Wraith 1.9.2

[Topher Builds]

Looking really good. Will you end up selling those links as a set?

[B-MOW71]

Originally Posted by Duuuuuuuude

Do you see it?

I SEE how good it looks! Great looking rig!

[Duuuuuuuude]

Originally Posted by Pant Danza

Looking really good. Will you end up selling those links as a set?

I have zero interest in producing links. I barely like making them for myself. They shouldn't be too hard to source though.

[Duuuuuuuude]

So....spring and shock tuning. Suspension tech can be hard stuff to grasp. It took me a long time to wrap my head around and make sense of it all, especially since I was trying to absorb massive amounts of it at one time. Eventually most of it clicked into place, and since I'm all about sharing, I'm going to show you guys the technique I use when I start tuning. This will be spread out across several posts as I progress, so stay tuned if you are interested.

If you're interested in this kind of stuff, you can also check out my 4 Link thread here: Another 4 Link Thread

Years ago when I was racing short course trucks and struggling with my setup, I stumbled upon a thread over on rctech.net that literally changed my racing life. "Tuning with Camber Links" was the title, but it quickly moved away from that subject and jumped feet first into general suspension tech, starting with springs and dampening. The method that was described by user Fred Swain is super simple but yields amazing results. The whole point was to start with a balanced setup as a foundation, then tune everything else from there. I've done it to every rig I've owned. The process is as follows:

1. Remove the shocks, drain all of the oil, then reinstall in their most vertical position. Put as much preload into the springs as possible, but keep the rig sitting at the same attitude as it normally would.
2. Set up some sort of device to capture video.
3. Figure out how high you can drop the rig without it bottoming out.
4. Hit record, drop the rig from the predetermined height and capture it falling and rebounding.
5. Stop recording, and play it back at a slow speed if available. If it's not available on your device, upload it to youtube and play it back as slow as you like.

What you want to see is how quickly each end of the rig rebounds from the drop. Ideally you want them to fall and rise together. If it doesn't, you've got a pair of springs that are either too stiff or too soft. Remember that preload doesn't change spring rate, it only sets ride height.

Here's the test with my rig. It's important to do this with everything on board that you would normally have. Batteries, scale items, etc. Youtube will let you slow things down to about 25%, which is good, because the bounce happens fast.

[Duuuuuuuude]

It actually did really good. The front was a tad bit slow compared to the rear, but still really close. I've had rigs that were ridiculously unbalanced.

Lets say that this was one of those horribly unbalanced rigs and the nose slammed down hard and bounced back much slower than the rear. Clearly the front will need more spring, or the rear would need less. You can tune in either direction, it all depends on what you'll be doing with the rig and the parts you have on hand. Either way, you want a spring that will let the suspension work in the environment you put it in. Not overly soft, not overly stiff. A U4 rig will want stiffer springs because of jumps, bumps, speed, etc, where a trail rig can easily get away with something softer. Soft springs are not necessarily a bad thing, and don't let anyone tell you different.

If I didn't have springs I could simply lean the rear shocks over a bit. Leaning a shock away from vertical changes it's effective rate, and makes it progressively soft.

Crawlers typically don't have a ton of adjustment here, so we'll just do the best we can. Since it's really close and I'm relatively sure that I don't have any springs in that diameter, I'm going to lean the rear shocks over one hole and call it good.

It's important to remember that every rig is going to be different. Just because I do a thing to mine doesn't mean that it'll have the same effect on yours. It's also important to remember that as I start adding weight in different places I will have to do this test again at some point and correct the spring rate to make sure that it's not getting too out of whack. The goal here is balance. Anything that throws it off is going to have to be accounted for. Even if you can't get it perfect, getting it as close as you can is going to be better than nothing.

[Duuuuuuuude]

Time for shocks. As with all aspects of tuning, you set them up for the conditions they will be operating in.

If we want to get all super-technical about it, the springs are the things that actually absorb shock, and the shocks are the things that dampen the springs reaction to that shock. Thin oil lets the spring react quickly, thick oil makes it react slowly.

The manual didn't specify, but I'd guess the stock oil to be 20-30ish weight. Either way it seemed kinda thin and attributed to the rigs flippy floppy nature. I decided to take the biggest swing I could and refilled them with the heaviest oil I had on hand, which was 50wt.

The rig was immediately stiffer and had lost almost all of it's bounce. Breaking out the incline board, torque twist was about half of what it was before, and I gained another degree of angle. It'll now do 56.5* and the tires have reached their limit. A little momentum will get it a few inches up, then it just sits and spins.

So that's good right? Kinda, but not really. Tuning is give and take. The stiffer suspension and increased climbing ability made for a very unstable ride on my little rock pile. It spent a lot of time teetering back and forth or 2 or 3 wheels instead of following the terrain. What I'll need to do now is dump the oil and refill with something lighter, retest, and repeat until I'm happy. It's pretty obvious that I'll lose a bit on the vertical, reclaim some torque twist, but gain back some real world drivability. And that's all ok. I really don't care about vertical ability and torque twist right now. Spending the time to get the springs and shocks right at the start will make everything else easier.

