52LikesTeam Losi JRXS Type-R
11-23-2008, 05:18 AM
#8522
Tech Addict
) I was curious if anyone had something more specific... 
11-23-2008, 07:34 PM
#8524
Diff Hi / Low??
I recently copied Mike's Rubber setup and got some laps in this Saturday.
This is the best one-way setup I've ever tried. On our low bite track, one-ways have always been super twitchy in the past.. So.. Bravo!!!
Something that I noticed I missed when copying setup is the High rear Diff (mine is set low). I've been searching to find what effects front/rear diff height have and haven't found anything. What effect does this have?
On power steering is plenty.
Corner entry steering is OK.
Mid-corner steering (or flowing corners, where not braking or accel) needs some more steering.
Any suggested tweaks from here? Thinking about going from 17.5 springs all around to 15's?
This is the best one-way setup I've ever tried. On our low bite track, one-ways have always been super twitchy in the past.. So.. Bravo!!!
Something that I noticed I missed when copying setup is the High rear Diff (mine is set low). I've been searching to find what effects front/rear diff height have and haven't found anything. What effect does this have?
On power steering is plenty.
Corner entry steering is OK.
Mid-corner steering (or flowing corners, where not braking or accel) needs some more steering.
Any suggested tweaks from here? Thinking about going from 17.5 springs all around to 15's?
11-23-2008, 08:03 PM
#8525
If your car is pushy, raise the rear diff and it will free it up, and let it rotate more.
Glad you like the setup
Glad you like the setup
11-24-2008, 11:27 AM
#8526
Tech Initiate
Wow!! This car responds to chances different than my other Tamiya and Xray cars.
For example, roll center changes. Dont know why, but the type R gets more steering when you use high roll centers, unlike the other cars, which usually gain more grip/traction when you use low roll centers. Why is that?
For example, roll center changes. Dont know why, but the type R gets more steering when you use high roll centers, unlike the other cars, which usually gain more grip/traction when you use low roll centers. Why is that?
11-24-2008, 12:11 PM
#8527
Wow!! This car responds to chances different than my other Tamiya and Xray cars.
For example, roll center changes. Dont know why, but the type R gets more steering when you use high roll centers, unlike the other cars, which usually gain more grip/traction when you use low roll centers. Why is that?
For example, roll center changes. Dont know why, but the type R gets more steering when you use high roll centers, unlike the other cars, which usually gain more grip/traction when you use low roll centers. Why is that?
11-24-2008, 01:43 PM
#8528
Tech Initiate
"Q: What about at the suspension mounts?
[Todd Hodge] The suspension mounts offer a lot more in the roll center adjustability. By running a lower roll center, pins closer to the chassis, you will gain more roll in your chassis, which results in less use of the tire. By running a higher roll center, pins higher, you have a car that now drives flatter and places more of a load on the tire for traction. Generally speaking, a lower roll center will have less traction where a higher roll center has more traction. You can easily see this with foam tires, a place where we never use high roll center since it will make the car traction roll due to the increased traction capabilities of the higher roll centers..."
This is defenitely different from other cars. Because my other cars it was the opposite. Usually when you want more traction you use low roll center, and in high traction situation you use high roll center??
But when i ran my Type R on med traction asphalt it seemed like the using high roll center in front you get much better front end bite and traction, but then using front low roll center and rear low roll center it does have a much traction or steering up front.
Also, using front diff in the low position increase front steering?
Last edited by Adis; 11-24-2008 at 03:12 PM.
11-24-2008, 03:13 PM
#8529
Tech Initiate
Also, by using the #2 hole on the spindle, will I gain more steering, quicker steering reaction, or less steering?
What about the outer hole on the servo saver arm? most people use the inner hole on the servo saver arm, and i wonder what the outer hole will do? Quicker steering reaction?
What about the outer hole on the servo saver arm? most people use the inner hole on the servo saver arm, and i wonder what the outer hole will do? Quicker steering reaction?
11-24-2008, 03:29 PM
#8530
Tech Initiate
quick ? how do I gear my 17.5 losi brushless for foam tires on a track thats 80x40.
11-24-2008, 04:51 PM
#8531
Hey, I found this on Losi site...it's an article from todd hodge answering questions on the suspension and roll center: http://losi.com/Articles/Article.aspx?ArticleID=1562
"Q: What about at the suspension mounts?
[Todd Hodge] The suspension mounts offer a lot more in the roll center adjustability. By running a lower roll center, pins closer to the chassis, you will gain more roll in your chassis, which results in less use of the tire. By running a higher roll center, pins higher, you have a car that now drives flatter and places more of a load on the tire for traction. Generally speaking, a lower roll center will have less traction where a higher roll center has more traction. You can easily see this with foam tires, a place where we never use high roll center since it will make the car traction roll due to the increased traction capabilities of the higher roll centers..."
This is defenitely different from other cars. Because my other cars it was the opposite. Usually when you want more traction you use low roll center, and in high traction situation you use high roll center??
But when i ran my Type R on med traction asphalt it seemed like the using high roll center in front you get much better front end bite and traction, but then using front low roll center and rear low roll center it does have a much traction or steering up front.
Also, using front diff in the low position increase front steering?
"Q: What about at the suspension mounts?
[Todd Hodge] The suspension mounts offer a lot more in the roll center adjustability. By running a lower roll center, pins closer to the chassis, you will gain more roll in your chassis, which results in less use of the tire. By running a higher roll center, pins higher, you have a car that now drives flatter and places more of a load on the tire for traction. Generally speaking, a lower roll center will have less traction where a higher roll center has more traction. You can easily see this with foam tires, a place where we never use high roll center since it will make the car traction roll due to the increased traction capabilities of the higher roll centers..."
