DT-02 is this sitting too low?

[alvinlwh 5895]

Just checking over my freshly finished Holiday Buggy chassis. It seem that the springs are not pushing the car back to full height? This only has a 380 motor and doesn't even have its body on yet. I used the DT-03 shocks set, which is the one with the fixed metal pistons. I did not build it completely according to instructions but matched in length and movement range to the stop friction shocks. 

Rear lifted up. 

And released from that height. 

Front, released from the same height. 

Basically, I did not slam it down from a great height but dropped front or rear from about an inch up and they did not return to their fully extended position. 

Should I install some preload onto it? 

One further question is, the bottom hits the deck before the shocks hit their stop, should I install some spacers to stop the bottom from bottoming out? 

[Silver-Can 402]

You could try adding some collars to the top of the shock body (they're typically 'c' shaped when looked at from above) and they just clip in below the shock cap and above the spring. This is to increase ride height but will not do anything to 'firm up' the shock action. Did you use the standard yellow 400 weight tamiya oil? You could try heavier/thicker oil if available, or try different inserts in the shocks (the little circular bit at the top of the shock shaft with a couple of small holes in). More holes = less resistance and vice versa.

In terms of bottoming out, it is preferable for the car to bottom out before you run out of shock travel as otherwise you put strain on the shock tower and the shock tower will break before the bottom of your car (in most cases)

Edit: just to add you could try using the springs from the friction shocks if they'll fit. They might be a bit stiffer than the dt03 ones.

[alvinlwh 5895]

49 minutes ago, Silver-Can said:

You could try adding some collars to the top of the shock body (they're typically 'c' shaped when looked at from above) and they just clip in below the shock cap and above the spring. This is to increase ride height but will not do anything to 'firm up' the shock action. Did you use the standard yellow 400 weight tamiya oil? You could try heavier/thicker oil if available, or try different inserts in the shocks (the little circular bit at the top of the shock shaft with a couple of small holes in). More holes = less resistance and vice versa.

In terms of bottoming out, it is preferable for the car to bottom out before you run out of shock travel as otherwise you put strain on the shock tower and the shock tower will break before the bottom of your car (in most cases)

Edit: just to add you could try using the springs from the friction shocks if they'll fit. They might be a bit stiffer than the dt03 ones.

Yes, I have a bunch of preload collars I can try.

Yes, I used the 400 oil but also have the medium oil set. Soft for this car might be a good thing as it is meant to be a beach runner? Will confirm after some test runs.

No, holes adjustment is not an option as this is the fixed metal piston set. In theory, the shaft can be changed to normal ones, but the cost of normal shafts are nearly the cost of a set of new CVAs.

Thanks for the info about bottoming out, I will leave the travel as it is.

The springs from the friction shocks are significantly shorter than this and will probably need more than just one preshock collar.

 

[Silver-Can 402]

Cool - yeah, I would try adding the preloaded collars first as it will give you more ground clearance (and it's the quickest/easiest thing to try) and then just see how it rides on your chosen surfaces and then go from there.

You're right in that it is meant as a beach runner (and I personally prefer softer suspension) and with a 380 motor, rear end squat under power shouldn't be too much of an issue i wouldn't have thought. Just see how she handles on the corners and bumps and if needs be, add some thicker medium oil to maintain composure. 👍

[SlideWRX 785]

The *rear* CVA's in the DT-03 get a ~6mm spacer, just above the bottom spring perch.  That makes the shock bottom out before the body does, although it is very close.  Doesn't affect ride height.  Technically, you could put the spacer *under* the spring perch, and also get some spring preload too.

It is ok, and good for the shock to stay a little compressed at ride height.  It doesn't need to extend all the way back up.

[alvinlwh 5895]

16 minutes ago, SlideWRX said:

 Technically, you could put the spacer *under* the spring perch, and also get some spring preload too.

Actually, I was thinking of doing that. Will give it a shot. However, how about what silver-can said about bottoming out the chassis is kinder on the shock towers ? 

[Oh How Original 126]

I would just add some preload collars too, either that or get some CVAs or other aftermarket shocks, the stock ones aren't fantastic.

Or stiffer springs all together.

[SlideWRX 785]

48 minutes ago, alvinlwh said:

Actually, I was thinking of doing that. Will give it a shot. However, how about what silver-can said about bottoming out the chassis is kinder on the shock towers ? 

It would be kinder on the shock towers, yes.  The rear chassis for your DT-02 looks a little more stout that the DT-03, so more landings on the chassis is ok.  My DT-03 still hits the chassis under full shock compression too.

