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Old 03-12-2014, 12:37 PM   #121
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thanks mike, i didnt think of the pan car reference, but i get it now! appreciate the help
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Old 03-12-2014, 12:45 PM   #122
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Originally Posted by gocoogs View Post
Martin,

On the Awesomatix EVO, there 2 are upper camber links that adjust caster and camber in unison. There are also options to place a different number of shims under each link to adjust roll centers. I have looked at several set up sheets online for this car and some have a different number of shims in the top camber links FF and FR. I can not get my head around what sort of set up adjustment this is... different shims in the two front upper camber links would add what value. In my head, it doesnt change the angle of the shock or arm, it doesn't add anti dive or pro dive... what affect would it have to have different shims in two spots on the front top deck camber/caster link?
As Mike mentioned it provides reactive caster something pan cars have been using for a long time know. What happens when you make the front links lower than back is caster is removed as the tire moves upward. So as the car starts to lean into a corner and reaches it's max movement caster is removed. So if you want to equate this back to Martins app, think about the static caster adjustment and what effect removing caster would be on corner entry and mid corner.

It's something I've experimented with a fair amount on the Awesomatix, equal upper links and angled. I personally like the reactive caster and run it on both my cars.
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Old 03-12-2014, 04:48 PM   #123
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Originally Posted by faifaisalfal View Post
Hi Martin,

How do we set the anti roll bar properly so that both side is balance? How much play is needed before the other side move?
I would imagine there are some different approaches out there, but my view is that the set screws that hold the swaybar in place should not restrict the swaybars ability to be twisted, while at the same time not allow the swaybar to move around much. So I set them up so the set screws barely touch the swaybar and then back off a quarter turn.

In terms of balancing the swaybars, you first need to make sure there is nothing binding in the suspension travel. Then lift up the left arm until the right arm starts to lift. Measure the height of the left arm. Now switch sides and lift up the right arm until the left arm starts to lift, and measure the height of the right arm. Make adjustments on the links until you can match the height on both sides.


Quote:
Originally Posted by gocoogs View Post
Martin,

On the Awesomatix EVO, there 2 are upper camber links that adjust caster and camber in unison. There are also options to place a different number of shims under each link to adjust roll centers. I have looked at several set up sheets online for this car and some have a different number of shims in the top camber links FF and FR. I can not get my head around what sort of set up adjustment this is... different shims in the two front upper camber links would add what value. In my head, it doesnt change the angle of the shock or arm, it doesn't add anti dive or pro dive... what affect would it have to have different
shims in two spots on the front top deck camber/caster link?
As Mike indicated this will give you reactive caster. To add to his explaination, the spacers under the FF camber link will primarily affect the roll center, and the spacers under the FR link will primarily affect the caster. For example the more spacers your add to the FR link the less caster you will have under suspension compression. Also the more spacers you add to the camber link the lower the roll center will be.

It is for sure an interesting approach. However I am not sure I like the idea of not being able to adjust the roll center and caster independently of each other, but it is a fairly proven approach as used in pan cars.
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Old 03-12-2014, 09:46 PM   #124
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Quote:
Originally Posted by Martin Crisp View Post
I would imagine there are some different approaches out there, but my view is that the set screws that hold the swaybar in place should not restrict the swaybars ability to be twisted, while at the same time not allow the swaybar to move around much. So I set them up so the set screws barely touch the swaybar and then back off a quarter turn.

In terms of balancing the swaybars, you first need to make sure there is nothing binding in the suspension travel. Then lift up the left arm until the right arm starts to lift. Measure the height of the left arm. Now switch sides and lift up the right arm until the left arm starts to lift, and measure the height of the right arm. Make adjustments on the links until you can match the height on both sides.
Hi Martin,

Thanks for the reply. But I still have some question regarding sway bar.

Will there be any difference between a sway bar that is set with arm movement of maybe 7mm on both sides and a sway bar setting that has arm movement of maybe 3mm? Is the amount of movement important or is this something that we don't have to worry about as long as both side are equal?

I'm asking this because I know some car has more sensitive(less arm movement) sway bar compared to others.
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Old 03-13-2014, 07:41 AM   #125
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Quote:
Originally Posted by faifaisalfal View Post
Hi Martin,

Thanks for the reply. But I still have some question regarding sway bar.

