R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 01-04-2012, 02:34 AM   #1141
Tech Champion
 
CraigM's Avatar
 
Join Date: Mar 2007
Location: Sydney, Australia
Posts: 7,009
Trader Rating: 34 (100%+)
Default

Quote:
Originally Posted by CraigM View Post
Can you explain how changing the link length changes the roll centre if the angle stays the same?
Quote:
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.
__________________
www.facebook.com/mcpheerc
CraigM is offline   Reply With Quote
Old 01-04-2012, 03:04 AM   #1142
Tech Apprentice
 
Join Date: Aug 2008
Posts: 52
Default

Quote:
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....
yokfans is offline   Reply With Quote
Old 01-04-2012, 07:01 AM   #1143
Tech Adept
 
Join Date: Jan 2010
Posts: 157
Send a message via AIM to Matt W
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?
Matt W is offline   Reply With Quote
Old 01-04-2012, 07:18 AM   #1144
Tech Elite
 
M-Technic's Avatar
 
Join Date: Sep 2007
Location: Palm Beach, FL
Posts: 2,562
Trader Rating: 15 (100%+)
Default

Quote:
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.
__________________
RCAmerica | Xray | Hudy | Radiopost | Speed Passion USA | Trinity | P3 Graphics
M-Technic is offline   Reply With Quote
Old 01-04-2012, 07:46 AM   #1145
Tech Master
 
Join Date: Aug 2010
Posts: 1,084
Trader Rating: 30 (97%+)
Default

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
zaraz is offline   Reply With Quote
Old 01-04-2012, 10:07 AM   #1146
Tech Initiate
 
speedyfowler's Avatar
 
Join Date: Jun 2010
Posts: 35
Default

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.
__________________
Steve Fowler
Team Serious Business
Outlaw RC Motorsports / Protoform
Lou's Speedway/Much Hobby/RC Niagara Indoor

Last edited by speedyfowler; 01-04-2012 at 10:30 AM.
speedyfowler is offline   Reply With Quote
Old 01-04-2012, 12:37 PM   #1147
Tech Elite
 
artwork's Avatar
 
Join Date: Sep 2004
Location: Thornton, CO
Posts: 3,094
Trader Rating: 60 (100%+)
Default

Quote:
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
__________________
Sanwa | R1 Wurks | Avid | 2mm Designs
artwork is offline   Reply With Quote
Old 01-04-2012, 12:47 PM   #1148
Tech Champion
 
CraigM's Avatar
 
Join Date: Mar 2007
Location: Sydney, Australia
Posts: 7,009
Trader Rating: 34 (100%+)
Default

Quote:
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
__________________
www.facebook.com/mcpheerc
CraigM is offline   Reply With Quote
Old 01-04-2012, 12:58 PM   #1149
Tech Elite
 
artwork's Avatar
 
Join Date: Sep 2004
Location: Thornton, CO
Posts: 3,094
Trader Rating: 60 (100%+)
Default

Quote:
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!
__________________
Sanwa | R1 Wurks | Avid | 2mm Designs
artwork is offline   Reply With Quote
Old 01-04-2012, 01:19 PM   #1150
Tech Champion
 
CraigM's Avatar
 
Join Date: Mar 2007
Location: Sydney, Australia
Posts: 7,009
Trader Rating: 34 (100%+)
Default

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
__________________
www.facebook.com/mcpheerc
CraigM is offline   Reply With Quote
Old 01-04-2012, 03:40 PM   #1151
Tech Master
 
Join Date: Aug 2010
Posts: 1,084
Trader Rating: 30 (97%+)
Default

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
zaraz is offline   Reply With Quote
Old 01-04-2012, 03:46 PM   #1152
Tech Elite
 
Fred Hubbard's Avatar
 
Join Date: Nov 2001
Location: Inglewood, CA
Posts: 2,711
Trader Rating: 6 (100%+)
Default

Quote:
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.
__________________
Goodwine Racing - RC America - XRAY - HUDY - Sanwa - Motiv - GravityRC - BN Racing
Fred Hubbard is offline   Reply With Quote
Old 01-04-2012, 04:01 PM   #1153
Tech Master
 
ByteStream's Avatar
 
Join Date: Jan 2010
Location: 5280 Raceway
Posts: 1,142
Trader Rating: 2 (100%+)
Default

Quote:
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.
__________________
RCAmerica | Xray | Hudy | KO Propo | Hobbywing HWNA | R1Wurks | BSR Tires
5280 Raceway - www.5280raceway.com
MILE HIGH INDOOR CHAMPS April 20-23rd 2017 @ www.milehighindoorchamps.com
ByteStream is offline   Reply With Quote
Old 01-05-2012, 04:17 AM   #1154
Tech Elite
 
morgoth's Avatar
 
Join Date: May 2010
Location: Belgium
Posts: 2,518
Default

This is a good piece of information
Quote:
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.
__________________
Serpent BeNeLux teamdriver // FX Engines // Nitrolux fuel
My blog: http://scrubbingspeed.wordpress.com
morgoth is offline   Reply With Quote
Old 01-07-2012, 02:59 AM   #1155
NR
Tech Master
 
NR's Avatar
 
Join Date: Aug 2003
Location: Sydney
Posts: 1,535
Trader Rating: 52 (100%+)
Default

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
NR is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Xray T3 2011 entitymugenmtx Electric On-Road 4150 05-19-2014 12:53 PM
Xray T3 2011 New in Box olhipster1 R/C Items: For Sale/Trade 19 08-04-2011 05:27 AM
XRAY T3 2012 bila nk keluar? bravolous Malaysian R/C Racers 8 06-16-2011 11:58 PM
Xray T3 nitro rat Australia For Sale/Trade 22 09-19-2010 03:11 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 01:52 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net