this is good stuff there guys.

Shocks positions will also need to be taken into consideration when adjusting springs shock oil pistons etc on test days. IMO this is crucial as well.

Unless you have a dual spring setup or progressive wound springs, the actual spring rate of your spring stays constant. Preload has nothing to do with spring rates, but directly affects ride height. Ride height plays a significant role in how your vehicle handles as well, including how it jumps- or how poorly it jumps.

To Fred- I have really enjoyed your explanantions and approaches to vehicle tuning. I'll be reading as long as you keep writing

I fully agree. I have to rebuild my 2WD and should have some time to give this a go this week.

Thanks Fred! I've been looking for a systematic way to approach suspension tuning. Looks like I've found it.. Keep 'em coming...

Now take in effect when you change shock positions like on the tower or arms etc should you change springs oil etc.

For example if you lay your shock down on the tower making them softer should you make the spring stiffer and oil a bit heavier.

Good stuff, subscribed.

While I do my balancing I think I will test this collar question by simply pressing down on one side of the suspension and then releasing it to see the recoil with the collars all the way put. Then I will tighten them down significantly and perform the same test. Each test with just springs and without shock oil. If the spring rate remains the same (which I suspect it may) I'll be convinced

How does this dictate over wieght transfer? like if you need more forward bite? I reallyt like this thread and it makes sence just curious on this.

As you tighten down the collars, you'll also be changing the ride height. As mentioned earlier, adjusting the collar is solely to change ride height, and not spring rate.

There are several other things you can do to increase forward traction. I don't know your setup, but you can add toe, anti-squat, weight, select the right tire, soften the suspension, shorten the wheelbase, etc. etc.

I fully expect people to be skeptical of this method, especially since no one has ever taught it in the r/c world as far as I know. Even if you are a skeptic, you have nothing to lose by trying this. If you don't like it, you can go back to your way of doing things. I'm not selling anything and have nothing to gain by this. The worst that can happen is that I look like an idiot and so does everyone tuning real race cars. I'm not to concerned about looking bad though!

This is a technique that must be done in a certain order. Don't second guess things and don't try to do things out of order. One step at a time. That's how you know what works and how.

Shock collars will have a slight effect on spring rate as you are tightening the springs as you move the collars down or up with the rate being affected more and more with the springs getting tightened. What happens if you get the collars all they way down and get a decent spring rate but then your ride height is far too high? What then? Do you then use shock travel limiters to hold it back down which would ultimately hurt you on jumps? What happens if you have them as loose as possible and it's nice but your ride height is now on the ground? Do you then find a way to mount the top of the shock lower and hence limit suspension travel? Forget what you know about the shock collars and their effect on the springs. Use them only to determine your ride height and rely on the springs themselves to determine the rate. This way you don't need to use other bandaid solutions to fix other problems. Too many setups and bandaid on top of bandaid.

We've all been taught that shock mounting location is important and that different mounting locations have different effects on handling. They do. Don't think they don't. I'm not saying to throw that knowledge out the door. However you must maintain balance when utilizing any location.

If you only have 1 full set of springs, you may only find one mounting location for your shocks that achieves balances, assuming you find that balance at all. Not every spring combo can result in balance regardless of location. If you have only 1 set of springs, you must obtain balance first and foremost.

If you have a full set of spring options available to you, you may have several combinations that end up in balance. You just have to figure out what these mounting locations would be for each combo and then determine which one works best for you. If you want to run your shocks all the way out on the arms and all the way in on the shock towers, that's fine. Find a spring combination that achieves frequency balance with this location. If you can't find a combo that balances, don't use these locations. Hopefully that clears that up a bit.

Shock oil is not to be used as a compensation for spring rate deficiency. They are 2 independent things that should be allowed to do their jobs as intended. If you move a shock over but leave the same springs (you probably shouldn't though), you don't just change your shock oil to compensate in any way.

In the old days we'd run the upper links as long as we could and then leave them alone. We usually only had 1 or 2 spring options, and a couple of different shock piston options. We'd run the shocks all the way out on the bottom and all the way in on top. Why? It's what others were doing and said to do. They were typically faster so they must be right. Then from there we'd constantly adjust the shock collars and shock oil weights. It seemed like no matter what you did, it improved one thing but hurt another. That was actually true though as it was bandaid tuning. Then again I was a kid back then and didn't know any better.

Ok. I have conducted my testing on the shock collars regarding the spring rate question and here is what I found.

I began my test with no fluid in my shocks with all collars threaded 100% out. After a few experimental drops I found that at a height of 8 inches with a perfectly balanced drop it barely made the chassis bottom out. I then conducted another test by allowing the car to sit flat on an even hard surface and I pressed down on the entire car to observe it's recoil. I then did each end individually with the front and the rear again while observing recoil.

After observing all recoil with collars 100% out and noting my results I then, still with no shock fluid, tightened down the shock collars on all shocks approximately 12 threads and conducted the same tests.

From a height of 8 inches (same as before with no collar adjustment) the chassis did not bottom out. It wasn't until 13 inches did the chassis bottom out on the same manner as with the 8 inch drop with no collar adjustment. I then pressed on the suspension in all the same manner I did with the other test and with each (entire car, front, and rear) I not only felt more resistance, I observed an increased spring rate.

Per all of my tests and observations I lust conclude that shock collars do in fact put the suspension under increased load creating a more fierce recoil. It did in fact change my ride height and with all said and done with a balanced adjustment and a spring recoil I'm happy with in front and back I am 7 threads down on the front and 13 threads down on the back. My car has an even bounce to it through and through. Thank u Fred for some great advice to begin calibration of suspension as such, but it's just too apparent to me these collars play a large role in set up in the off road 1/8 scale class at least.

I'm learning so much on this thread so don't take this as debate or doubt. I'd very much like to continue our discussion in oil weights, camber, etc... I appreciate the explanations thus far. Just one man's opinion in a specific class regarding the collars and their role thats all.

They did change ride height from my starting point of 25mm to 42mm. So yet do play a significant role with that as well. I just don't think the collars role stops there.

Btw fred we were posting at the same time and I see u addressed the collars ad their role. I agree with ur statements and appreciate them. I do agree if u use the collars as ur only means of adjusting the frequency of ur springs u will have a height issue.

What I didn't go on to say is I did in fact do as u said. I moved my mounting locations I think like 10 times front and rear with my collars in the desired locations. Interesting combinations as issue it would be. In outer hole on the suspension arms in the front, inner in the back. I'm 4 holes from the bottom on the tower in the front and 3 in the rear. My toe needed some adjustment as this was thrown slightly due to the new set up. I put it to zero degrees as a starting point.

I dropped the car several times and pressed on it and I have great balance. The spring frequency front to rear is perfectly even and the car seems to be very stable. Yes... I did collar adjustment but as u said.. Put it to what u want and forget it. I have done so and have good balance. I'm ready for tr next step Fred!

Great Information guys, keep it coming.

it is interesting terminology applied to rc cars for sure. Basically he is saying just find the sweet spot between the spring rate and shock dampening. Kind of match your dampening up with your spring rate if it is possible. It can be done with testing etc.