Simply put, you have steer tires and drive tires. weight bias will favor which ever one is heavier. High rear weight will promote rear traction and less steering, low rear weight will give more steering. From there its a balance depending on the driver.

Nick

My crapwagon is heavier than your crapwagon!

When I look at the SC10 RTR stock setup, it appears as though they had a setup with tons of steering, maybe something that pros could drive but the rest of us mortals would struggle with, and they simply softened the rear end up a ton as a quick fix to try to get some semblance of traction back there for the rest of us. For me, it still needed more traction in the back, but it bottomed out bad on relatively small jumps and just felt really unbalanced. Granted, the RTR tires are terrible for most tracks, too... Nothing a set of decent tires, the adjustable rear arm mounts (for cranking in some toe), balanced springs (the Swainish setup) and a little knowledge about roll centers and setup doesn't fix. Plus, as bds said above, wheel time makes a big difference, too, probably the biggest of all.

X-6 :
Front:
517g
Rear:
943.4


SCX-60:
Front
871.1
Rear
1377.3

SC10FT-
Battery forward 3oz weight under rear pad: Front-24.8oz Rear-42.2 (37F/63R)
Battery back 3oz under pad placed forward: Front-24.0oz Rear-42.3 (36F/64R)
Battery back no weight under pad forward: Front-22.1oz Rear-41.35oz (35F/65R)

As much as I'd like to, I cannot take credit for Paul Tracy's quote (he was speaking about IRL cars in 2004; which, compared to CART cars, were crapwagons). In any case, I submit:

http://www.crapwagon.com/forums/

I started racing in 1990. You could have a car back then that handled poorly and a world class driver could make up the difference. Now you're just slow. That doesn't mean the fast guys who like a chassis that is on the 'racy' side are doing it right.

A good friend of mine (a former ROAR national champion in pan cars) only races foam because waaaaay back when the XX was new, he was friends with Hodapp and all those guys, and he told me he never could get used to running a car as loose as they did on dirt. His fatal flaw as an all around driver is he just drove no matter how bad or good the car was. He's a wheel man, not a chassis development guy.

I am currently at Page 7 but this is one of the best threads I have had the pleasure of reading, thnaks Fred for taking the time to put these thoughts to screen

Sean

Waaaaay back when the XX was new? Holy cow, that's not way back. I started racing a Tamiya Fox before I got an RC10. It was the new ground breaking fast car that came out a year earlier. The 80's were exciting times in rc. If I could go back to then and do it all over again, I'd give up everything we have in rc today and do it in a second. The car to have was the RC10 and nearly everyone had one although there were a few Ultimas here and there. You could have 30 RC10's there and they were all different. You'd have a graphite chassis and wide front arms on one car, a graphite chassis with a wide front end but narrow front arms, a red Hot Trick chassis that used the stock aluminum nose, the stock tubs cut up and drilled with any number of lightening holes. You'd have 3 or 4 different styles of trailing arm rear suspensions. You'd have cars with belt drive or even chain drive gearbox conversions. Some cars ran all 1.6" wheels. Others ran all 2" wheels. Some like myself ran the 1.6's in the back and 2's in front. I could go on an on. You'd see a dozen different name brand motors. No one had the same setup and no one ran anyone's else's setup. You figured things out on your own. There was no copying some team drivers setup. RC today is downright boring and I personally consider the direction that off road has gone today to be a bad joke played on the hobby. It doesn't encourage learning or experimenting. When you have someone that does, you get ignorant people that criticize them saying it's a waste of time because manufacturers and pros don't do it that way. That's WHY you do it!

I was one of the first people at the track here with a JRX2. The week I saw it I got one. Multilink rear suspension, a 20 degree front kick, and a short wheelbase. Unfortunately I bought it because it was the new big deal. I only won 1 race with it. It was a B main dirt oval race. The only dirt oval race I'd ever done. I didn't know what I was doing back then but on my limited lawn mowing budget I couldn't afford to do too much anyways. I still have a JRX today. 2 actually and enough spares to build at least another. Still got an RC10 too. I could probably build 2 of them. Until a year ago my NEW car was a XX! My current race car I'm playing with is a mid motor XXX. We run on hard, sometimes loose clay. I'd rather race on the old loamy soft rough dirt tracks of the old days. Our cars ran about 20 mph and it was more fun than anything today. I miss those days.

Thanks for those. Nearly 65% on the rear wheels vs the 62-63% I've heard from many European mid motor people. It's not hard to see why the X6 is reported to have decent rear traction for a mid car.

I started with the Hornet (certainly not a race car by any stretch) but quickly progressed to a gold pan RC10. Eventually the gold pan changed to a ridiculously thin red Hot Trick chassis that was alarmingly flexible. At that point, I still had the stock aluminum nose but added the wide Andy's front arms soon after. Eventually the Hot Trick chassis was replaced with an absolute hot rod foam filled carbon fiber monster with an integrated nose kick in the front. At one point, I ran MIP rear trailing arms. Simple design but extremely prone to bending dog bones. Handled well in the rough but like crap on the smooth fast parts of the track. I remember wandering into the hobby shop and just looking at the wall of parts to see if there were any silver bullets I could stick on that car. That was a fun time, Fred. I was good back then too. Makes my bottom of the pack finishes now even more humbling.

I'm running a shorty lipo in both cars and with the X6 the lipo is running down the center. The only extra weight I have is in the X6 with a single 1/4 oz in front of the servo.

You've got that weight bias with weight added forward? That's really telling about those cars. Not in a bad way.

I've moved the placement of the esc and reciever several times now. When I ran a full lipo I had both of them sitting in the middle just in front of the battery. So with the shorty I thought I would run it down the center just to try something different but moved the esc and reciever back into the battery compartment on either side of the battery. That was just too much, because I had way to much rear traction and the car would not turn. I have moved them back closer to the center and I might move them forward a bit.

From my experience of moving the battery forward it I have made to observations-

1- it definitely makes a difference on the steering.

2- Adding 3 oz under the battery foam placed to the rear only compensated for the 'loss' of moving the battery forward. In other words the rear was the same on the scales but the front gained some.

Something I'm uncertain about is the loose off-power problem I'm fighting. It really became obvious after moving the battery forward. Tomorrow I'll hit the track with no weight and battery all the way to the rear. If time allows here at work I'm putting together about 2 oz of weight to place behind the battery that keeps the battery as close to the rear as possible.

Fred, it's nice to see there are still some people out there that like to analyze & try things on their own. People will ridicule you until they see you are onto something. Then they will attract to you like a bum on a free sandwich. Guess it's true people are a lot like sheep.

....now where did I put that 'kit setup sheet'?

That was my first car too, I started racing in 1990.

I too miss fluff tracks.

+ YouTube Video

Joe@South West Tour posted the 1992 IFMAR 12th scale worlds from Detroit a couple of days back. A user commented that the cars handled poorly and if they tried to run the worlds on a 'green' track like they did then, there would be a riot. Can you imagine a world class race on a track like Detroit today?

My standard car setup was very simple. Run the bottom of the shocks all the way out on the arms, the tops all the way in on the shock towers. We didn't have adjustments to the location of the outer camber links so the key was to run the inside end as far in as possible. On the RC10 that was only 1 spot. Everyone ran the same thing. Get the car as light as you can. Gear it so you can finish the race. Springs were whatever came with the car. Basically the only things that were ever changed were tires and shock oil. Different motors, batteries, and brushes were tried too. That's it. I'm pretty sure they handled like crap. Fortunately everyone else's cars did too!