Tamiya Damper Oil

[Malakite]

Hi guys n gals - can anyone let me know if the oil really makes a difference from soft/medium/hard??  I have the upgraded lunchbox suspension however the from coils hardly bounce back - the wheels stay low down - and its a problem when I reverse...so Im wondering if I should be upgrading the damper oil at all?  Any advice would be greatly appreciated - thank you!! 

[Effigy3]

In short, yes the oil can make a huge difference in the characteristics of your rig 

In long, read this

 

[GregM]

Malakite, what exact dampers, springs and oil are you using?

[Flerbizky]

1 hour ago, Effigy3 said:

In short, yes the oil can make a huge difference in the characteristics of your rig 

In long, read this

 

In a Lunchbox, I'm guessing the difference will be very minor (:

[Effigy3]

44 minutes ago, Flerbizky said:

In a Lunchbox, I'm guessing the difference will be very minor (:

Probably true.

[GregM]

Well, true.

Generally speaking, I'd use thin oil and soft springs with the Lunchbox, probably preferring Tamiya's CVA dampers over cheap aftermarket alloy dampers. Also Pintopower's Ampro CW-01 transmission brace:

 

[Malakite]

guys, I got the Tamiya hop up oil damper, but the fronts just drop crazy..when you reverse its awful because the front just always bottoms out onto the tyres (the bodyshell - rubbish!)

[Effigy3]

19 hours ago, Malakite said:

guys, I got the Tamiya hop up oil damper, but the fronts just drop crazy..when you reverse its awful because the front just always bottoms out onto the tyres (the bodyshell - rubbish!)

Could you post a decent resolution image or two of the dampers.  It's really hard to try and trouble shoot sight-unseen.

[Malakite]

20 hours ago, Effigy3 said:

Could you post a decent resolution image or two of the dampers.  It's really hard to try and trouble shoot sight-unseen.

They are just very soft - i.e. they do not return/spring up very well at ALL when the car goes down at the front/when th pressure goes to the front of the car when it reverses - the front end goes down way to easily...

[Kingfisher]

On 8/5/2016 at 6:15 AM, Malakite said:

They are just very soft - i.e. they do not return/spring up very well at ALL when the car goes down at the front/when th pressure goes to the front of the car when it reverses - the front end goes down way to easily...

Is this the shock kit you have?

https://www.tamiyausa.com/product/item.php?product-id=50520

That's the one I put on my Lunchbox. Mine did the same thing as you describe. I originally assembled the shocks with the 3-hole pistons and stiff springs. I changed the piston from the ones with 3 holes, to the ones with 1 hole and added the thicker preload spacers to each front shock. In reverse, mine still sags down low, but it doesn't hit the body and it does return back to normal height when it stops. I feel that a stiffer spring may be needed than what comes with the kit. I have yet to experiment with a thicker oil.

[GregM]

So I guess stiff spings at front and soft ones at the rear should do the trick for the Lunchbox?

I'd also try re-using the regular springs that came with the Lunchbox.

[Kingfisher]

14 hours ago, GregM said:

So I guess stiff spings at front and soft ones at the rear should do the trick for the Lunchbox?

I'd also try re-using the regular springs that came with the Lunchbox.

Yep. Stiff in the front, soft in the rear. Stock springs on the front oil shocks are my next experiment.

[Malakite]

On 8/7/2016 at 7:54 PM, Kingfisher said:

Is this the shock kit you have?

https://www.tamiyausa.com/product/item.php?product-id=50520

That's the one I put on my Lunchbox. Mine did the same thing as you describe. I originally assembled the shocks with the 3-hole pistons and stiff springs. I changed the piston from the ones with 3 holes, to the ones with 1 hole and added the thicker preload spacers to each front shock. In reverse, mine still sags down low, but it doesn't hit the body and it does return back to normal height when it stops. I feel that a stiffer spring may be needed than what comes with the kit. I have yet to experiment with a thicker oil.

Yes thats the one!! Can't remember what 'holes' I used...Need to check that!

[Malakite]

On 8/8/2016 at 0:29 PM, Kingfisher said:

Yep. Stiff in the front, soft in the rear. Stock springs on the front oil shocks are my next experiment.

Wow are they actually harder then? The original springs I mean??..

[Kingfisher]

7 minutes ago, Malakite said:

Wow are they actually harder then? The original springs I mean??..

The original springs are stiffer, but also longer. I compressed mine onto the shock anyways and gave it a try yesterday. No more sagging when reversing, and it feels like it corners better, which makes sense because the front is stiffer. My testing was done in a flat concrete parking lot. At full trigger doing a wide circle, you can see the front tire trying to roll off of the rim. But, I think it's a bit too stiff with the stock spring because it flips over much easier. I know, it's a Lunchbox, but it wasn't as tippy with the softer spring on the front. I'm going to play with the valving of the shocks and see if I can find a happy medium, or possibly even source out some other springs to try.

[Malakite]

3 minutes ago, Kingfisher said:

The original springs are stiffer, but also longer. I compressed mine onto the shock anyways and gave it a try yesterday. No more sagging when reversing, and it feels like it corners better, which makes sense because the front is stiffer. My testing was done in a flat concrete parking lot. At full trigger doing a wide circle, you can see the front tire trying to roll off of the rim. But, I think it's a bit too stiff with the stock spring because it flips over much easier. I know, it's a Lunchbox, but it wasn't as tippy with the softer spring on the front. I'm going to play with the valving of the shocks and see if I can find a happy medium, or possibly even source out some other springs to try.

Wow thats awesome!! My sprigs will be going straight back on then! :-)

[Kingfisher]

12 minutes ago, Malakite said:

Wow thats awesome!! My sprigs will be going straight back on then! :-)

I'm pretty new when it comes to building these. Let me know what you think of the handling after you try it out. I kept the soft springs in the rear on oil shocks and don't see a need to change. 

[Hobbimaster]

I have a white set of Tamiya CVA'a on my blue edition Tamiya lunchbox that look fantastic. They are built per instructions with "soft" damper fluid. They work well going forward, but in reverse, the front arms dive like a submarine into the shell. I just chalk it up to the design of the front arms really that cant handle the weight shift from the rear axle when going into reverse.

[GregM]

5 hours ago, Hobbimaster said:

They work well going forward, but in reverse, the front arms dive like a submarine into the shell.

This behaviour is normal for this type of simple swing-arm suspension and is aggravated by the big tires. The DT-01 Mad Bull does the same.

If you do the double-wishbone-suspension mod, either using FX-10 parts or Pintopowers custom CW-01 parts (link in my post further above), you should be able to remedy this.