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Old 04-21-2015, 08:14 AM
  #2491  
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My front arm seems too tight with all 3 shims. I have 2 of the 1 mm ships in front and 2mm in back. did you remove one of the 1mm shims out?
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Old 04-21-2015, 10:59 AM
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Originally Posted by wichitafc98 View Post
My front arm seems too tight with all 3 shims. I have 2 of the 1 mm ships in front and 2mm in back. did you remove one of the 1mm shims out?
It may be a little snug while new but should still move freely once installed. Make sure your inserts/pills are pushed all the way in.
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Old 04-21-2015, 08:16 PM
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Originally Posted by masher81 View Post
Why lower the rear hub.. then have to use spacer to raise the link again?
When Kurt Kellum points me in the right direction I don't ask why. That small change just made the car better. Has to do with roll center. But I do see your point.
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Old 04-21-2015, 08:23 PM
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Originally Posted by Frank L View Post
When Kurt Kellum points me in the right direction I don't ask why. That small change just made the car better. Has to do with roll center. But I do see your point.
What spacers are people using under the camber link pivot ball to raise it up 2mm? Do Xray make any?
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Old 04-21-2015, 08:48 PM
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Originally Posted by Frank L View Post
When Kurt Kellum points me in the right direction I don't ask why. That small change just made the car better. Has to do with roll center. But I do see your point.
This rear setup is interesting, I may have to try it.

I haven't been following the thread lately, but what I was noticing last summer was the rear end dumping over at corner exit. I thought it was a rear end issue... I tried lowering and raising the roll centers, changing camber gain, etc with little effect.

I decided the issue is not the rear end, but in the front end... and then remembered something a friend who runs an MBX7 told me. When we used to run 1/12th scale pan, the front end had a tuning option called "reactive caster" which effectively added caster as the outside wheel's suspension compresses going into the corner thus creating more steering at mid to corner exit.

The reactive caster was created by lowering the front of the upper, inside hinge pin. Zero reactive caster is where the upper and lower arms are parallel. So if you notice on the XB8, consider the lower hinge pin as the plane of reference, the upper hinge pin is leaning down at the front which effectively gives the XB8 reactive caster. When I attempted to "correct" this by changing the angle of the upper hinge pin to be more parallel with the lower hinge pin, I saw a dramatic increase in the stability of the car. I used 1 inside/down in the rear, 1 inside up in the front... which is obviously the maximum I could accomplish. This doesn't completely remove the reactive caster, but significantly helps stabilize the car.

The car with this configuration almost had a push to it... it never felt like it would step out. I think I want to try adding a bit more reactive caster (like by trying 0.5's instead of 1's) and see what happens. I also found that making the upper A-arms shorter made the car edgier (I did it drastically by moving to 1 outside instead of inside), but I think going with the 0.5 up inside in the front, and 0.5 down inside in the rear will give a bit more exit steering.

Long story short, I just don't think the changes that need to be made are in the rear end as much as the front end.
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Old 04-21-2015, 09:07 PM
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Originally Posted by stricko View Post
What spacers are people using under the camber link pivot ball to raise it up 2mm? Do Xray make any?
They came with the car. And yes x ray does make them.
XRA353380 1mm
XRA353381 2mm
(They are black alum)

Another interesting spot to add them is at the front upper pivot ball - adding a 1-2mm shim dramatically numbs the steering. (Same as lowering the front upper pin in the front)

