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Xray T3 2012

Old 01-04-2012, 02:34 AM
  #1141  
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Originally Posted by CraigM View Post
Can you explain how changing the link length changes the roll centre if the angle stays the same?
Originally Posted by mdwaeracer View Post
It makes the camber gain slower. numbing that end.
It was a trick question I just wanted to understand why Artwork believed it did.

Changing the link length without changing the link angle relative to the arms has no effect on static RC, it only changes what the RC does as the car rolls. Short links cause the RC to rise as the car rolls, so will roll initially and then stop giving a more reactive feeling, long links cause the RC to stay low as the car rolls, so will roll more mid corner (at that end).

So back to the original question, I would lengthen the front link to make the front end roll more mid corner, and I would not lengthen the rear links unless you want a more stuck rear end.

A 3k rear diff is pretty heavy so I would look for on power steering elsewhere, less front droop is a good place to start and a harder rear sway bar also works well on the xray, less rear toe is good if you need steering in high speed sweepers.
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Old 01-04-2012, 03:04 AM
  #1142  
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Originally Posted by CraigM View Post
It was a trick question I just wanted to understand why Artwork believed it did.

Changing the link length without changing the link angle relative to the arms has no effect on static RC, it only changes what the RC does as the car rolls. Short links cause the RC to rise as the car rolls, so will roll initially and then stop giving a more reactive feeling, long links cause the RC to stay low as the car rolls, so will roll more mid corner (at that end).

So back to the original question, I would lengthen the front link to make the front end roll more mid corner, and I would not lengthen the rear links unless you want a more stuck rear end.

A 3k rear diff is pretty heavy so I would look for on power steering elsewhere, less front droop is a good place to start and a harder rear sway bar also works well on the xray, less rear toe is good if you need steering in high speed sweepers.
ok, thanks to all for your valuable advice. Let me give it a try and let you guys have the report....
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Old 01-04-2012, 07:01 AM
  #1143  
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Default composite shims

Hey,

Thanks for all the explanations on turnbuckle positioning, very useful!!

I was wondering, appart from to save weight and the fact that they are cheaper to produce, why are composite shims used instead of alu ones either side of the wishbones, any ideas?
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Old 01-04-2012, 07:18 AM
  #1144  
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Originally Posted by yokfans View Post
Could anyone help to give me some advice?

The current layout of the track I'm playing contains lots of short straights then U-turns.

My T3 2012 is lacking mid-corner steering and also experiencing on-power push. Seems the rear is dialed too much.

I'm using basic asphalt setup except with 3000t rear diff oil and 1mm inner camber link shim both front & rear. Have tried using smaller deg of diff oil but push even hard.
You might want to try adding more bump steer shims underneath the steering knuckle. Kit setup I believe is 1mm. I was first running 2mm, and now running 3.5mm of shims so the links are parallel to the driveshafts at a 5.2mm front ride height. It had a very noticeable effect on my mid-corner steering. You will have to reset your front toe after adding the shims.
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Old 01-04-2012, 07:46 AM
  #1145  
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when building the 2012 for high grip carpet, what would be a good starting point, build it like the kit, or is there a link to a setup that works well, thanks
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Old 01-04-2012, 10:07 AM
  #1146  
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The kit setup seems to be a good starting point.

Dave Locke ran his stock setup with 600cst F/425cst R with good results at Lou's (high traction carpet, where you race haha). My preference was 575cst F/500cst R.

