Stein Tumert

We have used this "tuning option" (drill hole in caps) at least since 2009 or 2010...

ic-racer

To behave like a full-size automobile shock the bladder has to have a lot of pressure. To maximize the pressure I use a foam pellet and put the lid on the shock with the piston all the way out. Like #1 in my animated GIF above. So, yes the shaft sticks all the way out when done. If it does not then I have a problem with the build and not enough pressure in the bladder.
I then take the R and L shocks and press them into each other, shaft-to-shaft. This lets me see if they both have the same pressure in the bladder. If they both reach full compression at the same time, the bladder pressures are equal.

In #4 there is almost no pressure in the bladder, as if there were a hole in the top of the shock. Again with model cars maybe foamy can be faster if everything else is set up around doing it that way. I have an engineering background so I have to build my shocks like #1 above or else I lose sleep...

190mph

iTrader: (12)

Yeah interesting. The older Tamiya shocks used the Urethane Foam pellet on top of the bladder and under the shock cap, but now not called for but there must of been a change in the shock cap design to hold down the bladder.

I guess all automotive shocks that are not front strut with spring have full rebound and shocks mostly are like gas charged. I remember changing my shocks on my Silverado truck to the Rancho ones and they came compressed enough in a long strong twist tie setup where you install on the bottom mount and line up the top mount and undo the twist tie setup as it goes out and hard to push back in with any manual labor.

190mph

iTrader: (12)

Guys for different one piece suspension mounts at the front of the fronts and rear of the rears is it the TB-03 mounts that are the ones?

Skiddins

So you're building your shocks with 100% rebound?

You'll notice from team driver setups from any manufacturer that 100% is very rarely, if ever, used.
Have you tried running shocks with limited and zero rebound?
It might cause you some insomnia, but will improve your lap times as well

subaru73

iTrader: (42)

Yes those are the ones you need

niznai

Yeah, I did that too, but it's hit and miss and very fiddly.

I also noticed with most shocks when the piston is at the top of its stroke it pushes against the bladder (don't know about modern Xray). This is with the bottom spring perch installed, and the shock compressed all the way. I think this is a shortcoming of the design, but in use the shock should never compress that much. That said, I would still like shock shafts a bit shorter (of course one can use some shims to limit travel upwards).

tobyzhang

iTrader: (15)

This is very interesting to me as well because monotube shock design employed by likes of Bilstein use high pressure on seperate gas chamber to make sure the oil stays consistent without aeration foaming. But all top level RC racers tell people to build shocks with close to 0 rebound as possible (at least from what TRF guys say that in video they release about it). What I suspect is since RC shocks do not have the intricate washer loaded spring valves to control precise bound and rebound dampening, plus the inability to consistently pressurize the gas chamber, they opted of a vacuum type volume compensation to get greater rebound damping than bound damping. And since this is the fastest way to get air into the oil, they have to rebuild the shocks very frequently to stay consistent. It would be interesting if someone did indeed design a scaled monotube pressurized shock for RC application with adjustable bound and rebound valving. I assume if someone did it the shock will cost probably more than the entire chassis...

190mph

iTrader: (12)

I think inconsistency is also introduced capping these shocks, you put the bladder on and squeeze oil out, try to use tissue paper to absorb up some oil, then rest the plastic top mount cap on the bladder and then screw on the outer ring like cap to tighten that down, but you fiddle with the threading and disturb the bladder, things like that.

I don't think it would be too costly to come up with a different design.

I actually almost would prefer to fill and bleed somehow the shock on the bottom side if there is a way. The small bottom cap would be easier to deal with.

ic-racer

Yes, if one is building a DeCarbon/Bilstein monotube gas shock, by design it needs to be pressurized to prevent foaming or air entry around the shaft. If you don't build it pressurized you don't get the anti-foaming benefit of the design. Also, If you don't build it pressurized, on full rebound the pressure in the bladder is actually negative with respect to atmospheric and it is functioning like a concentric two-chamber shock whereby the chambers are separated by the diaphragm rather than separated in the two concentric tubes. Full size non-gas pressurized shocks have been around like that for years but they have a tendency to foam so the DeCarbon/Bilstein gas shock style is favored in many full-size automobile or motorcycle racing settings.

For RC cars in racing settings maybe foamy is better. In fact the 'aeration shock' is based on that.

ic-racer

I didn't mention that the reason I started building my shocks with gas pressurization is that when 1/8 on-road racing a few years ago I built my shocks without pressurization and had to re-build them every race due to foaming and air entry around the shaft. When they are pressurized air is less likely to get in around the shaft and foaming is less likely. So, when I switched to 1/10 electric on road I still build my shocks pressurized. Thought I'd like to try the aeration shocks and see how they compare.

Qatmix

Look what I and a few others have been working on in the lab.
http://www.thercracer.com/2016/03/ta...nd-blocks.html

3D printing is pretty smart

190mph

iTrader: (12)

Nice work. Is that a F style Separate Suspension mount for a parallel arms situation or something more narrow when putting the actual F block in the very front for a toe out type suspension which I find most have on their setups in general and a local T4 racer says offers more stability?

Simmi

I went yesterday for the first time my 419 with the short shock and the short shock towers. Had no tracksion and my rear overtook me when relent.

Could change what I wanted but nothing helped.

The worst thing I ever had on Track.

Become put everything on top.
The worst Tamiya I ever drove

Johnn27

iTrader: (89)

What front springs were you using? Did you have a front sway bar?
When I drove that set up on my 417 Raceberry conversion I experienced the same handling characteristics, it required a really hard spring up front.