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I finally have the CR01 going and from a stand still to power on (even light trigger) it lurches to the left rear and when going under speed the body leans to the left even though it’s level when stopped

i cannot figure out why....anyone else had this?

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It's commonly referred to as 'torque twist' - it's basically the same action that makes a Wild Willy wheelie; the gearbox rotating around the outputs.
Recently, some manufacturers have used opposed-rotation driveshafts to minimize torque twist and, provided all four wheels have equal traction, it works great.

It's not a difficult fix to implement at the design stage, just most manufacturers took the easy route and didn't bother until the last year or so

 

This is the simplest way - the driveshafts rotate directly against each other
This was on TLT axles and the rear axle needed to be installed upside down in order for the wherels to rotate correctly

Another option is feed the rear output into a transfer case to reverse the final rotation, or even feed it into a differential - that'd also reverse the rotation.

img169_24032005185132_10_1100_.jpg

 

 

On custom scalers you can usually reduce the twist by changing the shock springs, or the angle of the shocks which are most affected (probably back left) but any tweaks to reduce the twist will also have an affect on the suspension action on that corner too

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torque twist can be reduced by increasing longitudinal rotational inertia of the car. this can be done by

re-distributing the masses of components (e.g. place the battery transversely rather than longitudinally)

adding more weights at outer most parts (e.g. use heavy alloy wheels)

reducing weights of longitudinally rotating parts (e.g use light weight gears / main drive shafts)

it’s all about physics.....

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2 hours ago, pourMoneyIntoSea said:

adding more weights at outer most parts (e.g. use heavy alloy wheels)

Adding weight to the wheels does nothing to counter torque twist as it's the chassis moving in relation to the axles, around the driveshafts

You could put wheels weighing 10kg on each corner and that wouldn't stop the chassis moving at all.

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CR's have built in away bars. Yours may not be installed 

If you don't have a manual you may download one from Tamiyausa.com or if outside the US another country distributor page..or on here under resourcy too.

Anyway the parts are color coded, gold, silver and a third one for light, med heavy. Heavy went in the rear IIRC.

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38 minutes ago, geniusanthony said:

CR's have built in away bars. Yours may may not be installed 

If you don't have a manual you may download one from Tamiyausa.com or if outside the US another country distributor page..or on here under resourcy too.

Anyway the parts are color coded, gold, silver and a third one for light, med heavy. Heavy went I'm the rear IIRC.

Yeah I running gold front (medium) and black rear {soft)

 

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The Bronco kit that I turned into a Blackfoot is setup as silver rear and gold front, when swapped I would think they would exacerbate the behavior. I would be curious on your thoughts if you tried to swap them, Should help keep the rear end controlled and let the front end waggle around a bit instead. I've ran one without any sways and a castle brushless and  thought it waggled around quite a bit but nothing excessive considering the anticipated use. Lifted the front wheel on tight turns but no rolling which is good.

 

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5 hours ago, geniusanthony said:

The Bronco kit that I turned into a Blackfoot is setup as silver rear and gold front, when swapped I would think they would exacerbate the behavior. I would be curious on your thoughts if you tried to swap them, Should help keep the rear end controlled and let the front end waggle around a bit instead. I've ran one without any sways and a castle brushless and  thought it waggled around quite a bit but nothing excessive considering the anticipated use. Lifted the front wheel on tight turns but no rolling which is good.

 

I gave it a try and it didn't do much but did take a bit little bit out

I tweaked a few other things like the shock oil (went up to 40WT) and also modified the throttle curve on my radio

still does it as people said its natural but I have calmed it down it has seem to feel less capable on my backyard small proving ground :lol:

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21 hours ago, TWINSET said:

Adding weight to the wheels does nothing to counter torque twist as it's the chassis moving in relation to the axles, around the driveshafts

You could put wheels weighing 10kg on each corner and that wouldn't stop the chassis moving at all.

wheels are outermost parts of the car. using heavier wheels increases rotational inertia about longitudinal axle.

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Perhaps understand the issue before copy/pasting

The CHASSIS rolls to one side under power due to the rotational force from the gearbox acting against the axle - Because the axle doesn't move in relation to the chassis until one wheel lifts or one shock is compressed, the weight of anything at the end of the axle has absolutely no effect on what the chassis does until the suspension has bottomed out on the compressed side.

The suspension articulating is what allows the chassis to move, not how heavy the wheels are at the end of the axles.

If you watch that video you will see the chassis rolls to the left even with all four wheels on the table, therefore wheel weight doesn't affect chassis roll/torque twist in the slightest

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What springs are you running?  I noticed in a lot of videos of CR01s with stock height springs the body leans quite a bit more than my CR01 with the short barrel springs.

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10 hours ago, TWINSET said:

Perhaps understand the issue before copy/pasting

The CHASSIS rolls to one side under power due to the rotational force from the gearbox acting against the axle - Because the axle doesn't move in relation to the chassis until one wheel lifts or one shock is compressed, the weight of anything at the end of the axle has absolutely no effect on what the chassis does until the suspension has bottomed out on the compressed side.

The suspension articulating is what allows the chassis to move, not how heavy the wheels are at the end of the axles.

If you watch that video you will see the chassis rolls to the left even with all four wheels on the table, therefore wheel weight doesn't affect chassis roll/torque twist in the slightest

u r right. I got yr point.

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