My brother and I both started with a Hornet, too. What an ill handling mess that thing was, but we had a blast. But, it doesn't apply to this thread....it didn't have camber links.....

I'm thinking the Hornet might be one of the few examples where the best driver can't win with the worst car. I think I could beat Maifield with my SC10 if he were driving a Hornet. Maybe I shouldn't say that.....

I have my XXX-SCT set up with a spring combo not even close to any I've ever seen. Thing is, in preliminary testing with no shock oil - the truck drove much more intuitively and had absolutely no tendency to become "upset" or "unstable" when "pushed" as it does with any of the setup sheets or advice I've seen/tried from any other source. The best part is that I am actually learning what I'm doing as I make changes!

In related news, I blew out a rear hub bearing and will not resume testing until Wednesday. I've worked diligently on getting thing thing set up since January and could previously only get it to 80% of what I felt was it's true potential. Even when I had it set up well enough that other driver's commented that it "looked good" on the track, it was a beast to drive. I am stoked!

If you come to AZ, we may be able to arrange it.

Official event name: "The Hornet Handicap"

Now I have proof that this method works. I won my first main since starting back in the hobby in January! Being able to read the track and make the proper tire changes is key, as our track changes quite a bit during the course of a night, but if you don't have the shocks and geometry set up, the tires aren't going to work very well anyway. Again, many thanks!

I've used this guide a couple of times and while I find it to be quite good, I found that I had to, or rather prefered to set the geometry/shock positions before sorting out the spring balance.

When doing it the way that is suggested, moving the shocks to help with balance, I found that the shock positions I would end up with was worse than setting the shocks then doing the springs.
I would end up with the shocks in positions that just did not suit anything.

I know my buggy will not steer on our track with the tyres I have unless the rear shocks are on the inside hole on the A-Arm.
So I just set the shocks to how I want/like them, then try to balance with springs as best I can (the shock tower holes I find are better for fine tuning, they dont make anywhere near as much difference as the A-Arm positions).

Just what I've found anyway.

Fred, I'm in the process of tuning my 2wd stadium truck with your balanced method and need a little help.
I got the front and rear springs balanced and found I had to go quite a bit softer on the front, from 3.2 to 2.3 spring rate. On the rear, I went up from 1.8 to 2. The truck handled bumps great, but had way too much steering going in and coming out of the corners. I set the front RC as high as the settings would allow, and I also put the lowest grip front tire that I had, basically bald tires. I still had too much steering. I increased the front oil weight quite a bit to try and stop the front end from rolling so much. I ended up with 60W front, and 22.5W rear. The truck still has too much steering. The rear RC is already as low as I can go.
What should I do next?

The front roll center needs to be lower and the rear higher. You've got it backwards.

I think he meant the link on the tower is as low as it will go.

The front camber link on the inside needs to be shimmed higher under ball stud to get lower roll center.

Inside rear camber link needs shims removed under ball stud to achieve higher roll center.

Is what he means. pls correct me if I'm wrong fredswain...

I thought that a high roll center increase roll stiffness and reduces grip. And a low roll center decreases roll stiffness and increase grip.
If I lower the front roll center, wouldn't the front roll even more in the corners and give me more steering?

Oops. You aren't backwards. I read it backwards. My bad.

You've hit upon a situation that brings us to the next step in tuning and this is going to mess some people up. First off you could try sway bars instead of camber link adjustments. The more and more I learn about suspensions (and I never plan to stop learning) the more I am rethinking a few things. Roll centers being one of them. I think it's time the term goes the way of the dodo. It's irrelevant as the vehicle doesn't roll about a theoretical axis location in space but rather moves in reaction to the lateral forces during cornering. Confused yet? Here's what is relevant. Stop thinking in terms of roll centers. It's relevant with the car sitting still but not when both sides of the suspension are moving in dependently of each other as they nearly always are. Think in terms of roll resistance. Now we can go on.

As we know when we change camber link locations, we also get different amounts of camber gain. With the upper link exactly parallel to the arms and the exact same length as the arms, the wheels move straight up and down and we get no camber gain at all. This is a large contributing factor why the car has a tendency to slide more controllably at the edge of adhesion. The tire has rolled over towards the outside and we are no longer applying force to the center of the tread. We are pulling it along like a broom against the track. Both tires are at the same attitude and therefore traction is more evenly distributed between them.

When we get some camber gain involved, we are keeping more of the face of the tread against the track which means the tire will use ore tread. Try pushing a standard broom (not a large push broom) with the bristles pointing towards the ground. It digs in. Incidentally the broom analogy is a common one for describing the effect of roll centers but I believe it to be more relevant in regards to tire attitude in a lean. Inducing a little bit of static negative camber accomplishes the same thing to a lesser extent. It's more for fine tuning. So what does this all mean in terms of real world tuning? This is where I am evolving.

