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Old 05-19-2010, 09:35 AM   #1
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Exclamation CRAZY : Huge left understeer

Hey guys,

I have just got my car all up and running now and its insanely fast but a problem i have been have for a long time is mega understeer but only when turning left. Right is perfect and just sits theres and loops around at a million miles an hour but i put it on full lock left then hit throttle and the car just goes in a straight line at high speed, from stand still and moving it just unders a huge amount!

Slowly i can turn in circles but thats all, and mid drift i cant change direction because it just understeers. I have a Tamiya EVO 4 and im unsure what the issue is, i have tried to put weight under the left steering arm but to zero affect!

Some help would be great, this problem has been present for so long and i cant shake it. All my alignment is equal on both sides,
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Old 05-19-2010, 11:27 AM   #2
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Have you set the tweak? Sounds like the car is tweaked.
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Old 05-19-2010, 11:35 AM   #3
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Originally Posted by Luke-TBCS View Post
Hey guys,

I have just got my car all up and running now and its insanely fast but a problem i have been have for a long time is mega understeer but only when turning left. Right is perfect and just sits theres and loops around at a million miles an hour but i put it on full lock left then hit throttle and the car just goes in a straight line at high speed, from stand still and moving it just unders a huge amount!

Slowly i can turn in circles but thats all, and mid drift i cant change direction because it just understeers. I have a Tamiya EVO 4 and im unsure what the issue is, i have tried to put weight under the left steering arm but to zero affect!

Some help would be great, this problem has been present for so long and i cant shake it. All my alignment is equal on both sides,
Could be a hundred different things. We need a full list of your setup settings.

The only thing I can think of that would create such a dramatic issue, would be your right front wheel binding, when you turn your steering to the left. A tweak issue wouldn't cause what you are seeing.
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Old 05-19-2010, 05:20 PM   #4
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check your steering lock left to right
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Old 05-19-2010, 06:21 PM   #5
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check your steering lock left to right
Running a Tamiya EVO 4

Front diff : Ball type
Front suspension : Tamiya soft yellows
Camber : -7 degrees
Toe in : 1

Rear diff : Custom 1.7 countersteer yokomo gears
Rear suspension : Tamiya medium orange
Camber : -5 degrees
Toe in : 3

There is no big shaft play and the whole drive train is very smooth.
The front steering arms have been shaved to allow for more lock, the universal front drive shafts don't seem to be binding on anything that i can see.
The front diff, i have tried my one way and also this ball diff both with the same problem.
When driving it at very low speed the car turns left and right on full lock no problems, its when i give it some proper throttle it unders when steering left.
When testing it manually and pushing it on the ground i put the wheels on full lock then push it and its perfect turning to the right then just unders and continues in a straight line when on full lock left.

It's nothing to do with servo lads it's understeering issues caused by something else, it has full lock on both sides and centered but still no dice.

I have been pushing it across the ground to test it manually and on full lock right it turns fine in that direction when i push it then I push it with full lock left and it just goes straight. This is the same as when i test it driving it. Then I take the back left shock out from the understeering side of the car and it turns fine in both directions when pushed.

So with no rear left shock it's perfect but once back in mega under again.

First thing i could think of would be binding on the left side but i have tried many times to find a bind and no problem, i put it on full lock and throttle on and the front left and right wheels seem to spin the same speed and no delays or binding from either one.

Thx for your guys help really need some!!!

Last edited by Luke-TBCS; 05-19-2010 at 07:14 PM.
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Old 05-19-2010, 07:00 PM   #6
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Quote:
Originally Posted by Luke-TBCS View Post
Front
Camber : 7 degrees
Toe in : 1

Rear
Camber : 5 degrees
Toe out : 3
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Old 05-19-2010, 07:09 PM   #7
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Sorry its ment to be minus -7 and -5 camber and 3 degrees toe in on the rear not toe out!!!

I forget to mention this was a drift car, running the countersteer mods, in any case it should still not be getting this understeer. If it was setup like a grip rc with less camber etc then it would still have these problems, i know because i have put everything back to stock settings alignment wise.
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Old 05-20-2010, 07:36 PM   #8
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sounds like its your countersteer..... i have a hard time keeping my car straight alot of times and it seems to always wanna pull right...

otherwise check your diffs.... maybe ones letting go weirdly
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Old 03-17-2012, 08:55 AM   #9
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Quote:
Originally Posted by Luke-TBCS View Post
Hey guys,

I have just got my car all up and running now and its insanely fast but a problem i have been have for a long time is mega understeer but only when turning left. Right is perfect and just sits theres and loops around at a million miles an hour but i put it on full lock left then hit throttle and the car just goes in a straight line at high speed, from stand still and moving it just unders a huge amount!

Slowly i can turn in circles but thats all, and mid drift i cant change direction because it just understeers. I have a Tamiya EVO 4 and im unsure what the issue is, i have tried to put weight under the left steering arm but to zero affect!

Some help would be great, this problem has been present for so long and i cant shake it. All my alignment is equal on both sides,

Hi Luke
I'm facing the same problem, i worked in a local hobby shop and involved in maintenance service, this issue is my main concern now, I've found some solutions like unequal spring stiffness that wont make the weight transfer to the sides or rear to front but fixing it is not the solution for all scenarios.

now am having the problem with a nitro rs4, but the weird thing it wasn't understeering until it took a strong front hit. After i changed the damaged parts and reset the car setup (it have a fixed linkages, so the camber, caster and toe in/out is fixed and for sure equal), it now horribly understeers to left! .. tried the suspensions sittings with no results.

A close inspection showed the chassis is bent a Little bit and am not sure if this what causes the problem!

Any progress with your problem?, plz inform me.

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Old 03-17-2012, 07:28 PM   #10
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Quote:
Originally Posted by Luke-TBCS View Post
Sorry its ment to be minus -7 and -5 camber and 3 degrees toe in on the rear not toe out!!!

I forget to mention this was a drift car, running the countersteer mods, in any case it should still not be getting this understeer. If it was setup like a grip rc with less camber etc then it would still have these problems, i know because i have put everything back to stock settings alignment wise.
Why such high camber?

In Tc's we normally run -1.5 to -2.5 etc

Something is binding by the sound of it.

Take corner of the car apart and check for thigs not moving/spinning freely etc.
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Old 03-17-2012, 08:57 PM   #11
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Quote:
Originally Posted by Skiddins View Post
Why such high camber?

In Tc's we normally run -1.5 to -2.5 etc

Something is binding by the sound of it.

Take corner of the car apart and check for thigs not moving/spinning freely etc.
Its a drift car, those kinds of camber settings are fairly common. Also, who would use countersteer in a tc.
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Old 03-18-2012, 10:17 AM   #12
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Just want to make one quick point..

If you car is not working on one side, look at the other side of the car.

ie. you said your car wont turn left, so look at the right side of the suspension. Not the left side as you posted earlier.


Take you shocks off the chasis, and make sure the low suspension arms can fall freely, sounds like a bind in the RF.


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Old 03-19-2012, 02:03 AM   #13
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otherwise check your diffs.... maybe ones letting go weirdly

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