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Old 12-22-2014, 01:01 PM   #541
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Originally Posted by Martin Crisp View Post
Originally Posted by hanulec View Post
soft chassis and high grip just don't work. low spring rate is key when grip comes up.

soft chassis + hard springs is great in low bite.

my car almost drives like it is broken until grip comes up. dialing yourself in under low grip basically never works (unless it is a low grip event -- like 1/12th worlds). don't be afraid to try things --- and ask (more) people for help...



Hanulec and I agree re: high grip. Always a stiffer chassis and software springs will help prevent traction rolling. The softer springs will allow the car to roll into the carpet more keeping the cg lower which helps prevent traction rolling. Also it is likely your chassis will rub against the carpet, which will take away lateral grip...also helping prevent traction rolling.

As for low grip, my point of view is different than Hanulec. I would run a softer spring to enable more weight transfer forward and back so that I can control the balance with throttle and break when I need to. Also I would run a high roll center to prevent maximize lateral grip by minimizing the loss of downward force on the inside tires while cornering.

As for medium grip tracks, this is when I might start to either go up in the spring rate slightly if the chassis is rubbing, or lower the roll center if i start to traction roll.

Cheers and merry xmas

Martin.
Thanks Martin.
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Old 12-25-2014, 02:30 PM   #542
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Will learn setup work with out a internet connection once downloaded ?
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Old 12-26-2014, 04:44 PM   #543
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I could use a little help with my setup...
TC6.1W.... lowered shock towers and WC top plate
I am have a really hard time getting the rear of the car planted... it really wants to over rotate from mid comer to exit.
thanks in advance

edit.... 4* caster & -3* toe in on each rear (-6 total?)
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Old 01-01-2015, 08:28 AM   #544
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Hi Martin,

Glad to see you've set up this thread. I have had a copy of your original book (M-Power setup) by my side for about 10 years now as I dabble with touring chassis off and on. I also purchased your Android phone app though haven't figured out how to transfer it to my new phone. I have recommended the XXX-Main version of the book to any and all when I see folks "looking for the magic set up for (insert chassis name)" online and at my home track. Teach a man to fish...

I have a couple questions that are likely related but that I do not see addressed in your book(s) and a third that isn't related. Purchased a lightly used TC6.1 Worlds chassis and have been going through it (replacing bearings and a couple broken parts) in preparation to run VTA with it. I will put Kevin Hebert's medium traction carpet setup on it for a baseline before I tweak it to my driving style and our track/carpet conditions.

1) What effect on handling does moving the inner hinge pin mounts in or out have? The TC6 (and, I think, the TC5 did also) has standard and "offset" inner pin mounts, the offset mounts move the pins (and, hence, the arms, knuckles, axles ans wheels) out 2mm on each side. The assembly instructions indicate that offset mounts fore and aft for the front pins and standard fore/offset aft to set up most of the rear toe needed. Guessing you want to take advantage of the most track width you can and remain within the rules, but what are the effects?

2) a related (possibly) question...when disassembling the chassis I noticed that on the front suspension these hinge pin mounts were installed offset at the fore and standard at the aft end of the inner pins. They were then shimmed out some amount. The net effect was that these inboard pins were "toed out" quite noticeably. I don't believe I'd ever seen anything like this and thought it might be something goofy until I looked at Hebert's set up and it appears he does something similar though it appears he is doing it all with shims. Why? It seems like it would create a bump-steer situation and maybe some amount of dynamic caster change though I can't entirely visualize this. What's going on here?

3) Entirely unrelated, the chassis allows for some amount of adjusting the differential height relative to the chassis plane and the suspension pieces. What is the effect of raising and lowering these? Is it merely the incremental change in CG height?

Many thanks Martin, both for answers to these questions and the MANY answers you've provided over the years in the books!

Scott
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Old 01-01-2015, 02:10 PM   #545
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Originally Posted by Friulimotosport View Post
Will learn setup work with out a internet connection once downloaded ?
No, it's an online web page that you can browse.
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Old 01-02-2015, 07:36 AM   #546
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Originally Posted by 1AGOFST View Post
Hi Martin, Great Thread and I love the Website!!! I have what is hopefully a simple question:

On XRAY's Setup website, most, if not all setups of the drivers posted are for Mod racing. I live very close to Kissimmee where the electric Touring Worlds were held. I only run 17.5 class, so what difference in setup could I expect so I can translate the mod setups into a 17.5 setup? I have a T4 '15. Hope that makes sense.

For me, I always ran the same setups for 17.5 as I did for modified. Having said that because you could likely handle a slightly more loose car with 17.5, you might want to try a little less rear toe in (i.e. 0.5 degrees less). Other than that, keep everything the same.

Thanks again!
Mike
Quote:
Originally Posted by thecaptain View Post
Martin what else would you do to take traction out of the car besides a stiff chassis and springs? Any specific tuning advice?
Actually stiffer springs will make traction rolling worse as per some of my previous posts. Lower roll centers, and reduced "up travel/droop" tend to be a good idea as well. The key idea with softer springs, reduced droop, and lower roll centers is to keep the center of gravity (CG) as close as possible to the ground.