Kuruption - very interesting.
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Old 04-21-2015, 09:08 PM
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Thanks Frank, I'll have to take a look through my spares.
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Old 04-22-2015, 09:43 AM
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Originally Posted by Frank L View Post
When Kurt Kellum points me in the right direction I don't ask why. That small change just made the car better. Has to do with roll center. But I do see your point.
Cool. I don't know the space difference between the holes on the upright but, maybe doing it this way is like a in-between of the 2 locations? Where the overall roll center is somewhere between the 2 holes on the upright.
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Old 04-22-2015, 02:30 PM
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Originally Posted by masher81 View Post
Cool. I don't know the space difference between the holes on the upright but, maybe doing it this way is like a in-between of the 2 locations? Where the overall roll center is somewhere between the 2 holes on the upright.
Changing the hub also changes the position of the wheel relative to the ground and the angle of the driveline. Changing just the camber link leaves the wheel/ driveline angle the same.
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Old 04-22-2015, 05:52 PM
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Originally Posted by wichitafc98 View Post
My front arm seems too tight with all 3 shims. I have 2 of the 1 mm ships in front and 2mm in back. did you remove one of the 1mm shims out?
You are right that running all 3 is a very tight fit. If you want to run all 3 an option is to dremel about .5mm off the arm front or rear, which ever you prefer. Just do it the same on both sides. Another option is Mugen makes these clips for their car in different sizes. .9, 1, 1.1, 1.2, 1.4 and 1.6 and 2mm. You can use a combination of these.
http://www.amain.com/rc-cars/mugen-s...0135-b/p246406
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Old 04-22-2015, 06:24 PM
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Originally Posted by 3DRCRACER View Post
You are right that running all 3 is a very tight fit. If you want to run all 3 an option is to dremel about .5mm off the arm front or rear, which ever you prefer. Just do it the same on both sides. Another option is Mugen makes these clips for their car in different sizes. .9, 1, 1.1, 1.2, 1.4 and 1.6 and 2mm. You can use a combination of these.
http://www.amain.com/rc-cars/mugen-s...0135-b/p246406

That is great thanks
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Old 04-22-2015, 11:31 PM
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Default Please i need some help.

Does anyone going to answer my questions and help me with that please? I'm going to hit the track on saturday.

1. Do we have some combinations working together for the rear camber link (shock tower - rear hub)? Or can mess up everything? And also what length i must do for the camber? to have 3 degrees? I don't have a setup port.

2. Some questions here about shock absorbers setup. Anyone having the experience on that ?
a. When to use different shock piston, e.g 6 hole or 10 hole that we have in the kit ?
b. What is the effect of piston hole size?
c. When to use flat piston? Why we don't use flat pistons ?
d. What is the correct way of shocks setup? Choose piston and spring and then adjust for the oil or what?

3. What will be the effect of the spacers on front upper arms? What can achieve by moving the arm forward and backwards?
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Old 04-23-2015, 12:19 AM
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Originally Posted by djbxp View Post
Does anyone going to answer my questions and help me with that please? I'm going to hit the track on saturday.

1. DThe e have some combinations working together for the rear camber link (shock tower - rear hub)? Or can mess up everything? And also what length i must do for the camber? to have 3 degrees? I don't have a setup port.

2. Some questions here about shock absorbers setup. Anyone having the experience on that ?
a. When to use different shock piston, e.g 6 hole or 10 hole that we have in the kit ?
b. What is the effect of piston hole size?
c. When to use flat piston? Why we don't use flat pistons ?
d. What is the correct way of shocks setup? Choose piston and spring and then adjust for the oil or what?

3. What will be the effect of the spacers on front upper arms? What can achieve by moving the arm forward and backwards?
http://forum.teamxray.com/xform/inde...setup=xb8_2015

Try this setup. Very stable car.

Fewer piston holes with bigger diameter gives less pack and visa versa.

Not sure about flat pistons. As I read it, you are new to these cars, so go out on the track and drive instead of go into small details.

The shocks reduses the springs movements so you can't have too thin oil for hard springs and visa versa.

Move the front link forward gives you more offpower steering aaaand... visa versa

Don't have the measurements on the links etc. You need to have a camber gauge and a one of those digital measurering thinks... name? - that's "skydelære" if you speak Danish…

Last edited by Lille-bror; 04-23-2015 at 12:37 AM.
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Old 04-23-2015, 01:54 AM
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Thank you my friend. I will go with your setup. Thanks a lot, wish you all the best.
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Old 04-23-2015, 06:45 AM
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Originally Posted by djbxp View Post
Thank you my friend. I will go with your setup. Thanks a lot, wish you all the best.
Glad to help

THEGuide is a brilliant tool to learn about setup
http://api.viglink.com/api/click?for...om%2Fpage%2F76

...and it's digital caliber
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