This is defenitely different from other cars. Because my other cars it was the opposite. Usually when you want more traction you use low roll center, and in high traction situation you use high roll center??
But when i ran my Type R on med traction asphalt it seemed like the using high roll center in front you get much better front end bite and traction, but then using front low roll center and rear low roll center it does have a much traction or steering up front.
Also, using front diff in the low position increase front steering?
I would have to agree that raising the roll centers on the hinge pins will free up the car. My rubber car I always start high front low rear and my foam I start low low. Than adjust up from there. With the Rubber tire car it is mostly about rotation. Going up on the rear til I like the amount of ratation or freeness in the middle of the corner. On my foam car it was more of raising equally til I was happy wiht the way the car carved the corner. The only other thing that I changed on my foam car was rear toe. I do feel like as I have raised the rear roll centers that it has always given a better freeness to the car, and a better rotation.
Anybody else have an opinion?
RedRocket
11-24-2008, 05:43 PM
#8532
Tech Initiate
Hmmmm....
I would have to agree that raising the roll centers on the hinge pins will free up the car. My rubber car I always start high front low rear and my foam I start low low. Than adjust up from there. With the Rubber tire car it is mostly about rotation. Going up on the rear til I like the amount of ratation or freeness in the middle of the corner. On my foam car it was more of raising equally til I was happy wiht the way the car carved the corner. The only other thing that I changed on my foam car was rear toe. I do feel like as I have raised the rear roll centers that it has always given a better freeness to the car, and a better rotation.
Anybody else have an opinion?
RedRocket
I would have to agree that raising the roll centers on the hinge pins will free up the car. My rubber car I always start high front low rear and my foam I start low low. Than adjust up from there. With the Rubber tire car it is mostly about rotation. Going up on the rear til I like the amount of ratation or freeness in the middle of the corner. On my foam car it was more of raising equally til I was happy wiht the way the car carved the corner. The only other thing that I changed on my foam car was rear toe. I do feel like as I have raised the rear roll centers that it has always given a better freeness to the car, and a better rotation.
Anybody else have an opinion?
RedRocket
So maybe for rubber tires on asphalt we can say:
low traction: use low roll centers because this will allow car to roll more and put more weight on tires and generate most grip?
Med traction: use low roll centers plus 1-1.5mm shims under the blocks
high traction: use high roll centers to avoid traction rolling?
11-24-2008, 08:30 PM
#8533
So you are trying to say that low roll center gives more grip? high roll center less grip?
So maybe for rubber tires on asphalt we can say:
low traction: use low roll centers because this will allow car to roll more and put more weight on tires and generate most grip?
Med traction: use low roll centers plus 1-1.5mm shims under the blocks
high traction: use high roll centers to avoid traction rolling?
So maybe for rubber tires on asphalt we can say:
low traction: use low roll centers because this will allow car to roll more and put more weight on tires and generate most grip?
Med traction: use low roll centers plus 1-1.5mm shims under the blocks
high traction: use high roll centers to avoid traction rolling?
RedRocket
11-25-2008, 02:44 PM
#8534
from what I've noticed, on med traction asphalt, when running the following with a spool:
1) Low rear roll center + 1mm / low front roll center= rear has more traction than front end, and the car will push on entry and exit. Not very responsive. Car is stable and good for bigger open flowing tracks.
2) Low rear roll center/ low front roll center= car is stable, smooth, and would be good for a open flowing track as well, but here the rear is a bit looser than level 1, and so it gains a bit more front end traction and will turn in a bit better.
3) Low rear roll center+1mm shims/high front roll centers= increased front end bite/steering and responsiveness. Car turns in much better, and is more responsive...good for med/small tracks as well.
4) Low rear roll center/ high front roll center= with no rear shims, the rear is a bit more free, and you get increased front end bite/steering and reactiveness. Car turns in much better, and is more responsive...good for med/small tracks as well.
According to this, 1 is the least steering, and 4 would give you the most responsive/aggressive feel.
Would love to hear from Larry, Schreff, Mike, and the rest of R pros on what they know on this
1) Low rear roll center + 1mm / low front roll center= rear has more traction than front end, and the car will push on entry and exit. Not very responsive. Car is stable and good for bigger open flowing tracks.
2) Low rear roll center/ low front roll center= car is stable, smooth, and would be good for a open flowing track as well, but here the rear is a bit looser than level 1, and so it gains a bit more front end traction and will turn in a bit better.
3) Low rear roll center+1mm shims/high front roll centers= increased front end bite/steering and responsiveness. Car turns in much better, and is more responsive...good for med/small tracks as well.
4) Low rear roll center/ high front roll center= with no rear shims, the rear is a bit more free, and you get increased front end bite/steering and reactiveness. Car turns in much better, and is more responsive...good for med/small tracks as well.
According to this, 1 is the least steering, and 4 would give you the most responsive/aggressive feel.
Would love to hear from Larry, Schreff, Mike, and the rest of R pros on what they know on this
11-26-2008, 03:23 AM
#8535
IMO a higher hinge pin will give more grip with rubber tire on carpet. My thought with the type r on rubber is the stiffer you go (springs, bars, rollcenter) and the flatter the car stays, the more sidebite it will have as the tires will have the weight of the car forcing them into the track, as opposed to having alot of body roll and a lazy car. For rubber i always run high front pins, and play with the rear a bit from none to 3 #4 washers. The issue is that with a higher rear pin, my car tends to traction roll on high bite carpet, so i usually run it as high as is comfortable to drive.
Disclaimer is i run very little on pavement, so i have no idea if stuff does he same thing...consult Larry or Jason for that.
Disclaimer is i run very little on pavement, so i have no idea if stuff does he same thing...consult Larry or Jason for that.