Shock temp questions...

[Figit090]

I have a few questions, i'll state them briefly to shorten the read...


1) Does shock movement in RC's generate much heat?

2) On the REVO i noticed the left-rear shock is VERY close to the engine; wouldn't this cause excessive shock heat?
If so, wouldn't that make the left rear suspension action much softer and make it handle weird or act assymetrical over bumps and turns?

(what i mean is...wouldn't it make left vs. right turns much different handling-wise?)

[Figit090]

Nobody??

[SavageMan21]

I don't think the shocks generate much heat and it really doesn't affect the handling if the shock is closer to the engine.

~Justin

[maxxamillion]

I agree with you figit-that was one of the [maybe] flaws in the Revo that I noticed also.
In 1/1 racing many shocks have piggybacks or remote resevoirs to cool shock oil. Doesn't appear to be a problem on rc's, but there has got to be a lot of heat between the head & pipe on the Revo.
Nobody has complained of it. And if there was a problem, I would just put one weight heavier oil in them(both).
I'm glad somebody else noticed this...

[Ken448]

if the concern is that great.. not for me... but try to build a heat sheild..

[Figit090]

well i was just curious...because if it didn't make any difference then why the heck would you ever want the extra wieght of a piggyback...

i can't understand how those work anyway, if there's extra fluid in a SEPERATE cylinder, how's that going to cool off the main cylinder? in my mind that fluid would never really move around much, unless there was a hole in the body of the shock leading to the piggyback. can someone enlighten me on that? it never made sence to me. nor did the theory of extra compensating for bumps and jumps with more fluid...unless the oil compresses a lot.

[kitty]

From what I've seen, most monster truck shocks with reservoirs have fake ones. They're just there for looks more than anything else. Even the few that have functioning reservoirs, I seriously doubt that there's much cooling effect to the fluid.

One shock on my Savage is very close to the header. It hasn't become hot enough to do anything to the paint on the spring, nor affect the composite shock body. If it causes any change in handling whatsoever, I wouldn't notice. It's a monster truck and I drive it like it's a rental.

[Ken448]

It's a monster truck and I drive it like it's a rental.

NOW THATS FUNNY!

[thunderbt3]

today's silicone shock oil should be heat resistant, it shouldnt change viscosities when heated, thats one of the main selling points of silicone shock oil.

[Figit090]

NOW THATS FUNNY!

NOW YOU'RE a flippin suck up.... :rolleyes: :p



hehe...jk :D



today's silicone shock oil should be heat resistant, it shouldnt change viscosities when heated, thats one of the main selling points of silicone shock oil.

OOH...i see. Well thanks for clearing that up, i didn't know that.

WOAH WOAH....wait a gosh darn minute!! that can't be true, because i live in a cooler area and last summer i went to a really hot place, and my trucks suspesion was way soft because of the heat. I have traxxas Big bores... if that could make a difference, like expanding/contracting plastic. but anyway, how do you explain how the truck felt so soft and mushy when it was hot? especially with 8 shocks :eek:

[RCMadMatt]

Maybe the heat softened the springs?! The change in altitude? High tide? Lunar pull? :D

Matt

[Figit090]

underground ailien obduction? that ones possible.... or mole people using magnets to pull my truck into the ground for testing.

[RCMadMatt]

I knew there was a purely scientific reason that your suspension was softer than it was before!!! :D

Matt

[MrHorspwer]

if there's extra fluid in a SEPERATE cylinder, how's that going to cool off the main cylinder? in my mind that fluid would never really move around much, unless there was a hole in the body of the shock leading to the piggyback. can someone enlighten me on that?

The fluid does move around... it is a liquid. Simply having the extra fluid allows the heat to dissipate amongst the extra fluid. Think of oil in an oil pan. The more oil that's in there, the more heat in can store without an actual increase in temperature (remember, heat and temperature are not the same thing). Same thing goes for shocks. The more fluid, the more heat it can hold without an increase in temperature.

unless the oil compresses a lot

You cannot compress a fluid.

[Figit090]

oh seriously? wait...what about water, there is oxygen in water and you can compress oxygen mollecules.....

I wasn't thinking when i said oil though, i just kinda was assuming for a moment that all liquids act the same. can't water be compressed? or is the liquid form it's stopping point.

[RCMadMatt]

Water doesn't compress at all. Yes, there's oxygen molecules in the water, but it's not like we're talking about misty air here. :D Have you ever seen the results of regular engines when water is ingested? Not a pretty sight, to be sure. The water gets sucked in, then the piston comes up to compress what it thinks is an air/fuel mixture, only to run into the wall of water. Next thing you know, connecting rods bend and snap, and engine needs some major TLC!!

