Originally Posted by CarKing

Has anyone gotten any testing doen with the new 2.5mm chassis on asphalt? Any results or feedback you care to share?

Originally Posted by Adam?

Also, the ball connectors on my steering linkage... the ones with 5mm of spacers underneath? Yeah, those are stupidly easy to bend, aluminum, or setscrew method. Is there some trick (aside from not hitting things) to making them last longer? They seem to do better with only 3mm of spacers, but that's a pretty significant ackerman change, isn't it?

Originally Posted by Besercoe

I cut the head off a long 3mm screw and use it like a long set screw, use a shock top style ball stud.
Just note the the new ball is 1mm taller than the std stud, so you will need 1mm less spacing.
This method also allows you to go even more ackerman, which makes the car feel much better for me on low grip tracks.

Originally Posted by CraigM

how did you screw it in without a head on it another option is to use a long 3mm set screw (nitro cars have them, check parts from mugen/kyosho) and a hex headed pillow ball

Originally Posted by Besercoe

Just turn it into the alloy part with your fingers, and put your finger on the back of it in order to hold the threaded part still while you put the pillow ball in, once its finger tight, just nip it up with the 5.5mm driver.

I would prefer to get some long set screws but i have not found any, tobee craft do make long ones, RCModel have them, but my last order for parts was from RCMarket. Market only had short ones.

Originally Posted by racetech.com.au

When Would You Use Ackerman (or Anti-Ackerman)?

* When you set the negative camber, based on the tyre temperature readings for instance, you are maximising outside tyre grip, at the expense of inside tyre grip. Toe out helps to compensate for negative camber on the inside tyre. This indicates pro-Ackerman might be usefull for cars carrying a lot of negative camber.
* In using Ackerman steering we hope to be able to influence the slip angle on the inside tyre to our advantage. There will be a range of slip angles where the inside tyre will be producing near maximum grip (Figure 3). So we have a degree of flexibility in how much Ackerman we use.
* To rotate the car on corner entry we are talking about creating increasing drag at the inside tyre. As the cornering force builds the inside tyre must at some point reach it's optimum lateral grip. We then use Ackerman to toe the tyre out further - say increase the slip angle a couple of degrees. The tyre grip doesn't change that much but the longitudinal component of tyre grip, the tyre drag, does increase in line with the increased slip angle. For this to work we would need to know that we have sufficient steering angle to generate the Ackerman needed.
* If in the process above, we started to loose outside tyre grip, and the driver wound on some more lock, we would have increased drag at the outside tyre. We would then loose the effect. The oversteer torque we were looking for would be overcome by the larger understeer torque.
* The above indicates that pro-Ackerman would probably not work with low powered cars in fast corners. It might also be a problem generally with heavy cars with spool or locker diffs that might want to push a bit, such as V8 Supercars.
* With pro-Ackerman, the higher slip angle on the inside tyre will put more heat into the tyre. This will help bring the tyre up to temperature, but could overheat the tyre on a longer run.
* If our race car is faster with toe in, we will use anti-Ackerman. This implies a tyre curve where the lightly loaded inside tyre has maximum grip at a lesser slip angle (Figure 6a)
* Sprint cars and similar speedway, dirt short circuits, can make a lot of use of varying degrees of pro-Ackerman. With dirt tyres we expect very large slip angles. Nascars and similar will use anti-Ackerman (Figure 6a).
* With low profile tyres the slip angles will be a lot less. The tyre drag will be less. The slip angle on the inside tyre will have a smaller drag component (Figure 8). So it may be
* more difficult to use pro-Ackerman to create the oversteer torque. The toe out from the slip angles will be less. The slip angle variation from outside to inside tyre will be a smaller number, requiring different Ackerman to achieve what we want. We will probably use initial toe out to help turn in. The idea is to get the inside tyre working as discussed earlier. Other settings you would use to help initial turn in are stiffer front shocks, and higher front roll centre height. By delaying the roll we help to keep the weight on the inside, to again keep the inside tyre working.
* We make the assumption that the outside wheel will always have the ideal trajectory, with all the toe out being seen at the inside wheel. This may not always be the case. For instance, if the car has a lot of caster and/or caster trail this might have the effect of splitting some of the toe to the outside wheel. If the outside wheel does take on some of the toe out, this will decrease slip angle and the outside wheel will loose grip.

Originally Posted by CraigM

mushroom have them too, they have take off 3x10s if the 3x12s are too long. I think I've got a bunch anyway, will stick some in my kit for you if I do.

How many spacers were you running anyway? I tried 6mm as there was an MS setup that used that but the steering rods bump the suspension block, maybe 5.5 might be alright tho

Originally Posted by Besercoe

Kool Thanks

I had the original shock ball, and i think 2, 3mm spacers. It brings the ball cups to within around 1mm of the toe block. I found that it gave the car a lot more mid to exit steering that it was really lacking before.
This is with the ackerman on the rear holes in the upright of course.