I did some testing on my big backyard track which is loamy with high traction. I could really tell a difference in playing with the inside camber links front and rear. I tried no washer, 1 washer and 2 washer setups and I could really see how each affected handling, especially in the high speed sweeper. I ended up with 2 washers in the rear and one in the front. The truck is really dialed and I couldn't be happier. I have learned so much reading this thread.

You Tube a lap at Danny's to see a lap at my track. It's a high quality video with slo mo shots. You'll really see the suspensions at work. I tried posting a link here but I don't have that priveledge yet.

I've been reading along and found spring balance for my DEX410v3, but have some questions:

Rollbar: If I use a rear anti-roll bar, do I spring-balance with it attached, or not?

Pistons: If the total piston hole area is the same, what's the difference with 6-hole or 4-hole pistons?

How would I tell if I need shock limiters or not?

Rollbar: if Its installed properly and moves freely it has no effect on spring balancing ftont to rear. Rollbar works left to right.

Pistons: the more holes will cause more shearing of fluid. More pack.

Shock limiters: less aid better rough track handling (more tire to ground contact), more aid in limiting traction rolls.

Spring balance with anything in the car that will be there when it races. In theory the sway bar shouldn't affect the spring rate but it probably will slightly. If nothing else it is weight that will need to be moved by the springs.

Limiters are used in 1/10th classes for adjusting droop. Do some google searches on droop to learn all about it. Basically it is controlling the amount of weight transfer. It affects weight transfer from front to rear and side to side. For example, if you are traction rolling because the rear end is rolling over a bit too far and jacking the car over, you could reduce the droop in the rear to try to keep it from rolling quite as far. Or if you needed a bit more exit steering you could reduce the amount of droop in the front to limit the weight transfer to the rear under acceleration.

If I only add ballstud washers under rear hub and not under inner ballstud what will happen with the car?

Higher roll center, more camber gain, at least the way I read it.

If the washers are under the inner ballstud and not the hub, then lower roll center and less camber gain.

Hi All,

I have a question about increasing pack on the associated big bores. I need a little more pack front and rear, did the math in the three hole (1.3mm) verses standard two hole (1.6mm). hole area for the two hole 1.6 is 5.024mm for the 1.3 three hole is 6.123mm, that's a significant difference in hole area. question, I am going to have to go up in oil weight to retain the damping I have now (its pretty close to spot on for bumps) will that increase the pack too much? or am I way off on my calculations and assumptions about hole area and oil flow?

Steve

Hi Steve,

I've been trying to do something similar, in terms of quantifying the pack and oil required for dampening etc.

I've read in a few places that the circumference of the hole has an influence on the pack characteristics, as well as the total hole area, so I made a few calculations and used them to produce a pretty good balance so far after testing.

First I take a ratio of the front to rear shaft length at full extension when mounted to get a ratio of shaft speed when going from full extension to full compression as this difference in speed affects the difference in pack tendency:

Rear Extended Length/ Front Extended Length - for my 22 2.0 I've got 1.26

I then take the ratio of the piston hole area (pi x squared radius) and the piston circumference (2 pi x radius) front to rear and then average them as they both have an influence on the pack of the shock:

Total Hole Area Rear / Total Hole Area Front - my set-up is 1.33
Total Hole Circumference Rear / Total Hole Circumference Front - my set-up is 1.15

Then the average of this is 1.24 - which is as close as I could get without having to drill the holes myself.

This is with 2 hole 1.3mm front and 2 hole 1.5mm rear.

To then set the oils in balance, primarily for slow speed dampening, I use the following as it is mainly the whole area size and oil thickness that affects slow speed dampening:

Front Shock Oil in cSt x Total Hole Area Front to Rear Ratio - for me it is Front 243cst x 1.33 = 324cst Required at rear.