Matt

[-=ADA$=-]

you can compress fluid but not as much, its hardly noticable

[Figit090]

Ah HA! :D told you! :p


jk, but anyway, wouldn't it have to be because there has to be space between the molecules, if there weren't it wouldn't be a liquid... wouldn't it be somthing weird if there was no space? like...a black hole.......lol ;) i dunno i'm just rambling waiting for school to start... i came to early :rolleyes:

[illbreakit]

As far as the remote resevoir's doin'g anything benificial, they don't. Not unless they are the type that have a foam volume compensator in them. In 1/10th shock's, (read:Tmaxx Style) they are an emulsion type. meaning that there is some air in them to be able to compress when the shock shaft enters the shock body and lowers the internal volume. Now, the resevoir's have a hole that does connect them to the shock body. This in theory would be cool, and work. But, in an emulsion shock, what do you have? Air. And air is likes to go to the highest point. Right where the transfer hole is between the remote res and the shock. Now, the oil can't go back and forth, and it is not making direct contact for heat dissipation. So, it does nothing, other than weigh your truck down and lighten your wallet. That's why I put the Tmaxx res's I got with a used truck up on ebay for sale imediately. There iseless to me, but someone who want's show, there worth alot :D

Oh, and heat does affect the silicone oil, just not to the varing degree that it does mineral oil. That's why most MT makers use 2 shock's per wheel, and Losi has that big one(pretty much equal to 2 Savage shocks for volume). More oil volume, plain and simple. More oil means better heat stability, which makes more consistient performance, especially in those Hr long main's.

[Figit090]

that's dumb.... and it seems like it would be hard to make it without air inside, so thats just stupid, and more stupid that AE put fake ones on their truck... if anyone that saw your truck and knew about real 1:1 trucks would ask if they were real and it would just be embarrasing to say "no...they're fake". why the heck DID AE stick those extra thingys on their shocks... :confused:

[redheat8]

I use Integy piggy shocks on one of my TMaxxes and they work fine, the hole deal about having the piggy back is to transfer the fluid from the tube to the resevore and back to cool the fluid and in combination with a progressive spring on the corners it works great, RED

[dhutch]

today's silicone shock oil should be heat resistant, it shouldnt change viscosities when heated, thats one of the main selling points of silicone shock oil.

yeah, all 100% silicon shock oils should be - most say on,
- ie the AE oil says "will not thin in hot weather or thinken in cold..."
- and the Shumachers oils say "Temp stable, high precision graded..."

[MurcielagoR-GT]

you can compress fluid but not as much, its hardly noticable


You can NOT compress any type of liquid. If you could your car would not have brakes!

Figit: If you check the Traxxas forums they explained the heat issue of the shocks. They found that the heat of the engine was not causing any stress on the rods.

[illbreakit]

I use Integy piggy shocks on one of my TMaxxes and they work fine, the hole deal about having the piggy back is to transfer the fluid from the tube to the resevore and back to cool the fluid and in combination with a progressive spring on the corners it works great, RED

Yes, but when you assembled your shock's with the integy res's on them, you left some air in there, right? You had to orelse the shaft would not go into the shock, because yuo can't compress a liquid. Now, if you have air, and air rises to the top, where is the air in your shock, at the top of the integy res. Now, concidering that the shaft displaces fluid, and compresses the air in the top to compensate, NO FLUID is acctually transfering to the remote res. The reason a real remote res shocl works is because it has a bladder in the res, not unlike 1/8 scale buggy shock's. This bladder has compressed nitrogen on one side, and the shock oil on the other. That way, there IS a fluid connection between the res and the shock.

[redheat8]

Sure there is some air in the shocks they, would not work properly if there wasnt , and yes fluid does get trans. to the res. reguardless of the small amount of air that is left in the shock, RED

[MrHorspwer]

You can NOT compress any type of liquid. If you could your car would not have brakes!

What was said is correct... liquids can be compressed. However, it requires obscene amounts of pressure to do so and the compression is almost immeasurable. For most common discussions and for all praticle purposes, we say liquids cannot be compressed.

Automotive brake systems operate at up to 1600 psi. That won't come close to compressing a liquid. An R/C car shock certainly will not compress a liquid.

A quick link...
http://www.physlink.com/Education/AskExperts/ae15.cfm

[MurcielagoR-GT]

What was said is correct... liquids can be compressed. However, it requires obscene amounts of pressure to do so and the compression is almost immeasurable. For most common discussions and for all praticle purposes, we say liquids cannot be compressed.

Automotive brake systems operate at up to 1600 psi. That won't come close to compressing a liquid. An R/C car shock certainly will not compress a liquid.

A quick link...
http://www.physlink.com/Education/AskExperts/ae15.cfm

Thanks for the link! very interesting! ;)

[Figit090]

Yeah thanks! I see what you mean about it virtually not being possible, but that little bit i had in my mind about the atoms having space between them kept me from agreeing... sorry. lol but ok.. is traxxas shock oil heat resistant/unchanging with heat? if it isn't that could be my problem. i'm using the stuff that came with the truck.

its possible that it was just my imagination, or that the suspension momement free'd up with the heat, because when i then took the truck apart and replaced the shock coverings, i noticed the ball cups were tight, and the heat could have just been making those looser, and the softness was supposed to always be that way.

thanks for all the posts everyone, and sorry for being stubborn! :D