sosidge 624 Posted April 13, 2022 On 4/11/2022 at 9:16 AM, ThunderDragonCy said: It will be to do with the longer stroke on the dynastorm. Sticking with inch measurements, if your dyna front shock has 1 1/4" stroke (approx 32mm), the force exerted by the spring at bottom out is 1 1/4 * 1.7 = 2.125lb. Modern shocks are shorter stroke. Let's assume 5/8" (around 16mm). At 3.8lb/in, these springs will exert a force of 3.8 * 5/8 = 2.375lb at bottom out. So, a modern buggy does have a stiffer front spring, but not by as much as you think. Also, modern buggies are mid motor with much more forward weight bais, and also run lower ride height on much higher grip surfaces, all of which require much stiffer setup. Tamiya TRF spring rates are listed on the petitrc buggy spring chart https://site.petitrc.com/reglages/UniversalSpringChart.htm The tamiya red and blue springs are from the TRF501X set. The TRF201 springs are softer, marked green, brown and black. Tamiya red is 3.3lb and blue is 3.8 according to this chart. It's not about the stroke, fundamentally what matters is the wheel rate, which is a product of the spring rate and the mounting position of the damper. You've identified a few of the other key reasons for the difference though (weight distribution and grip levels). Bear in mind that we are comparing a 30 year old buggy that was not a racing success against brand new buggies that are winning world championships. Tamiya aren't completely thoughtless when they put springs in a kit, but they will have built the Dynastorm to be easy to drive in the conditions of the time. In Japan, this would be rough, loose dirt tracks, with slow motors and no big jumps. Share this post Link to post Share on other sites
StueyS 41 Posted April 17, 2022 Hi all. I have the DF-03 damper set 53926, and I am trying to find the part number for the rear piston rod (long). It is not in the instructions, can anyone help please? Share this post Link to post Share on other sites
taffer 946 Posted April 17, 2022 3 hours ago, StueyS said: Hi all. I have the DF-03 damper set 53926, and I am trying to find the part number for the rear piston rod (long). It is not in the instructions, can anyone help please? 9805917 Maybe? It's the piston rod from 50520 CVA set Share this post Link to post Share on other sites
Kol__ 3377 Posted April 17, 2022 3 hours ago, StueyS said: Hi all. I have the DF-03 damper set 53926, and I am trying to find the part number for the rear piston rod (long). It is not in the instructions, can anyone help please? If you download the manual from the 4wd section of the Tamiya website, it has the part numbers at the back - https://www.tamiya.com/english/rc/manuals.htm I believe @taffer is right on the part number there as well. 1 Share this post Link to post Share on other sites
StueyS 41 Posted April 17, 2022 I have managed to find it in the DF-03MS manual, 19080876. Finding the parts is proving harder! Thanks for the help :-) Share this post Link to post Share on other sites
Kol__ 3377 Posted April 17, 2022 The DF-03 Dark Impact manual lists it as '9805917' as @taffer suggested Share this post Link to post Share on other sites
StueyS 41 Posted April 17, 2022 3 minutes ago, Kol__ said: The DF-03 Dark Impact manual lists it as '9805917' as @taffer suggested The MS version has the Aluminium shocks which are what I have on my Boomerwig, so thats the version I was after if possible. 9805917 may work, but I don't know the length of them. Share this post Link to post Share on other sites
Kol__ 3377 Posted April 17, 2022 4 minutes ago, StueyS said: The MS version has the Aluminium shocks which are what I have on my Boomerwig, so thats the version I was after if possible. 9805917 may work, but I don't know the length of them. Oh I get you. I have a set here, I can measure for you, hold on a mo... Share this post Link to post Share on other sites
Kol__ 3377 Posted April 17, 2022 9805917 - 46mm total length. Pic attached so you can compare the threaded area as well... Share this post Link to post Share on other sites
StueyS 41 Posted April 17, 2022 12 minutes ago, Kol__ said: 9805917 - 46mm total length. Pic attached so you can compare the threaded area as well... Thats great thank you 🙂 Share this post Link to post Share on other sites
