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Old 03-07-2012, 11:13 AM   #1
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Smile Loosing the rear end when braking and turning ?

Hi guys.

I am the proved owner of an Yokomo 1/10 MR4 BD TC.
It is a reat car, but I am experince some problems with the rear end. I run on carpet, and when I brake and turn, I almost loses my rear end.
Any one got some surgestion on what I can try to adjust to eliminate this problem.

For setup info, I can tell that I run a gear diff rear, Ball diff front. Ridehight 5 mm. Downstop in front 6, and 5 in rear.

Shocks are filled with 550 viscosity oil.

And a bonus info could be, that it is a small track, with a lot off 180 turns, and few straights.

Hope someone have an surgestion.
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Old 03-07-2012, 11:30 AM   #2
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Have all breaking done before you start turning. You could also stiffen the front springs and add anti dive to help out.
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Old 03-07-2012, 11:34 AM   #3
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Quote:
Originally Posted by Shock Tower View Post
Hi guys.

I am the proved owner of an Yokomo 1/10 MR4 BD TC.
It is a reat car, but I am experince some problems with the rear end. I run on carpet, and when I brake and turn, I almost loses my rear end.
Any one got some surgestion on what I can try to adjust to eliminate this problem.

For setup info, I can tell that I run a gear diff rear, Ball diff front. Ridehight 5 mm. Downstop in front 6, and 5 in rear.

Shocks are filled with 550 viscosity oil.

And a bonus info could be, that it is a small track, with a lot off 180 turns, and few straights.

Hope someone have an surgestion.
You make no mention as to what springs, front and rear camber and toe settings. also where are the shocks positioned? seems the shock oil is a little thick for my taste.....but here is a setup sheet you can try. although it is in german i am sure you can figure out most of it...
dampfer = shock
sturz= droop
also what tires and are you using additive ?

http://www.petitrc.com/reglages/yoko...etup200710.htm
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Old 03-07-2012, 12:54 PM   #4
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Default More info about my current setup.

Okey, I can see there is missing some informations.

Running with standard Yokomo white springs in front, blue in rear. Standard setup following the manual.
Camber 2 deg. In front and rear. TOE settings 0 in front, 3 in rear.
Shocks are positioned in number 3 from left to right both in front and rear.
Tires are Schumacher SOREX 28R?

Hopes this helps.
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Old 03-07-2012, 01:11 PM   #5
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Definitely go with heavier springs in the front. Seems those springs are 9.7lb in the front and 10.9lb in the rear????

I'm not very familiar with carpet setups but it seems you have too much steering going into the turns and stiffer springs will help that.

Another thought, can you adjust Dual Rate on your transmitter? I tend to turn mine down to 85% or so on an Airtronics M8. That helps me fine tune my steering input...
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Old 03-07-2012, 01:19 PM   #6
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Default Loosing the rear end on Yokomo

Could be that i need to go for stiffer springs in the front. Anywhere I can see a chart with colour codes ? I got green, red springs.

And Yes, I tend to have too much steering in corners. So could be to turn down the dual rate, but what is it ?
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Old 03-07-2012, 01:25 PM   #7
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http://www.rctech.net/forum/electric...ing-rates.html

Third post down is the cut and paste, however, if you go to the yokomo website you can probably get better/up to date information.

As for dual rate, hopefully you have the manual to your transmitter?

At the very least, switch the front and rear springs and see if that helps. Then you'll know you are heading in the right direction. But honestly, a full set of springs comes in very handy when racing any kind of rc car.
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Old 03-07-2012, 03:37 PM   #8
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I have exactly the same car as you, and the "problem" is very simple to identify - I have never liked cars that have a one way.

I run a spool axle in the front, and I have swapped the one way gear adaptor on the spur gear shaft for the fixed gear drive adaptor (BD 630)

http://kshobby.com/index.php?route=p...product_id=151
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Old 03-07-2012, 03:42 PM   #9
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Another thought, can you adjust Dual Rate on your transmitter? I tend to turn mine down to 85% or so on an Airtronics M8. That helps me fine tune my steering input...[/QUOTE]

I had the same issue when I started running touring car again, turning down the DR helped cure almost 90% of the problem.
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Old 03-07-2012, 03:48 PM   #10
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Quote:
Originally Posted by Shock Tower View Post
Could be that i need to go for stiffer springs in the front. Anywhere I can see a chart with colour codes ? I got green, red springs.

And Yes, I tend to have too much steering in corners. So could be to turn down the dual rate, but what is it ?
The best way I can describe dual rate is that if you have your steering set at "full lock" and hold down, for example, full right steering and you decrease the dual rate you will see the full lock decrease, thus limiting how much turn in you have at full lock. In my experience I greatly helps smooth out your chassis preventing the ass end from coming loose. Usually dual rates selector is found above the throttle as a dial.
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Old 03-07-2012, 04:08 PM   #11
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you need heavier springs on the front end. if your on a carpet track, you should be running diffs front and rear, and otional, you could run a spool..but you will have the same problems. also run thicker front shock oil. this will slow down the suspension movement, making it more fluid on a tight track. also put a degree or 2 of front toe into the chassis. front toe will help with straighline stability but will also help set the outside tire so that the car will slightly put in corners.
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Old 03-07-2012, 04:19 PM   #12
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you need heavier springs on the front end. if your on a carpet track, you should be running diffs front and rear, and otional, you could run a spool..but you will have the same problems. also run thicker front shock oil. this will slow down the suspension movement, making it more fluid on a tight track. also put a degree or 2 of front toe into the chassis. front toe will help with straighline stability but will also help set the outside tire so that the car will slightly put in corners.
I have found that the spool actually adds to a push or tight condition not a loose one. Plus it really helps pull out of the turns.

Wouldn't toe in add to the corner entry grip thus working the back even harder? Usually 0.5 toe out is a good setting. Rear toe in would help with the rear stability. Honesty it sounds like too much weight is being shifted forward and the rear is getting too light to hold the track. I agree that heavier front springs will definitely help. Shock oil not as much as the springs but it will help too.
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Old 03-07-2012, 04:28 PM   #13
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Less rear droop so there is less weight transfer to the front.
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Old 03-07-2012, 04:30 PM   #14
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you would be correct. but this persons driving style and talk leads me to believe that hes new to onroad.. putting the spool in the front would mean that if he went into turn and hit the brakes, the front end would act as a boat anchor and would make it loose. if you have a spool in your car, try to overdrive/over brake in corners and you will see what i mean. the shock oil will slow down the action of the suspension, thus slowing down how fast the car acts when you turn the wheels. i have personally set up someones car that lives in Austrailia, by him showing me 2 videos, and him doing exactly what i suggested. this guy has sent me messages sayin that there is guys that want to pay him for the setup..just sayin that im pretty good at what i do. plus it dont hurt that i used to setup real race cars for circuit racing!

ps: not tryin to toot my own horn, just lettin everyone here know that i don know what im talkin about
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Old 03-07-2012, 04:37 PM   #15
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You can also lower the braking power a tiny bit.
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