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Originally Posted by rick oxley View Post
most setup talk seems about the amount of weight transfer but little mention of the speed the weight transfers i find this has a great impact on how the car handels(weight+speed= momenterm) could we have your thoughts on this please
martin.
Speed of weight transfer is very critical actually. This is a function of how smooth you are as a driver, but also how you setup your shocks. If the weight transfer happens too fast, then you can loose initial lateral grip. . Once the tires loose grip you have to request less of them than their maximum to regain the grip. This means you not only loose initial lateral grip, but you need to go below the limits of the tire again before you gain maximum grip.
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Old 01-02-2015, 07:43 AM   #547
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Quote:
Originally Posted by Friulimotosport View Post
Will learn setup work with out a internet connection once downloaded ?
no it is a web based application so you do need an internet connection.

Quote:
Originally Posted by BulletMan View Post
I could use a little help with my setup...
TC6.1W.... lowered shock towers and WC top plate
I am have a really hard time getting the rear of the car planted... it really wants to over rotate from mid comer to exit.
thanks in advance

edit.... 4* caster & -3* toe in on each rear (-6 total?)
I find it hard to understand the associated setup sheet upon just a quick glance. Having said two things jump out at me if I interpret the setup sheet correctly.

1) your rear roll center is too low. I think it says your camber link is using hole 1 on the shock tower, which is the top most inner hole. Use the bottom most inner hole. i.e. use hole 5 on the shock tower. If that takes away too much steering then try hole 3.
2) your rear shocks are laid down too much. You are currently using hole 3 in the shock tower for the upper shock mount. Try hole 5.

Cheers.
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Old 01-02-2015, 09:16 AM   #548
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Originally Posted by Scottrik View Post
Hi Martin,

Glad to see you've set up this thread. I have had a copy of your original book (M-Power setup) by my side for about 10 years now as I dabble with touring chassis off and on. I also purchased your Android phone app though haven't figured out how to transfer it to my new phone. I have recommended the XXX-Main version of the book to any and all when I see folks "looking for the magic set up for (insert chassis name)" online and at my home track. Teach a man to fish...
So happy to see people getting value and hopefully enjoying the hobby more

Quote:
I have a couple questions that are likely related but that I do not see addressed in your book(s) and a third that isn't related. Purchased a lightly used TC6.1 Worlds chassis and have been going through it (replacing bearings and a couple broken parts) in preparation to run VTA with it. I will put Kevin Hebert's medium traction carpet setup on it for a baseline before I tweak it to my driving style and our track/carpet conditions.

1) What effect on handling does moving the inner hinge pin mounts in or out have? The TC6 (and, I think, the TC5 did also) has standard and "offset" inner pin mounts, the offset mounts move the pins (and, hence, the arms, knuckles, axles ans wheels) out 2mm on each side. The assembly instructions indicate that offset mounts fore and aft for the front pins and standard fore/offset aft to set up most of the rear toe needed. Guessing you want to take advantage of the most track width you can and remain within the rules, but what are the effects?
Good question, that does not have just one answer because of a number of variables, so I will make some assumptions here. I am going to assume that your lower suspension arm has the inboard hinge pin lower than the outboard hinge pin. (note: if it is the other way around then this creates a completely different scenario).

As you start to move the lower arm inboard hinge pin outwards (equal amounts fore and aft) from the center line of the chassis, you are lowering the static roll center, and you are also keeping the roll center lower with as the car leans. I assume you will lengthen the upper link as well to keep the camber the same as before.

So basically you lower the roll center and it keeps the roll center lower longer as the car rolls. Good for high grip tracks basically. Not good for low grip tracks


Quote:

2) a related (possibly) question...when disassembling the chassis I noticed that on the front suspension these hinge pin mounts were installed offset at the fore and standard at the aft end of the inner pins. They were then shimmed out some amount. The net effect was that these inboard pins were "toed out" quite noticeably. I don't believe I'd ever seen anything like this and thought it might be something goofy until I looked at Hebert's set up and it appears he does something similar though it appears he is doing it all with shims. Why? It seems like it would create a bump-steer situation and maybe some amount of dynamic caster change though I can't entirely visualize this. What's going on here?
This is referred to as sweep in the front of your car. It apparently adds more steering by having more sweep.

Quote:
3) Entirely unrelated, the chassis allows for some amount of adjusting the differential height relative to the chassis plane and the suspension pieces. What is the effect of raising and lowering these? Is it merely the incremental change in CG height?
The theory is this...

The higher the diff the at the rear of the car, the less the fron tend will lift under acceleration because of the increased leverage the rear diff has.

The higher the diff in the front of the car, the more the car will squat under acceleration because the front diff has more leverage.