ThunderDragonCy 7779 Posted April 18, 2022 14 hours ago, StueyS said: Thats great thank you 🙂 I have a brand new unused set of 9805917 to sell if you need some. Drop me a PM if you're interested Share this post Link to post Share on other sites
Jonathon Gillham 4595 Posted July 11, 2022 I've had a read through this thread and either missed it or its not here. Does anyone know the difference between DF03 dampers 53926 and the newer DF03/TT02B 54993? I assume both would fit a DB01. Just wondering if there is any difference or is it more a rebrand as DF03 arent that common anymore so they are calling it a TT02B damper? Share this post Link to post Share on other sites
Rvl 2 16 Posted July 14, 2022 I have a few of these piston rods but have the problem the thread rips up the o- ring I just got some new ones On 4/18/2022 at 5:10 AM, Kol__ said: 9805917 Share this post Link to post Share on other sites
WillyChang 1812 Posted July 15, 2022 1 hour ago, Rvl 2 said: thread rips up the o- ring do you prelube the rubber? I use greenslime Share this post Link to post Share on other sites
Juls1 1653 Posted July 15, 2022 On 7/11/2022 at 4:50 PM, Jonathon Gillham said: I've had a read through this thread and either missed it or its not here. Does anyone know the difference between DF03 dampers 53926 and the newer DF03/TT02B 54993? I assume both would fit a DB01. Just wondering if there is any difference or is it more a rebrand as DF03 arent that common anymore so they are calling it a TT02B damper? I’ve got the new set here, will add them to the thread in due course. As far as I can see they are fairly similar I think tamiya changed them so they used more universal parts. (Top/bottom cap etc) 1 Share this post Link to post Share on other sites
Kol__ 3377 Posted July 15, 2022 7 hours ago, Rvl 2 said: I have a few of these piston rods but have the problem the thread rips up the o- ring Really? it's just a standard 3mm thread I believe, I think all Tamiya piston rods run the same type of thread. As mentioned above, the o-rings should be lubed before sliding onto the rod, either damper oil or shock grease. Maybe that would help prevent that issue for you? Share this post Link to post Share on other sites
Rvl 2 16 Posted July 15, 2022 The extended threads chews up the o-ring Share this post Link to post Share on other sites
Juls1 1653 Posted July 15, 2022 46 minutes ago, Rvl 2 said: The extended threads chews up the o-ring When you put the shaft through the shock body, you have the lower seal cap loose right? Then re tighten after the shaft is through? I tend to put the shaft through the body, then slide the o rings up the shaft then the cap and do it up. I generally used team associated green slime on the shaft during assembly, but if I don’t have that, then dabbing the threaded section in shock oil does a similar job. I’ve never had problems with the thread trashing the o ring myself, so not sure what your doing to cause that 🤔 clean up the whole shock with isopropyl alcohol after assembly. Juls Share this post Link to post Share on other sites
SlideWRX 760 Posted July 15, 2022 2 hours ago, Rvl 2 said: The extended threads chews up the o-ring Are you talking during assembly or in operation? With the spring seat on, very little thread show above that. Put the spring seat on, the cap that holds the o-rings in place, and then see how much thread protrudes into the o-ring area. I could see the shoulder where it transitions to thread being an issue if you often bottom out the shock. If it is during assembly, wrap the threads in tape before sliding it through the o-rings. Share this post Link to post Share on other sites
Rvl 2 16 Posted July 15, 2022 2 hours ago, SlideWRX said: Are you talking during assembly or in operation? With the spring seat on, very little thread show above that. Put the spring seat on, the cap that holds the o-rings in place, and then see how much thread protrudes into the o-ring area. I could see the shoulder where it transitions to thread being an issue if you often bottom out the shock. If it is during assembly, wrap the threads in tape before sliding it through the o-rings. In operation , even with the spring seat it hits the o-ring. If I add a spacer it reduces my stroke. My front stroke is about 20mm and rear is 34mm on my tt02b Share this post Link to post Share on other sites
