Kyosho Ultima RB6 & RB6.6 Car Thread
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#5026
#5028
www(dot)kyosho(dot)com/jpn/products/rc/parts_images/UMW702.jpg
www(dot)kyosho(dot)com/jpn/products/rc/parts_images/UMW703.jpg
These were on the kyosho website yesterday
www(dot)kyosho(dot)com/jpn/products/rc/parts_images/UMW703.jpg
These were on the kyosho website yesterday
#5034
1. A wider track technically raises your roll center (which increases roll resistance)as your contact patch is now farther away from the center of the car. Roll center by ELVO
2. Your lower shock mount is technically farther away from the car as well, and if your shock length hasn't changed, you have removed droop. (which reduces roll)
3. It's possible the wider lower shock mount position also makes the rear suspension stiffer... unless that's determined by the distance from the pivot rather than the middle of the car.... im not sure if it is.
Any way you cut it, all of theses will reduce traction in the rear, and increase steering. There is ONE scenario where raising your roll center and increasing roll resistance will increase traction instead of decreasing, and that is if you generate SO much traction and roll, that you actually go over the edge of your traction curve, and go into a skid (what happens with 1:1 cars). In that case, stiffer/wider/more roll resistance can actually aid in traction, because you are no longer skidding out. You need to understand how the traction curve of a rubber tire works to get your head around it.
Last edited by Cpt.America; 02-07-2013 at 11:36 AM.
#5035
Tech Master
iTrader: (66)
Not to be a smart ass but my car rotated better with the narrow blocks and less with the wider ones. Exact opposite of what u just explained. My suspension feels softer with the wider blocks. As far as roll resistance is considered, u got me there. Maybe my car is the odd ball but I had different results
#5036
Not to be a smart ass but my car rotated better with the narrow blocks and less with the wider ones. Exact opposite of what u just explained. My suspension feels softer with the wider blocks. As far as roll resistance is considered, u got me there. Maybe my car is the odd ball but I had different results
Sometimes other things are felt MUCH more. For example, lets say you ran the wide blocks in the morning when traction was high... Then lets say you took a couple hours away and changed your blocks to the narrows. In the mean time, traction on the track dropped for whatever reason... You put the car down with the new narrow hangers and your rear-end is now looser due to less traction, and you say to yourself "hey... more rotation with these narrow hangers"... it wasn't the hangers, it was the track.
Obviously this is just an example of what can happen, not necessarily what did. Could of been all kinds of things.
#5037
Tech Champion
iTrader: (73)
Not to be a smart ass but my car rotated better with the narrow blocks and less with the wider ones. Exact opposite of what u just explained. My suspension feels softer with the wider blocks. As far as roll resistance is considered, u got me there. Maybe my car is the odd ball but I had different results
Things also depend on the balance of you car, if the rear was already locked in, how a change feels will vary vs a car that was very free.
#5038
Don't think of it as "more or less traction", think of it as "more or less traction gain" This is because you develop more and more traction, the more the car rolls.
Picture car #1, a car that has it's suspension locked down so the arms can't move. If the car can't roll, the amount of traction the car has on either end of the car, will be the same at corner entrance, mid, and exit, because the car stays completely flat. You will have zero traction gain, throughout a corner.
Now, lets say you have car #2, a car with proper suspension, with a super low roll center. This car will roll a lot. The peak of it's roll will be dead smack mid corner. So picture the "curve" of your traction change. This car's curve will be tall and steep as it approaches mid corner, and then come back down again as it exits. The first car's curve would be about flat.
If you overlayed the two graphs on top of eachother, at the very entrance to the corner, the relative difference between the two is very close... and same with the very exit. The BIG difference between the two, will be in the middle.
So if you run a wider track, and therefor less roll (less traction gain)... you might say to yourself (or feel), "man this car has more rear traction at corner exit"... well, it doesn't have more traction at corner exit, it just has LESS traction mid corner than a car with a bigger curve, so you might perceive more exit traction because of how much traction it has mid corner.
Did that make any sense? I have a hard time understand what I wrote myself... I need to draw up some graphs.
What will really get you is when you start changing angles and lengths of your tie rodes, you change the shape of these traction curve graphs.
Picture car #1, a car that has it's suspension locked down so the arms can't move. If the car can't roll, the amount of traction the car has on either end of the car, will be the same at corner entrance, mid, and exit, because the car stays completely flat. You will have zero traction gain, throughout a corner.
Now, lets say you have car #2, a car with proper suspension, with a super low roll center. This car will roll a lot. The peak of it's roll will be dead smack mid corner. So picture the "curve" of your traction change. This car's curve will be tall and steep as it approaches mid corner, and then come back down again as it exits. The first car's curve would be about flat.
If you overlayed the two graphs on top of eachother, at the very entrance to the corner, the relative difference between the two is very close... and same with the very exit. The BIG difference between the two, will be in the middle.
So if you run a wider track, and therefor less roll (less traction gain)... you might say to yourself (or feel), "man this car has more rear traction at corner exit"... well, it doesn't have more traction at corner exit, it just has LESS traction mid corner than a car with a bigger curve, so you might perceive more exit traction because of how much traction it has mid corner.
Did that make any sense? I have a hard time understand what I wrote myself... I need to draw up some graphs.
What will really get you is when you start changing angles and lengths of your tie rodes, you change the shape of these traction curve graphs.