Shock placement on a-arm. Very odd, makes me wonder…

[Dan B.]

600+ pages.

View attachment 364106

Ok, fine. I guess when you put it that way.
I’ll ask for this for Father’s Day. My daughters can go in together and it won’t be so bad. If I get it y’all might not see me here for awhile though. Probably cause for celebration for some…

 

[Steve B in Vegas]

Well,

$85 for that amount of correct / high quality info is a crazy good deal. You won't use all of the book, but you will find many, many answers to questions you didn't know to even ask. My copy has sticky flags on some pages with notes and highlighted sections. Helped me a lot when setting up the suspension in a few of our rock racers and my Mojave 6s. I absolutely love the math and formulas included with the book.

 

[Dan B.]

I keep telling my partner to start fabricating RC parts from magnesium. We already machine mg in our day job, so it's really not a big step. Wonder how much we could charge....

Yeah, you sold me on it. I want it. If I don’t get it for Father’s Day I’ll just buy it. But I already sent both of my kids a link, so I’m hopeful.

 

[LibertyMKiii]

That is 100% correct. Since you made those points I’m now trying to talk my own way through your points. The shock does indeed have less travel per degree of upward motion of the a-arm the farther it is mounted outside on the bottom. However, it is still less easily compressed/manipulated to that point of compression, right? So if we were to introduce a variable rate spring the amount of total compression would indeed become present in the equation, even while agreed that it would be more easily compressed the further inboard the shock was mounted on the lower a-arm.
I removed the black Perfect Pass springs (even though they look awesome) because the windings were too soft and I could no longer tune with absolute coil bind as I’m able to do easily with those repurposed Redondo Beach titanium valve springs which are, BTW, freaking awesome.
Long story short, regardless of the spring weight or type (linear or progressive) the spring is more easily compressed the closer it is mounted to the pivot point of the lower a-arms. So yeah.
To simplify, whatever setup you’re running, if you mount your shock farther to the outside on the lower a-arm the harder your suspension will be. Not softer.

I'll take your word for it and certainly believe its true for this scenario because the shock travel is short and the changes between those holes isnt too extreme.
I could imagine more extreme scenarios where moving the shock further out towards the wheel with enough shock angle could reduce the springs function significantly.

 

[Steve B in Vegas]

Ooooooh, snap..! I'm stoked for you. It gets into the bug dust of bug dust, but creates such an excellent foundation to work from...! I wish there was a version of this oriented towards off road trucks and rock crawlers.

Also, while I'm not a street guy, here is a video from someone who really knows what they are talking about and can break down some of these complicated ideas.

Welcome to the world of math..! Yeah..!!

 

[Dan B.]

I'll take your word for it and certainly believe its true for this scenario because the shock travel is short and the changes between those holes isnt too extreme.
I could imagine more extreme scenarios where moving the shock further out towards the wheel with enough shock angle could reduce the springs function significantly.

Most definitely agree. The farther out (say a much longer a-arm) the less the spring will compress and would be working much harder for any effect.
On the car I’m building now I’m using those ultra stiff titanium Redondo Beach springs on modified shocks mounted as far outboard as possible with the upper mounting point being as close to the center as possible. They’re lying down. The shocks are running drilled internal discs with 90w fluid. They have both internal and external limiters on 6mm shafts. The internal limiters are actually redundant though, as the travel is limited with absolute coil bind. They are freaking stiff man! Very hard to manually compress even over the very short distance they have to move before coil bind. But marginally better than eliminating the shocks altogether and running struts.

 

[LibertyMKiii]

Most definitely agree. The farther out (say a much longer a-arm) the less the spring will compress and would be working much harder for any effect.
On the car I’m building now I’m using those ultra stiff titanium Redondo Beach springs on modified shocks mounted as far outboard as possible with the upper mounting point being as close to the center as possible. They’re lying down. The shocks are running drilled internal discs with 90w fluid. They have both internal and external limiters on 6mm shafts. The internal limiters are actually redundant though, as the travel is limited with absolute coil bind. They are freaking stiff man! Very hard to manually compress even over the very short distance they have to move before coil bind. But marginally better than eliminating the shocks altogether and running struts.

Yeah I am a believer of having some small amount of travel. It helps absorb the little vibrations at least.
My VTE2 had only 2-3 mm travel in the rear per McCoy's direction and it was dialed.... never crashed so that made me a believer.

 

[Dan B.]

Ooooooh, snap..! I'm stoked for you. It gets into the bug dust of bug dust, but creates such an excellent foundation to work from...! I wish there was a version of this oriented towards off road trucks and rock crawlers.

Also, while I'm not a street guy, here is a video from someone who really knows what they are talking about and can break down some of these complicated ideas.

Welcome to the world of math..! Yeah..!!

