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Old 04-09-2014, 05:15 AM   #301
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Originally Posted by Martin Crisp View Post
After looking at your setup I would suggest trying each of the following

Try this first.
a) Inboard upper link spacers in the rear : go from 2mm to 3mm
b) Make the rear upper link longer - full length possible
will this reduce rar traction?

Then try
c) lowering the front ride height from 5.6mm to 5mm and leave the rear at 5.6mm this will give the car "rake" which creates more downforce and also generates more steering.i had to settle for 5.6 as the chassis was scraping,so im up to 5.8 ft and 6 rear its a very bumpy technical but flowing track

Then Try
d) going to 2.4 springs front and rear down from 2.7, to allow for more weight longitudinal weight transfer. It should give more off power steering, but perhaps less on powersteering, but diff oil suggestions below will help compensate for the on power push.

Then try
e) laying down the rear shocks one hole. This allows more lateral roll in the rear which tends to free up a car on entry and middle. done this


Then experiment with some diff oil changes. These may bring the off power push back, but try it anyway, as they will give you some good on power steering, and maybe we can deal with the push in other ways.
c) Change your rear diff oil from 350 cst to 2k cst
d) change your front diff oil from 450 cst to 500k. I think you should also try 1m in the front as well. It may create too much of a push off power, but it will give you more on power steering.
thanks martin always appreciated,the diff oils make no sense,i have 2000k in the rear and a spool up front,i usualy run with 3000k but thats on a larger/faster track,the car was perfect in every way apart from the push ,so just looking to address that,hence the 2nd set up which is the one ill start with this weekend,i was also down on speed due to having to use a different motor that i didnt gear right,ive got the motor i like the most back in
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Old 04-09-2014, 08:26 AM   #302
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Originally Posted by chasingthepack View Post
thanks martin always appreciated,the diff oils make no sense,i have 2000k in the rear and a spool up front,i usualy run with 3000k but thats on a larger/faster track,the car was perfect in every way apart from the push ,so just looking to address that,hence the 2nd set up which is the one ill start with this weekend,i was also down on speed due to having to use a different motor that i didnt gear right,ive got the motor i like the most back in

re: diff oil:
my mistake - I read the shock oil numbers thinking they were the diff numbers - D'oh. Stupid brain
You might want to try 1k in the rear then to help reduce the resistance to rotation off power. You will loose some on power steering with this change, but not too much if since you run a spool up front. Another approach would be to run a diff up fron with 1m, and 1k in the rear diff. This will allow the car to turn in much better than a spool and 2k in the rear.

re: the longer rear upper link giving more steering. Yes it will because it reduces the camber gain.
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Old 04-09-2014, 08:47 AM   #303
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Originally Posted by Bgilli26 View Post
Hi there guys, I I am wanting to add some anti squat to my 6.1wc to gain some more traction under acceleration out of the corner. Can anyone explain how to add it to the Tc6.1 wc? Thank you guys very much for all the info and help!
Sorry - I don't know the 6.1wc chassis to tell you. I am sure someone on here would know. Or ping my fellow countryman Kevin Hebert.

Quote:
Originally Posted by energydrink View Post
Hi Martin .

If I took two pistons , which had equal area of piston holes , but different amount of holes , would they have the same dampening, but more pack for the one with more holes ? For instance , 3 hole 1.1 and 2 hole 1.5 , both have nearly equal area ; so would they have the same dampening, but the 3 hole has more pack ?
yes the 3 hole would for sure have more pack (ie. more high speed dampening). Both would have similar low speed dampening.

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Originally Posted by I)arkness View Post
not sure what your knowledge is on 12scale is but if you are able to answer my question that would be great, otherwise will keep learning.

whenever i run my crc xti transverse with close to 0 toe in on the front end i find that car to have a inconsistent feel and snap oversteer, but when i go back to about 1 to 2 degrees toe in, it settles this down and makes the driving much more consistent and im able to place the car in the turn where i want it. however then i start to get understeer mid corner.

would there be a way to change setup to help run less toe in?

cheers.
brad
Hey Brad


I only ran 1/12th scale about 5 times in my life, so there are for sure more qualified people than me to answer. But front toe principles are the same for any car. With the 0 toe setup your car will have the tires more close to parallel when in the middle of the trurn. This produces less slip angle on the inside tire, which will produce more grip. The ackerman settings on your car (which can also be called Dynamic Toe) also affect this. If your ackerman is setup to add a lot of dynamic toe, this will produce a very large slip angle on the inside tire reducing grip.