Will there be any difference between a sway bar that is set with arm movement of maybe 7mm on both sides and a sway bar setting that has arm movement of maybe 3mm? Is the amount of movement important or is this something that we don't have to worry about as long as both side are equal?

I'm asking this because I know some car has more sensitive(less arm movement) sway bar compared to others.
I assume by arm movement you mean the vertical movement at the end of the swaybar on both sides?

If the vertical movement is less then that would typically mean the point where the swaybar link attaches to the swaybar is further inboard. If this is the case then the swaybar is effectively stiffer (to use your terms - more sensitive).

Most RC car designs that I am familiar with tend to have the swaybar links mounted in about the same spot on the arms, or at the very least have the ability (especially on the rear arms) to move the linkage connection point on the arm.

Having said all that.... the stiffer the swaybar the less grip that car will have at that end of the car. Or in your terms... a swaybar that moves 3mm with the same arm travel will have less grip than a swaybar that moves 7mm.

Martin.
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Old 03-13-2014, 07:47 AM   #126
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Based on a request from Zac Donathen, I added a section on bump steer to the LearnSetup.com app

Let me know what you think.

Martin.
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Old 03-13-2014, 09:57 AM   #127
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New user and racer. Was curious if anyone had a Scale Spec setup for a TC6.2 with a 25.5T motor (basically VTA setup) they'd like to share? Really trying to come up with a decent setup to learn on for medium to high grip carpet.
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Old 03-13-2014, 11:13 AM   #128
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Default Updated swaybar section

I updated the swaybar section to better answer the question...why you would run swaybars if they take away grip.

I also added a section on "swaybar adjustments"
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Old 03-13-2014, 07:07 PM   #129
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Hi Martin. I have been reading your traction rolling thread and this one. I also have the app on my droid and subbed to your web app.

Here is my senerio

I have a Factory Team TC4 (carbon Fiber chassis)

Below is my current setup that is a little roll happy. generally very fast just edge and when the rear breaks its breaks hard

This is on a very tight track 30x50 fast guys running 8.2 in 17.5 Stock TC Fastest I have been a 8.5

Basically the cars feels great but when it traction rolls it's very sudden
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Old 03-14-2014, 03:48 AM   #130
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Hi Martin,

Real quick question :-)
What is the negative to raising your Roll Center too high? Eg how do you know when you're gone too far?
Hope that makes sense.
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Old 03-14-2014, 06:42 AM   #131
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Martin,

I am setting up a TC4 for VTA and was reading through the manual and your learnsetup app last night. When it became time to set the wheelbase, the manual says "Shortening the rear will increase rear grip, while lengthening will decrease rear traction."

In your app you say "For example , if you adjust the wheelbase by moving both the front and rear axles forward relative to the chassis, you will be essentially putting more weight over the rear axle of the car, which will give the car more steering. If you move both axles toward the rear of the car you will get less steering."

What happens just by moving the rear forward? Also, I race at a track that has a very low grip carpet. The rear of my car is very unstable. What is a good starting point for a low (LOW!!!!) grip carpet setup? What areas of the setup would you be focusing on first to get the rear of the car stable?
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Old 03-14-2014, 12:08 PM   #132
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i understand weight transfer and over/understeer but rotation is a subject
were i am totaly lost. some cars just seem to rotate around tight hairpins
and carry more corner speed without any oversteer so how do i get good
rotation in the tight turns.
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Old 03-14-2014, 12:18 PM   #133
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Great thread Martin. Here goes my question. What would be the effect of raising or lowering
axle or diff height on a car?
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Old 03-16-2014, 02:56 PM   #134
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Martin,

I must say that I have learned more in the last few weeks of owning your app than in the previous many years of racing I have done. Using your app, I took a middle of the pack VTA car and made it dominant. I could do whatever I wanted to with this car and the cornering speed I had with it was crazy. The car was also consistent. On a track where I had been running 14-15.5second laps, I was running in the 12's. I spent the A Main just cruising around out front. The best part....where my car was previously squirmy on the straights, and LOOSE LOOSE LOOSE under power, this thing was hooked up and doesn't have a scratch on it. It was the most fun I have had wheeling a car in a long time! LearnSetup is an excellent tool and I have recommended it to many at my local track.
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Old 03-16-2014, 05:42 PM   #135
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Big Thanks to Everyone on here and Martin. My TC is bang on now and getting faster Went from 8.9 average to 8.5 Just some tweaks to remove the Traction rolling


Thanks
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