When going from one spring to another for handling (but still in balance - so if going up all round for example), I use the following to try and keep everything in balance (so going up in springs needs an increase in oil thickness to keep consistent dampening feel):

Dampening Co-efficient Front = Front Shock Oil in cSt / Current Front Wheel Rate

Please note - This is an arbitrary unitless number used for comparison and calculation purposes e.g. as my oil cSt goes up (so gets thicker), my Dampening Co-efficient goes up (heavier dampening) if I was keeping the same wheel rate, but it would stay the same (so same dampening feel) if my wheel rate goes up too due to using a stiffer spring.

I then calculate the required increase in cSt for the new settings:

New Oil Thickness cSt Required = Dampening Co-efficient x New Front Wheel Rate.

I then use the previous above calculation for working out the new rear required oil cSt to achieve a new balance.


This is a long post, I know, but is put together off other information from previous posts on this thread and has worked out nicely during testing and when I changed from Schumacher to TLR.

It doesn't provide a magic bullet for set-up but provides me with a way of setting a neutral, balanced, set-up as a start point or to try and keep as many things consistent as possible when making changes.

I'm not sure if anyone is still feeding this article but I finally stumbled on it and would like to make sure I'm not missing something.

I have a 2wd slash that I'm working on for my son. What I see when I drop it from 4" with springs only (not oil) is, the front does not oscillate, it goes down once and comes up and stops. The rear likes to smack the bench, come up, and drop back down and stop.

If its hitting the bench do I need a stronger spring? Should the front end move more than it is?

When I push down the front and rear ends and let go, they come up at relatively the same speed. I have tried several springs and see little change other than how far they pop up from being held down. I hope I'm not missing something here but I would love to be corrected if I am.

Thanks for this thread, I have been reading it ALOT!!!

Red,

I don't remember page numbers, but somewhere Fred explains what you are seeing with one end slapping and the other end not slapping. Basically that is a difference in the magnitude of the response. You don't care about that (not right now anyway). All you want to know is if the front and back move up and down at the same frequency. If the front is rebounding, the rear should not still be compressing. And when the chassis slaps, think of that as interference. Your bench top is stopping the chassis before the springs have a chance to, and it invalidates the test results. Do your drop test from a smaller height.

I think you will find that you will have more success by pressing down on the cg with one finger and releasing. And only watch from the moment you release to the moment the shocks hit their maximum up-travel. this is how I do it, and I also set up a camera to record and play back in slow motion.

The difference you see will be slight and hard to catch by eye alone (possible, but maybe not the first time you do this method). Keep at it and good luck!

Thanks for the reply Nick. I have a basic understanding but finding springs seems to be more challanging than first expected. I am running Proline shocks and I am experimenting with traxxas springs because that is what I have the most of laying around. Not sure if I should run the proline shocks or the stock ultra shocks - I just want a springs that I can fit on a shock and be able to tune. If that requires me going back to stock plastic shocks, so be it.

I remember Fred talking about a video back in the first few posts...I sure wish he would find that time to post one of this Frequency tuning process.....sigh - what a pain in the keister! LOL

Use video to check the rate of rise of your chassis. That's what I have been doing. It makes it a little less error prone and subjective.

Anyone got recent thoughts on this with the Tekno SCT410?

saw this posted by John Wallace:

Right now I use the 6x1.5 custom made kyosho pistons all around, 35W front and 30W rear.

Looking at trying black springs up front (don't have grays) or an equivalent gray.

Green rears feels right around the track. Front just makes me wonder if its too stiff since using 3.8lb pink equivalents.

Alrighty, I was working on my Durango DEST210 stadium truck last night and WOW! You can really tell when you do NOT have balance! The front wheels popped up and snapped the front wheels off the table...even witht he battery moved just behind the servo!!!

So, I feel much better knowing my other car is VERY CLOSE if not on the money. I have a set of springs coming in the mail - YAY! This is starting to become enjoyable but dont tell my wife, she may stop me from doing it any longer.....

I smile when I hear that people that take the time to try this actually get good results. It's refreshing to see compared to all the people that think it's stupid to try since "the pros" don't do it this way. Wait until everyone figures out that the more front end kick you have, the longer the front arms should be than the rears in order to maintain equivalent roll centers front to rear!