...in reality, from my testing I could not really feel or see much if any difference....so I always run in the lower positions just to keep the cg lower.



Quote:
Many thanks Martin, both for answers to these questions and the MANY answers you've provided over the years in the books!
Thank you!! Cheers! and happy new year!
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Old 01-02-2015, 11:27 AM   #549
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Hey Martin I have a question regarding swaybars. I understand that a thicker sway bar is going to "take away" traction from the end of the car you put it on. So in theory you want thicker sway bars on the car for a higher traction level to take away traction from the car. Now also in theory you want a stiffer spring on the car to take away traction but In reality you want a softer spring for that. Since a sway bar is a flat spring do you want a stiffer or harder sway bar to take away traction at a high level of traction?
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Old 01-03-2015, 11:12 AM   #550
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Originally Posted by thecaptain View Post
Hey Martin I have a question regarding swaybars. I understand that a thicker sway bar is going to "take away" traction from the end of the car you put it on. So in theory you want thicker sway bars on the car for a higher traction level to take away traction from the car. Now also in theory you want a stiffer spring on the car to take away traction but In reality you want a softer spring for that. Since a sway bar is a flat spring do you want a stiffer or harder sway bar to take away traction at a high level of traction?
There ware two ways to reduce traction rolling. One is to of course reduce traction, the other is to make the car roll into the carpet more and keep a lower center of gravity. The reason why stiff springs make traction rolling more likely is because they don't allow the car to roll into the carpet as easily and keep the cg higher. The same thing happens with swaybars. The siffer the swaybar the less the car rolls and it tends to catapult the car over the outside edge of the outside tires.
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Old 01-04-2015, 12:57 PM   #551
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Originally Posted by Martin Crisp View Post
There ware two ways to reduce traction rolling. One is to of course reduce traction, the other is to make the car roll into the carpet more and keep a lower center of gravity. The reason why stiff springs make traction rolling more likely is because they don't allow the car to roll into the carpet as easily and keep the cg higher. The same thing happens with swaybars. The siffer the swaybar the less the car rolls and it tends to catapult the car over the outside edge of the outside tires.
Again about traction roll:

- If I have traction roll problem, should I lower ride height, or should I raise ride hight...?
- Second one: If I get rid of traction roll problem otherwise, but touching (or thinking...) a road disk just a little causes traction roll. Same rule should work as well, but is there any other tricks for that?

And yes, I know I should't touch road disks! But if You do it one time per round, and it causes everytime traction roll so... )
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Old 01-04-2015, 03:58 PM   #552
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Originally Posted by Martin Crisp View Post
There ware two ways to reduce traction rolling. One is to of course reduce traction, the other is to make the car roll into the carpet more and keep a lower center of gravity. The reason why stiff springs make traction rolling more likely is because they don't allow the car to roll into the carpet as easily and keep the cg higher. The same thing happens with swaybars. The siffer the swaybar the less the car rolls and it tends to catapult the car over the outside edge of the outside tires.
Thank you Martin! Looking forward to using this knowledge at upcoming races.
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Old 01-04-2015, 09:01 PM   #553
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It appears your app no longer works on ios8, or am I the only having this issue?
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Old 01-05-2015, 04:32 PM   #554
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Originally Posted by markova View Post
Again about traction roll:

- If I have traction roll problem, should I lower ride height, or should I raise ride hight...?
- Second one: If I get rid of traction roll problem otherwise, but touching (or thinking...) a road disk just a little causes traction roll. Same rule should work as well, but is there any other tricks for that?

And yes, I know I should't touch road disks! But if You do it one time per round, and it causes everytime traction roll so... )
LOL!!

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It appears your app no longer works on ios8, or am I the only having this issue?
Hi, yes this is true and was discussed in this forum at some length

The setupworkbench.com site indicates that the app does not work on IOS8 and that development on the setupworkbench app has stopped because I lost the source code and frankly tired of dealing with Apple. Instead I now offer a web based application that runs on any device called learnsetup.com. I designed it so it looks and acts like a an app running on your mobile devices, but you can also run it on your laptops, desktops, tablets, running unix, osx, windows or whatever your flavour is. This new app was launched about a year ago. One important benefit of this new app is that you can see setups that others share with you including pro setups. You can of course always save your own setups and keep the private if you prefer. This new app is an annual subscription of $10 per year, which is inexpensive and from what I hear from everyone, provides great value.

To learn more about this new app go to http://www.learnsetup.com

Cheers and make it a great day!

Martin.
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Old 01-26-2015, 08:53 AM   #555
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Hello! A few questions:

"-ve" means negative camber, correct? Sometimes you refer to "more camber", do you mean "more negative camber"? e.g. "This can produce the opposite affect, if you had more camber than optimal camber, and thus by reducing the negative camber you are actually increasing the contact patch of the tire." I am not quite following that statement.

Regarding roll center, do I have this right: moving inboard/upper link position down moves RC up, and moving inboard/upper link position out (away from chassis) also moves RC up?
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