Big Rock Question about tuning some 6s shocks!

[PhoenixFabworx]

I put typhon 6s shocks on both my brcc and my wifes granite and Im thinking i need to run a little thicker shock oil. The problem im having is a pretty severe bounce when landing... We are airing these things out so the landings are pretty violent at times! Im familar on how everything works but I recently got back into rc so my knowledge is limited.

What oil weight are you guys running in the 6s shocks for heavy bashing?

Also one more question..
How much preload are you guys running on the your rigs? Im pretty sure my adjusters are around 3/4 of the way down the shock shaft..

I apprecate any info you guys have to offer!

 

[Primarrma]

The bounce is most likely from the springs, did you change the oil in the shocks before you installed them or did you keep the stock oil? I found them to be to heavily dampened from the factory, but there is no real bounce. I have my set preload as loose as possible, the springs are only just compressed on the collars.

I am running a 6s blx system and sometimes 4s I have the m2c motor mount installed also, so my car is pretty heavy.

Front and rear will be different, due to the spring length. The front springs are a little short in my opinion.

 

[GRC]

Stiffer shock springs reduce bounce when landing. I use
front Kraton springs for the REAR https://www.arrma-rc.com/part/AR330507
front Mojave springs for the front https://www.arrma-rc.com/part/ARA330644

 

[Primarrma]

Stiffer shock springs reduce bounce when landing. I use
front Kraton springs for the REAR https://www.arrma-rc.com/part/AR330507
front Mojave springs for the front https://www.arrma-rc.com/part/ARA330644

Maybe what I think is as bounce is not? If you have heavy springs and thick oil or less/smaller holes in the pistons, then I would think that the truck would be less bouncy, but with heavy springs and light oil or more/bigger holes in the pistons then I would expect it to be bouncy. When jumping there are a few things going on, if you have a lot of dampening, so slow response and a lot of resistance in the shock, you will have all the energy of the landing being taken up by the shocks, if there is less resistance then it will be taken up by the shocks and the chassis. What can be happening is that the bounce is created by the chassis hitting and rebounding off the ground. This is not a bad thing if it's controlled, it is a bad thing if it is the springs doing this with little restriction from the oil.

If you increase your spring strength you will need to increase your oil weight. To me the ideal is to have a reasonable response for driving over uneven ground. If it's over sprung and over dampened your truck will just be getting thrown all over the place when it hits bumps and it will be harder to turn into corners. Think of it like a road car really stiff and designed to corner on hard surfaces.

A nice plush setup will allow the individual arms to follow the terrain and then recover quickly enough to be ready for the next bump, if it is not sprung enough it will bottom out all the time and if the oil is too light it will not absorb the bumps and will just bobble about and lean to far in the corners, but it is a fine line.

A 3s BRCC weights a fair bit less than a 6s Typhon, so the springs and oil are too heavy from factory in my opinion.

If you drop your car from about waste height what is the reaction, does the car bottom out? Does the car bounce back up or does it stop dead when it hits down, and does the front or rear react differently?

 

[GRC]

As you noted, bounce back from jumping is from the chassis hitting the ground. I understand why you think stiffer springs will make it bounce back even higher. But bounce back from jumping is mainly the chassis bouncing. Stiffer springs reduce the chassis impact and thus the bounce back. I'm a jumper and tried thicker oil. It didn't make much difference. Stiffer springs made all the difference.

In other situations like rough terrain, stiffer springs will certainly make an RC bounce more. But this has nothing to do with chassis impact. Which is why if you get stiffer springs, you'll want heavier oil to dampen the action of the springs.

I've discussed this in a few threads recently. Shock setups for landing jumps versus running on rough terrain are completely different. You have to choose which is your priority and find an appropriate balance.

My car will touch bottom over 2 feet, no bounce back. By design, both front and rear react equally. I checked this by videotaping jumps and adjusting accordingly. If the rear was bouncing more I stiffened it. In the next session, it bounced less. On the ground, the car definitely handles better with looser shocks, but my priority is landing jumps.