I feel that the maximum amount of tire touching the ground at all times results in the most traction. Logical right? I prefer to run little to no negative camber. Maybe a degree or 2 at max. Start with the camber links as close to parallel and length to the arms as possible. You will have very little camber gain at this point. The vehicle will be the most forgiving in this manner but it may not necessarily turn as well as we'd like. Drive around your track. Preferably with a set of tires you don't mind wearing down. Watch the tread wear. If the wear favors the outside edge of the tires, adjust your camber link length shorter a notch. If you get more wear on the inside of the tires than the outside or center, you've got too much camber gain. You get the idea. Learn to read your tires. Do this front and rear until your tread wear pattern is even across the face of the tire. I'm not going to get into foams since this is going to be up to you to play with.

Now what if we are using all of our tire tread with link adjustments but we still aren't getting the cornering that we'd like? This is where I'd bring a sway bar into the mix. If you oversteer, add a bar up front. If you understeer, add one at the rear. Adjust sizes accordingly. A slower track (or class) may be able to run a higher amount of roll resistance than a faster track or class so don't be afraid to adjust according to what motor you run in addition to what track you run at.

Now there is a scenarios to touch on here and this gets into modern tuning techniques that we didn't believe in, in the old days. What if you run sway bars but the vehicle doesn't take the bumps as well anymore? Move some weight around. How? This probably means you are going to add weight. I hate adding weight. It's backwards yet people do it and get good results. Just don't arbitrarily add weigh for the sake of making it heavier. That's the wrong way to do it. The important thing is front to rear weight distribution.

I'm going to start referring to 2wd but it applies across the board. Many people say that a mid motor car corners better than a rear motor car. Well...yes and no. There are certainly advantages to a mid motor scenario such as all of the weight being inside the wheelbase and closer to the polar moment of inertia. However that's now why they corner better or not. It's just why they are more forgiving.

More weight rearwards is EASIER to turn. Sound backwards from what you've always heard? jha07 has a setup that is proving this very well. He has too much steering no matter what he does. How can he fix this? Add weight forwards and rebalance. Now you are probably really confused since adding weight forwards has always been recommended to help turn better. If more weight is added forwards changing the weight balance, the springs will have to be rebalanced again so that's a downside.

A high amount of rear weight means the center of gravity is shifted quite far rearwards. This means the front wheels are far away from the polar moment. Think of this distance as leverage. Now don't get too carried away with this as a car 3 feet long won't turn very well. Again, don't believe me? Look up the Nissan Deltawing race car that will be running in the 24 Hours of LeMans in a few weeks. It has a weight distribution of 72.5% rear with a very narrow 24" wide front end. That car turns quite well. Incidentally the front being narrow and also lacking any roll resistance means that all the wheels stay on the ground cornering. Ever had a scenario where the back end of the vehicle comes around in hard braking while the inside front wheels lifts during on power acceleration? I'm not suggesting you narrow the front end since we need a wide stance for off road stability but the point is clear. The roll resistance needs to be greatest where the weight is located.

Now lets say we have a car that has tons of weight up front with little in the rear. The opposite is going to be true of the rear biased car. It will understeer. It will feel stable but understeer usually does. Play with your front to rear weight distribution. If you've got 70% of your weight on the rear wheels and it oversteers like crazy, move some weight forwards and rebalance/readjust. Also, the more weight is shifted rearwards, the less critical front tire selection becomes. You'll find that you may have a setup that corners well with high rear bias but it may not handle bumps as well as it could. Then again you could just be on a very smooth track too.

I fear that I'm getting too complex at one time and some things may sound contradictory which is a danger with trying to discuss too many things at once. Anyways, think differently.

My tuning took my SCT from severe push to oversteer - but at least the rear doesn't pendulum! I dealt with the touchy steering via exponential on the radio. Not sure if this is ideal, but my laps times are much better than they were when I had to brake to turn at all!

I use exponential. It's another tuning aid. Use it! You can actually have a more aggressive car that is controllable if you take advantage of all the electronic features.


jha07: I forgot to ask, how is your diff adjusted? Loose? Tight?

My diff is fairly tight by feel. But it's only as tight as I need to keep it from slipping.
From day one, I've found this truck to have too much steering and would have liked to put a front sway bar on. Unfortunitly, they don't make one. Initally, I increased the front spring rate to calm the steering down. Of course this sucked over bumps and jumps. Later, I figured out the a lower RC through camber links in the rear helped, purely through trial and error, so I could put the stock front spring back on. Of course the stock front spring is still way out of balance.
I never tried raising the front RC until recently, because I didn't know enough about camber links. To be honest, I really didn't notice much of a change in handling.
I think I understand what you mean as for as adding weight to the front. With more weight, I can run a heavier front and softer rear spring and still be balanced. My only concern is, right now, my car had 65% rear weight. If I add more weight to the front, even if I fix the steering problems, I'm going to have reduced forward traction down the straights. As it is now, I feel like the truck needs more forward tractions. Many times, I've lost control of the rear while I'm already half way down the straightaway.