny im running 80wt and kraton 4s springs in the rear i think i need to drop the oil weight to 60 or the springs and the front same 80wt with stock springs and i think they are too soft or perfect

 

[fpvmiller]

I still apply some of the notes to bashing because it just helps me know what to expect performance wise.

 

[suchtragedy]

I still apply some of the notes to bashing because it just helps me know what to expect performance wise.

Yeah for sure it definitely helps with overall driveability and handling characteristics. Mostly I am focusing on the balance between being firm enough to soak impact from jumps without breaking shock towers but not too soft and pile driving the chassis into the ground violently and breaking other stuff. Trial and error are teaching me a lot ?

 

[Surchaufeur]

Is going from 80wt to 60wt too much?

 

[fpvmiller]

Is going from 80wt to 60wt too much?

It would depend on your current spring and if you intend to change your spring.

What are you trying to achieve by dropping to 60wt?

 

[Surchaufeur]

It would depend on your current spring and if you intend to change your spring.

What are you trying to achieve by dropping to 60wt?

Its hard to compress than the front
And a lot more time for the shock to rebound the springs are quite soft already

 

[fpvmiller]

Its hard to compress than the front
And a lot more time for the shock to rebound the springs are quite soft already

Yes in that situation dropping the shock weight will help if you plan to keep the same springs. You could also go up in spring rate to match the shock weight. Just depends too on what you have on hand. Do you have 60wt shock oil or do you have the next step up spring rate?

But you are tracking on the right path.

 

[suchtragedy]

Its hard to compress than the front
And a lot more time for the shock to rebound the springs are quite soft already

If dropping oil wt still isn't enough and you don't want to/can't change springs then another option is to drill an additional hole(s) or drill the existing holes larger in the shock piston to allow travel through the oil faster. But be careful this is usually a last option because once you drill it there's no going back and you risk taking out too much resistance and the only way to fix it is to go with thicker oils to slow it back down again.

 

[Surchaufeur]

I had the chance of testing my kraton 4s new suspension set up but it keeps bouncing arround if i don't land right and it tumbles the only thing i broke was a turnbuckle in the rear when i roof landed tried to backflip on a low 3s battery? I had an hpi turnbuckle stole it and threaded the rod ends. The front feels a bit springy but softish the rear is a bit stiff even if i went from 80wt to 50wt planing to go to 40wt next the front is running 80wt with typhon 3s springs and the rear stock kraton 4s springs the kraton 4s springs are a bit softer than typhon front springs.

Yes in that situation dropping the shock weight will help if you plan to keep the same springs. You could also go up in spring rate to match the shock weight. Just depends too on what you have on hand. Do you have 60wt shock oil or do you have the next step up spring rate?

But you are tracking on the right path.

Well i think the front is 80wt typhon front shocks are filled with 80wt right?

 

[fpvmiller]

I think the typhon 3s front shock weight is lower than 80wt. 500cst according to this comparison Kraton4s Vs Typhon3s

 

[Surchaufeur]

I think the typhon 3s front shock weight is lower than 80wt. 500cst according to this comparison Kraton4s Vs Typhon3s

Nono im talking about the typhons 6s shocks not the silly 3s ones XD

 

[fpvmiller]

Nono im talking about the typhons 6s shocks not the silly 3s ones XD

Just checked and the 6s typhon shocks come stock with 550cst. Same stated on the package for my 6s typhon shocks

 

[Surchaufeur]

Just checked and the 6s typhon shocks come stock with 550cst. Same stated on the package for my 6s typhon shocks

:0 okayyy yeah my rear shocks are way too stiff then and what should i do about the fronts? Switch spring for softer of mut heavier oil? 550 cst is like 45ish weight? In the rear shocks i bought them from an outcast 6s fronts. Maybe the pistons are not the same thats why the front shocks are way softer than the rear?

 

[fpvmiller]

Are you using the stock spring rates from the typhon 6s?

 

[Surchaufeur]

Are you using the stock spring rates from the typhon 6s?

Only on the front switched to them becsuse i found the stock kraton 4s front springs to be way too soft maybe it needs thicker oil? The rear i use the kraton 4 shocks springs

 

[fpvmiller]

So the front kraton4s spring is slightly stiffer than the typhon6s front spring. The rear kraton4s stock spring is significantly stiffer than the typhon6s rear spring.

I'm about to crack open my typhon6s shocks soon myself after my run today. I also found it too bouncy. My indications though are that I don't have a heavy enough shock weight as my front nose dives way too easily and then it takes time for the suspension to settle (indicating spring is uncontrolled ie shock oil is too thin/loose for the spring rate).

I'm also going to look at the piston hole size and drill another hole if I have to

I'm currently using 0.72N/mm on the rear and 0.74N/mm on the front for my springs.

 

[Surchaufeur]

The front springs of the kraton 4s is a hair softer than the typhon 6s ones thats what i noticed when i compressed both with my hand