WillyChang 1812 Posted July 16, 2022 Dunno where you got shock shafts with such long threads... are they from earlier CVA era where T put a 3mm flanged nut on the shaft before the bottom spring retainer eyelet? Share this post Link to post Share on other sites
Juhunio 6828 Posted July 17, 2022 I'm struggling with a set of CVA dampers at the moment; no matter what I do they 'stick' when the chassis rests. Chassis is a TT02B I started with the stock TT02B dampers, essentially the 54567 DT03 set. They built fine but if I left the chassis for an hour or so they would stick solid and need a very firm push to 'unlock' So I rebuilt them adding some green slime to the o-rings. They still stuck So I rebuilt them again, replacing the one-piece pistons with rods and pistons left over from a DF03 build (essentially the 50519 / 50520 sets). I used white TRF pistons on the fronts, and replaced the black o-rings with red throughout They still stuck So I ordered some new cylinders from Tamico (thinking maybe I had a duff set) and rebuilt them again. They still stick So, having started with the DT03 set, I have now replaced: rods pistons o-rings cyclinders They're basically the CVA equivalent of Trigger's Broom But they still stick I've built plenty of the super-minis on touring cars and they never stick, but generally tend to upgrade to aluminium dampers on buggy builds (DF03 dampers on the DF03 and Boomerang, hi-caps on the Super Astute) I've got a re:re Bigwig with yellow CVAs and they never stick either, and that can get left for months before I pick it up and run it again So, is this just a 'thing' with the CVA buggy dampers? Has anyone else experienced this, or managed so solve it? 1 Share this post Link to post Share on other sites
Saito2 6573 Posted July 17, 2022 I've seen the lower body cap, that holds in the o-rings, with their holes drill off center which created a bind between it and the main body. This was on an original CVA 1 equipped Dirt Trasher though. My only other thought is the o-rings are getting compressed too much when the lower cap is screwed down. You could try loosening the cap (but not enough to allow leakage) and re-try the experiment. You've tried different rods but are both rod surfaces smooth? I vaguely recall seeing both DF03 and fixed one- piece piston rods sometimes come in that dull un-polished blackish gray color (as opposed to the shiny polished silver look of most rods). If both sets you've tried are like that, they could be polished with some emery cloth. 1 Share this post Link to post Share on other sites
Rvl 2 16 Posted July 17, 2022 3 hours ago, Juhunio said: I'm struggling with a set of CVA dampers at the moment; no matter what I do they 'stick' when the chassis rests. Chassis is a TT02B I started with the stock TT02B dampers, essentially the 54567 DT03 set. They built fine but if I left the chassis for an hour or so they would stick solid and need a very firm push to 'unlock' So I rebuilt them adding some green slime to the o-rings. They still stuck So I rebuilt them again, replacing the one-piece pistons with rods and pistons left over from a DF03 build (essentially the 50519 / 50520 sets). I used white TRF pistons on the fronts, and replaced the black o-rings with red throughout They still stuck So I ordered some new cylinders from Tamico (thinking maybe I had a duff set) and rebuilt them again. They still stick So, having started with the DT03 set, I have now replaced: rods pistons o-rings cyclinders They're basically the CVA equivalent of Trigger's Broom But they still stick I've built plenty of the super-minis on touring cars and they never stick, but generally tend to upgrade to aluminium dampers on buggy builds (DF03 dampers on the DF03 and Boomerang, hi-caps on the Super Astute) I've got a re:re Bigwig with yellow CVAs and they never stick either, and that can get left for months before I pick it up and run it again So, is this just a 'thing' with the CVA buggy dampers? Has anyone else experienced this, or managed so solve it? Send me some photos and I will try to help rvanlane at gmail . Com or post photos here Share this post Link to post Share on other sites
GTodd 1306 Posted July 17, 2022 Here is some additional info. The rere Hicaps that come with the TF EVO include Big Bore springs! This alows the ability to tune the car with the big bore buggy spring set. Share this post Link to post Share on other sites