 

[Primarrma]

As you noted, bounce back from jumping is from the chassis hitting the ground. I understand why you think stiffer springs will make it bounce back even higher. But bounce back from jumping is mainly the chassis bouncing. Stiffer springs reduce the chassis impact and thus the bounce back. I'm a jumper and tried thicker oil. It didn't make much difference. Stiffer springs made all the difference.

In other situations like rough terrain, stiffer springs will certainly make an RC bounce more. But this has nothing to do with chassis impact. Which is why if you get stiffer springs, you'll want heavier oil to dampen the action of the springs.

I've discussed this in a few threads recently. Shock setups for landing jumps versus running on rough terrain are completely different. You have to choose which is your priority and find an appropriate balance.

My car will touch bottom over 2 feet, no bounce back. By design, both front and rear react equally. I checked this by videotaping jumps and adjusting accordingly. If the rear was bouncing more I stiffened it. In the next session, it bounced less. On the ground, the car definitely handles better with looser shocks, but my priority is landing jumps.

I have a bunch of race kit cars and arrma cars built to run on track, all of them run light oil and light springs, I have no issues with bouncing, I have a heavily sprung Kraton and it nearly flips over when it lands. I guess it all depends on your perspective and the results that you personally achieve.

 

[GRC]

When you land on all 4 tires, does the Kraton flip forward or backward? If if flips forward, the back is too loose relative to the front and is bouncing the Kraton forward. You need to stiffen the back springs, or loosen the front springs, or a little of both. If the front in bouncing up more than the back, do the opposite. If both the front and back bounce too much that means you have to stiffen both front and back, etc. Videotaping exactly what happens on impact really does help.

 

[Primarrma]

When you land on all 4 tires, does the Kraton flip forward or backward? If if flips forward, the back is too loose relative to the front and is bouncing the Kraton forward. You need to stiffen the back springs, or loosen the front springs, or a little of both. If the front in bouncing up more than the back, do the opposite. If both the front and back bounce too much that means you have to stiffen both front and back, etc. Videotaping exactly what happens on impact really does help.

I don't know if I can get much stiffer springs than the Nero springs I'm running?

 

[GRC]

Well you can adjust them. I still get bounce on bigger jumps, but it's a balanced bounce, so it doesn't flip me over when I land right. (If you don't land right, of course you can flip over.) It's not just about stiffer, it's how stiff the front and back are compared to each other that will make the car flip forward or back after landing. Also, with Nero springs, you may need very heavy oil, those are crazy stiff. East Tactics has a video suggesting using 5k diff oil with Nero springs on a Kraton (titled "3 months later")

Example: Both videos have the same shocks and springs (the pistons are different). In the first video, the back spring is looser, You'll notice the back end tends to kick up even when landing all four tires at the same time.

Next video. Tightened the back spring just one turn. No more back end kick up when I land on all four tires. Both videos are after alot of trial and error and adjustments.

 

[parcou]

Well you can adjust them. I still get bounce on bigger jumps, but it's a balanced bounce, so it doesn't flip me over when I land right. (If you don't land right, of course you can flip over.) It's not just about stiffer, it's how stiff the front and back are compared to each other that will make the car flip forward or back after landing. Also, with Nero springs, you may need very heavy oil, those are crazy stiff. East Tactics has a video suggesting using 5k diff oil with Nero springs on a Kraton (titled "3 months later")

Example: Both videos have the same shocks and springs (the pistons are different). In the first video, the back spring is looser, You'll notice the back end tends to kick up even when landing all four tires at the same time.

Next video. Tightened the back spring just one turn. No more back end kick up when I land on all four tires. Both videos are after alot of trial and error and adjustments.

Good vid...thx

In both those videos are you weighted on the same shock oil in f/r or did you vary your shock oil for the f/r?

Thx

 

[GRC]

Good vid...thx

In both those videos are you weighted on the same shock oil in f/r or did you vary your shock oil for the f/r?

Thx

Same oil in front and rear. Many use heavier oil in front since the springs are stronger. I'm still adjusting and experimenting, so for now using the same weight is easier, more economical. (80wt looks like it's too stiff, I broke my Tekno shocks that withstood everything before )