[alvinlwh 5895]

2 hours ago, Oh How Original said:

either that or get some CVAs or other aftermarket shocks, the stock ones aren't fantastic.

Or stiffer springs all together.

They are aftermarket, 54567 to be specific. Stocks for this car are blue colored. 

Unfortunately 53832 from PJ is sold out and they cost stupid money in the UK. 

[alvinlwh 5895]

Update:

I removed the 6mm spacer from the inside and placed a 7mm on the outside as @SlideWRX suggested, under the spring stopper. I also replaced the hop up set spring with the kit stock springs and used the 4mm (thickest) preload collar. Total 11mm of preload is required as the kit springs are much shorter. This just about allow the shock to stretch out fully but may not work well as the stock springs are very slightly wider so may slip out of the spring stoppers. Only proper hard test run will tell.

#400 oil is replaced with #700. Might be too thick. Again, need some good test runs. 

Chassis will still bottom out, just. 

Anyway, now, dropped from twice the original test height. Before and after.

[whahooo 465]

@alvinlwh

Thanks for the Link.
What Oil would you recommend for the DT-02? Is there any "general Oil weight suggetion thread"?
I know that you can`t tell what oil will fit that chassis on that surface/Track... It depends on your Shocks, your Springs, your Pistons, your Track, your Batterytype, etc...

BUT a lot of people use the standard CVAs with 3 hole Pistons, so you can roughly say what is a general good setup for Tamiya Models or fun on Offroad or Onroad use.

[alvinlwh 5895]

7 hours ago, whahooo said:

@alvinlwh

Thanks for the Link.
What Oil would you recommend for the DT-02? Is there any "general Oil weight suggetion thread"?
I know that you can`t tell what oil will fit that chassis on that surface/Track... It depends on your Shocks, your Springs, your Pistons, your Track, your Batterytype, etc...

BUT a lot of people use the standard CVAs with 3 hole Pistons, so you can roughly say what is a general good setup for Tamiya Models or fun on Offroad or Onroad use.

I used #400 front and #700 rear with stock springs on DT-03 CVA set (so no piston holes) and that works out good for me. I have the #800 - #1000 coming so I have the option of a even wider range in the future. It is mainly a case of trial and error. I used to only use the standard yellow #400 oil and only started experimenting now. Another example is I changed the front of my Thunder Dragon to #700 and 1 hole as it was suggested to cure my traction roll problem and that car was great after. 

[BuggyDad 4474]

I've been trying a few things out too, and have had some success with aiming for a slightly lower ride height, which for me has meant taking out all the preload collars, setting the rear spring lower stop back below the spacer (so now there's a little free up and down play in the spring with the wheels off the ground) and using the outer hole for lower front damper mount (still inner at the back). I have slightly harder springs and 600 oil in the rear, stock springs and 400 in the front. My lower arms settle to pretty much dead level now.

I suspect mine is bottoming out a fair bit but is that an issue?

I had started off looking for more ground clearance than this but my car was so inclined to grip roll once I'd got all the camber, toe etc angles sorted and on good tyres that I set about bringing the centre of gravity down, to good effect. I could also achieve similar with an increased track width, but I struggle to achieve that at the moment with wheel nuts that tend to come loose on some wheels because there's no wriggle room in axle length.

[alvinlwh 5895]

4 hours ago, BuggyDad said:

 I could also achieve similar with an increased track width, but I struggle to achieve that at the moment with wheel nuts that tend to come loose on some wheels because there's no wriggle room in axle length.

Some suggestions here. 

 

[whahooo 465]

10 hours ago, BuggyDad said:

I had started off looking for more ground clearance than this but my car was so inclined to grip roll

I akso was thinking about putting longer Rodends on the Ends of my cheap Alu Shocks. Sadly i don't know what Threadsize they should have, because i don't have the right tool to measure it by hand. M2 m2.5 m3 ?

This would help the bottoming out, but it would push the rolling.....

But maybe the Stabilizer i had installed in the Back will help, i could put the blue ine in....

[BuggyDad 4474]

7 hours ago, alvinlwh said:

Some suggestions here. 

 

Ah. Thanks. I popped a question on there. I think I'll try some serrated ones. 

[BuggyDad 4474]

1 hour ago, whahooo said:

I akso was thinking about putting longer Rodends on the Ends of my cheap Alu Shocks. Sadly i don't know what Threadsize they should have, because i don't have the right tool to measure it by hand. M2 m2.5 m3 ?

This would help the bottoming out, but it would push the rolling.....

But maybe the Stabilizer i had installed in the Back will help, i could put the blue ine in....