Last edited by speedyfowler; 01-04-2012 at 10:30 AM.
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Old 01-04-2012, 12:37 PM
  #1147  
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Originally Posted by CraigM View Post
Can you explain how changing the link length changes the roll centre if the angle stays the same?
Longer links lowers the roll center, also less camber gain and typically decreases traction

Shorter links raises the roll center, also more camber gain and typically increases traction
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Old 01-04-2012, 12:47 PM
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Originally Posted by artwork View Post
Longer links lowers the roll center, also less camber gain and typically decreases traction

Shorter links raises the roll center, also more camber gain and typically increases traction
Why do you think link length has an impact on roll centre? It doesn't, read up on how roll centre is calculated and you'll see why
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Old 01-04-2012, 12:58 PM
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Originally Posted by CraigM View Post
Static roll centre is not affected by link length only angle

Camber gain's affect on handling is dependent on static camber and the tyres being used. Too much camber gain will reduce surface contact and result in less grip.
Changing the link length actually does affect the angle even if it is very slight...when we are talking about roll center even the slightest change will have an effect.

Why are you asking questions that you clearly know the answer to...is it to be a jerk?

Just to be fair...please respond to every roll center or link length questions going forward...to save us all the embarrassment. Oh and please include all threads on RCtech...thanks!
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Old 01-04-2012, 01:19 PM
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Not meaning to sound like a jerk, I wanted to understand why you said that - now you have answered because the link angle changes slightly, unless you compensate

There's some great reading on roll centre here
http://users.telenet.be/elvo/3/3.html
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Old 01-04-2012, 03:40 PM
  #1151  
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hi, I do not like taping in my batteries, and was looking at the xray lipo battery graphite strap part number 306163-K, any one have one intalled on their car, how does it work, it says it will not tweek the chassis no matter how tight you screw it in, so those who have it is this a true statement, as it would be a great option for me but not sure about the claim, thanks
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Old 01-04-2012, 03:46 PM
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Originally Posted by zaraz View Post
hi, I do not like taping in my batteries, and was looking at the xray lipo battery graphite strap part number 306163-K, any one have one intalled on their car, how does it work, it says it will not tweek the chassis no matter how tight you screw it in, so those who have it is this a true statement, as it would be a great option for me but not sure about the claim, thanks
Fiber or double-sided tape is the best solution.
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Old 01-04-2012, 04:01 PM
  #1153  
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Originally Posted by zaraz View Post
hi, I do not like taping in my batteries, and was looking at the xray lipo battery graphite strap part number 306163-K, any one have one intalled on their car, how does it work, it says it will not tweek the chassis no matter how tight you screw it in, so those who have it is this a true statement, as it would be a great option for me but not sure about the claim, thanks
I bought one when I had a T3'10 and never ended up using it. While it does not tweak the chassis, it also does not keep the battery from moving side to side.

Use tape.
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Old 01-05-2012, 04:17 AM
  #1154  
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This is a good piece of information
Originally Posted by http://home.scarlet.be/~be067749/58/
In general, you could say that the angle of the upper link relative to the A-arm determines where the roll center is with the chassis in its neutral position, and that the length of the upper link determines how much the height of the RC changes as the chassis rolls. A long, parallel link will locate the RC very low, and it will stay very low as the car corners. Hence, the car (well at least that end of the car) will roll a lot. An upper link that's angled down, and very short will locate the RC very high, and it will stay high as the chassis rolls. So the chassis will roll very little. Alternatively, a short, parallel link will make the car roll a lot at first, but as it rolls, the tendency will diminish. So it will roll very fast at first, but it will stop quickly. And a long link that's angled down will reduce the car's tendency to roll initially, but as the chassis rolls it won't make much of a difference anymore.

In terms of car handling, this means that the end where the link is angled down the most (highest RC) has the most grip initially, when turning in, or exiting the corner, and that the end with the lowest RC when the chassis is rolled will have the most grip in the middle of the corner. So if you need a little more steering in the middle of the corners, lengthen the front upper link a little. (Be sure to adjust camber afterwards) If you'd like more aggressive turn-in, and more low-speed steering, either set the rear upper link at less of an angle, or increase the front link's angle a little.
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Old 01-07-2012, 02:59 AM
  #1155  
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Can anyone please tell me where the kit recommends starting with droop?

I forgot and cannot find the setup sheet that came with the car.

Cheers
Nathan
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