I'd also add that if you are new to suspension tuning, it's perfectly fine to make wild swings in adjustments, as long as you remember to only do one at a time. Learning the effects of those adjustments is far more important than slowly creeping up on what you think will be the perfect setup and being unsure of what you've actually done.

[Topher Builds]

Enjoying following along here, a lot of good information to noodle on.

This is great. Are you sticking with stock shocks?

[Duuuuuuuude]

Originally Posted by Pant Danza

This is great. Are you sticking with stock shocks?

For now. They aren't leaking so I'm not in a hurry to replace them.

[twisted]

i went with dravtech shocks on mine.

[MaX-D]

Originally Posted by Duuuuuuuude

Do you see it?

I dig these wheels. What are they? And where can I get some? Do they make them in 2.2?

Sent from my LM-G710VM using Tapatalk

[HumboldtEF]

Thanks for sharing the suspension tuning run down. Thats not something I ever really test in depth.

[Duuuuuuuude]

Originally Posted by MaX-D

I dig these wheels.

Thanks.

Originally Posted by MaX-D

What are they?

It's been answered several times before, but....DCW.

Originally Posted by MaX-D

And where can I get some?

You can't.

Originally Posted by MaX-D

Do they make them in 2.2?

I may have made them in 2.2 at some point, I don't really remember.

Originally Posted by HumboldtEF

Thanks for sharing the suspension tuning run down. Thats not something I ever really test in depth.

[Duuuuuuuude]

Had a busy weekend and didn't make the progress I was hoping to make, but revision #4 is done and I think it's the winner. No modifications needed and it retains all of the factory links. Just gotta run it through the ringer and tweak some of my processes.

Peek-a-boo.

[Turtlejon]

Is there any room for a winch behind that fancy grill? Either a servo winch with a spool, maybe next to the servo? Or an internal servo winch? Even a scale winch hidden somewhere? The way that bumper fits looks like it has a great approach angle, so I’d rather not put a winch out there where it might reduce that angle. It’ll be easy enough to put the receiver somewhere else...

And with the panels off, it looks like we can see a peek of those link risers...
Will my vintage set of risers work? And what about the chassis stiffeners?

[MaX-D]

Originally Posted by Duuuuuuuude

Had a busy weekend and didn't make the progress I was hoping to make, but revision #4 is done and I think it's the winner. No modifications needed and it retains all of the factory links. Just gotta run it through the ringer and tweak some of my processes.



Peek-a-boo.

Are the wheels and tires going to stay?. Those Wheels look sharp. Will the Duratrax deepwoods tires make a reappearance? Those tires look great on that truck

Sent from my LM-G710VM using Tapatalk

[Duuuuuuuude]

Originally Posted by Turtlejon

Is there any room for a winch behind that fancy grill? Either a servo winch with a spool, maybe next to the servo? Or an internal servo winch? Even a scale winch hidden somewhere? The way that bumper fits looks like it has a great approach angle, so I’d rather not put a winch out there where it might reduce that angle. It’ll be easy enough to put the receiver somewhere else...

You'd have to move the rx box. I haven't looked at it very hard but I'm sure a servo winch would easily fit.

Originally Posted by Turtlejon

And with the panels off, it looks like we can see a peek of those link risers...
Will my vintage set of risers work? And what about the chassis stiffeners?

They won't. It's a completely different skidplate. The good news is that this version will be cheaper.

I haven't decided on additional stiffeners yet. Might not hurt, might not be needed. We'll see.

Originally Posted by MaX-D

Are the wheels and tires going to stay?. Those Wheels look sharp. Will the Duratrax deepwoods tires make a reappearance? Those tires look great on that truck

The stock set is just there for testing, and I'm pretty well done with that. The Deepwoods will be back, but honestly they're a bit taller than I like. I'll give them another go though and if they don't pan out, there's a set of well loved Pitbulls standing by.

[Duuuuuuuude]

Not wanting to spend the night in front of the laptop or hovering over my little cnc, I decided to see about losing some altitude. First up was some new, skinnier links to gain a little room for movement. A little bend in the panhard bar got it to clear the axle, but now it bumps up against the servo horn. One step forward, half a step back.



Next was a bit of lowering at all 4 corners.

[GA Dawg]

It definitely looks better down low.

[Duuuuuuuude]

Pulled the bumper off to get a better look, and the panhard rod end get sandwiched between the servo horn and axle truss at full bump. Looks like this is as far as I can go at this point.

While I was in there, I also found out that the rx box is molded into the cage, so it wouldn't be an easy removal for a winch. Nothing a little cutting couldn't cure though.

Originally Posted by GA Dawg

It definitely looks better down low.

It looked cool up high, but I agree. Lower is better IMO.

[Duuuuuuuude]

One more time up the incline board with the new lower stance and it bested the OG version with a 58.2*. Granted, it did take a bit of wheel speed in a race to get to the top before the suspension fully settled, but a win is a win. It's interesting to note that the stock tires found the grip to do it.

Of course the incline board is just a gauge and means little by itself, kinda like Flex Friday. But unlike Flex Friday, it does mean that improvements are being made.

Tomorrow night I'll work on getting the rest of the links replaced and schedule in some drive time later this week.