Do you think a rear stabiliser bar will help reduce grip roll? I have the parts for this so will give it a try. Maybe front too?

To be honest I don't think my car is terrible on this front now, I'm asking a lot of it. The grass is oddly dry for december and pretty grippy. But it's fun chasing improvements. 

[whahooo 465]

11 hours ago, BuggyDad said:

Do you think a rear stabiliser bar will help reduce grip roll? I have the parts for this so will give it a try. Maybe front too?

I don`t know....

On the DT-03 the People say "don`t bother with Stabilizers" and "they are Sluggush" but most of the People don`t install them right
The Manual don`t show the little Mudscrew that holds the rear Stabilizer so it floats freely around.

 

On the DT-02 i can say that it definetly improves the "roll". I have a DT-02 "Scorcher" with a strong speedy Motor (super Stock BZ?) and on Tarmac you see how horrible it rolls when cornering. It`s because i installed the shocks a long as possible, so the Car sits very high and has al lot of Sag (soft setting)....
In that Car i installed Stabilizers in the Front and the rear, i think i installed the soft red ones and they definetly help with the roll. Ididn`t installed the blue ones becaus i thought they will reduce the "Offroadines".

[BuggyDad 4474]

1 hour ago, whahooo said:

The Manual don`t show the little Mudscrew that holds the rear Stabilizer so it floats freely around.

Ooh. Tell me more. I fitted my rear one as per the manual and it's floating about all over the place. What am I missing? There are two unused holes in the piece that goes over the Stabilizer but no spare hardware in the pack. 

[whahooo 465]

Here is the Post:

 

There are 2 little red Points marked in the Manual. There you have to screw in 2 Grubscrews.

I did it and now the Sway Bar Works.

 

I have to see if you have the same Option with a DT02.

 

I also purchased the Hard Shockoil Set from Tamiya and will put the thinnes of the Hard Oils in the Back of the DT02 and DT03.

 

[BuggyDad 4474]

31 minutes ago, whahooo said:

Here is the Post:

 

There are 2 little red Points marked in the Manual. There you have to screw in 2 Grubscrews.

I did it and now the Sway Bar Works.

 

I have to see if you have the same Option with a DT02.

 

I also purchased the Hard Shockoil Set from Tamiya and will put the thinnes of the Hard Oils in the Back of the DT02 and DT03.

 

Ah ha! Yeah I did wonder. 

Done. My pack didn't come with extra grub screws for this. I have some longer ones though so have cut them down just right. There may also be clearance enough for a small screw head in the recess left by the chassis. 

Are you running your sway bar in conjunction with anything to slow your diff down? I think if I'm fitting a sway bar I may have to do something a bit more about the free spinning diff to take care of a more often lifted inside wheel with the rear sway bar, and/or fit the front one to go with it. I built my diff up using some red grease I'd seen compared to AW grease but now I have some AW grease I see that in reality the red stuff is nothing of the sort, just a normal consistency grease, and it makes little difference. Unfortunately my AW grease is just a dollop that came with some cv joints, not enough for a diff. Maybe I'll get some putty. 

[whahooo 465]

I always run miy diffs completly free.

The only cars that use a stiffer Diff are using Ball Diffs.

At some point i have to stiffen all of my diffs and change the aluminium Pinoins for some Steel ones. But i dont use my Cars very often, so i never botherd with the research what car needs what Pinion size.....

Also i use motors that arent as powerful as the brushless ones that a lot of people like to use.

[alvinlwh 5895]

48 minutes ago, whahooo said:

Also i use motors that arent as powerful as the brushless ones that a lot of people like to use.

TBH brushless power don't seem to be what some fans make them out to be. A few months back, someone told me that a 21.5t will beat my TZ "easily". So I went and ordered a 17.5t. Even better than a 21.5t right? No, it did not beat my TZ out of the box, it is just slightly better than a silver can, weaker than a TT. Sure, one can screw around with turbo, timing, or whatever, but that is not quite "easily" anymore. 

And then there is another fan that quoted brushless power at 8.4v, which for a while seems that they are more powerful. And then I realised that brushed motors numbers are quoted at 7.2v. So kv to kv, my TZ are still more powerful OOB, with zero screwing around, than the 17.5t.

[BuggyDad 4474]

Interesting. I'd say our 17.5t is faster than our TT, but we didn't compare them side by side. 

[whahooo 465]

The Super Stock motors are very good 23T motors.

Nany People only see the Turns.....

 

A super Stoch 23T motor easily beats an Absima 19T thrust spec motor in rpm and torque.