I’ve been watching that video you linked to. I’m digging it man, I just learned some stuff quick! I’ll be checking more of his stuff out for sure. I’m not a drag race guy, but it’s some really useful information.

 

[Garcbomber]

Have you guys never purposedly overfilled the bladder cap shocks with heavy fluid? It'll stay rock hard, then just let out a bit from the weep hole to get the right amount of travel you're seeking. They'll stay fully extended so just cut and die thread the end to the ride height you desire.

Agreed, I definitely wouldn't replace coil overs with solid upper links, maybe a robust/rigid plastic that allows a bit of deflection.

 

[Dan B.]

Have you guys never purposedly overfilled the bladder cap shocks with heavy fluid? It'll stay rock hard, then just let out a bit from the weep hole to get the right amount of travel you're seeking.

That works, but if you blow a shock seal with all that pressure your shock turns to mush. I’ll do it with limiters, and/or coil bind. I go too crazy with shock setup, probably. My mantra is: emulsion setups blow goats and you need to learn to tune your rebound perfectly with bladder setups. I love it.

 

[Garcbomber]

That works, but if you blow a shock seal with all that pressure your shock turns to mush. I’ll do it with limiters, and/or coil bind. I go too crazy with shock setup, probably. My mantra is: emulsion setups blow goats and you need to learn to tune your rebound perfectly with bladder setups. I love it.

Yep, I presume you all rebuild shocks with fresh fluids/o-rings after every bash/race too. Right!?

 

[Dan B.]

Yep, I presume you all rebuild shocks with fresh fluids/o-rings after every bash/race too. Right!?

No, almost never. Once I set them up I never touch them again unless I see signs of leakage. (From the shocks, not me. I leak frequently but it doesn’t really seem to impact too much.)

 

[Dan B.]

Ooooooh, snap..! I'm stoked for you. It gets into the bug dust of bug dust, but creates such an excellent foundation to work from...! I wish there was a version of this oriented towards off road trucks and rock crawlers.

Also, while I'm not a street guy, here is a video from someone who really knows what they are talking about and can break down some of these complicated ideas.

Welcome to the world of math..! Yeah..!!

Dude, I’ve been watching that guy for most of the morning. He’s fantastic and actually makes the trig easy to understand. I SO wish he was a road racer. I’ve never seen anyone who comes close to this guy in a road racing explanation of setup. Most of the road racers I know are stuck up, secretive d-bags. There were some exceptions, but not too many. Thanks again for the link to this guy, and if anyone reading this is a drag dude, then you must check him out. Awesome.

 

[Steve B in Vegas]

Dude, I’ve been watching that guy for most of the morning. He’s fantastic and actually makes the trig easy to understand. I SO wish he was a road racer. I’ve never seen anyone who comes close to this guy in a road racing explanation of setup. Most of the road racers I know are stuck up, secretive d-bags. There were some exceptions, but not too many. Thanks again for the link to this guy, and if anyone reading this is a drag dude, then you must check him out. Awesome.

I'm pleased you are enjoying the videos. I have studied him close in that his link discussion is quite helpful for setting up crawlers when you're attacking steep lines. I'll take it a step further and say that as a crawler, if you do not have a basic understanding of his 4 link discussion, you'll struggle to get your crawler set up correctly.

I'm sure there are road racers out there with this stuff, just gotta dig around a bit. I've also used his and that book's help for setting up my Mojave 6s for grass racing, looking to get the best handling in the corners as possible. The 1/8 buggy guys pretty much have that figured out, but every bit of information can be of use, as long as the source knows what they are talking about ( hence the root of this thread ). Of course, without truly valved shocks, we can only do so much.

s.

 

[Dan B.]

I'm pleased you are enjoying the videos. I have studied him close in that his link discussion is quite helpful for setting up crawlers when you're attacking steep lines. I'll take it a step further and say that as a crawler, if you do not have a basic understanding of his 4 link discussion, you'll struggle to get your crawler set up correctly.

I'm sure there are road racers out there with this stuff, just gotta dig around a bit. I've also used his and that book's help for setting up my Mojave 6s for grass racing, looking to get the best handling in the corners as possible. The 1/8 buggy guys pretty much have that figured out, but every bit of information can be of use, as long as the source knows what they are talking about ( hence the root of this thread ). Of course, without truly valved shocks, we can only do so much.

s.

Don’t get me started. I’ve said before, if we could call Bilstein Motorsport and order a set of fully spec’d shocks with whatever we want for compression and rebound it would be awesome. I actually saw some RC remote reservoir adjustable damping shocks once but IIRC I think they were like $800.00 a set or something crazy like that.

 

[GamwToInsomnia.gr]

I keep telling my partner to start fabricating RC parts from magnesium. We already machine mg in our day job, so it's really not a big step. Wonder how much we could charge....

Is Magnesium, lighet than alu and carbon?
Stronger?