So it is not surprising to me that your toe out setting feels more stable in the middle of the corner as it will produce less mid corner steering. The toe out will make the car turn in a little more sharply however.


Quote:
Originally Posted by Codfather View Post
Hi Martin,

Sorry if this has been asked before, I haven't had time to go through this whole thread, feel free to point to a previous post. I love all your setup tips and fixes, but what steps do you take during the build to ensure proper setup? For instance, on a TC
-How closely do you look at battery weights and engine weights to make sure things are balanced side to side or front to back?
-Do you move the receiver and ESC around also?
-Do you shim the motor off the motor mount, move the battery inboard or outboard?
-Do you shift the battery forward or backward?
-If you add weight, where do you put it? and what are you trying to accomplish?

These are the only items that come to mind right now, I'm sure you have many more insights. Bought your android app some time ago, love it.
There is a lot of things I think about when building a car in terms of layout of weight, building a square chassis, and ensuring there is no unwanted binding of moving parts.

In tems of weight the best thing to do is to have the weight as close to the center point of the car. So the motor should not have any shims moving it outward from the motor mount. The battery should be as close to the center line as possible without hitting the belt. Any weight you add, try to do that below the center belt in the middle of the car if possible. Adding weight in front of the servo and/or battery is not desireable, not is adding weight behind the motor or battery. Having said that we often don't really have a choice depending on what the min weight requirements are. I try to have the esc and receive as close to the center line as possible, but I would move the receive out a little bit to make room for placing weights along the center line because the weights are typically heavier.

I make sure the left / right balance of the car is even. - very very important.

I try to make the forward / rearward weight balance be even as well.

I plan to build a video about this very topic for the LearnSetup.com app.

Quote:
Originally Posted by Nathan Wilson View Post
Hi martin, what is the ebst way to achieve more mid corner steering without affecting the turn in to much

Thanks
Reduce your ackerman is a great way to gain mid corner but not change turn-in.

Also raising your front roll center by taking out about between 0.5 to 2mm of spacers from the front inboard upper camber link will give you more mid corner steering, but does affect the turn in a little.
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Old 04-09-2014, 03:29 PM   #304
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Originally Posted by Martin Crisp View Post
re: diff oil:
my mistake - I read the shock oil numbers thinking they were the diff numbers - D'oh. Stupid brain
You might want to try 1k in the rear then to help reduce the resistance to rotation off power. You will loose some on power steering with this change, but not too much if since you run a spool up front. Another approach would be to run a diff up fron with 1m, and 1k in the rear diff. This will allow the car to turn in much better than a spool and 2k in the rear.

re: the longer rear upper link giving more steering. Yes it will because it reduces the camber gain.
cheers martin,so heres another set up taking on board what you said.and with my own theories.copared with set up 1 whats your thinking now or do you think ive taken it too far,i guess only track time will tell,practice saturday and see,i cant really go softer or lower due to the bumps,or stiffer on the oil,it would make the car unstable in the sweeper
http://forum.teamxray.com/xform/inde...&setup=t4_2014

heres the track,its was drizzling from 2 mins in ,where the car was pushing was from the end of the sweeper turn right and on entry to the left 180 hairpin back towards the middle of the track,poor vid as my son forgot the first 3 mins,i had already got into 1st by the start of the vid

https://www.youtube.com/watch?v=Y2-LCdnSerA
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Old 04-09-2014, 04:49 PM   #305
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If you have a car that feels good and doesn't really need anything in particular , what changes would you make to get more corner speed / faster lap times ?
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Old 04-09-2014, 06:42 PM   #306
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Originally Posted by chasingthepack View Post
cheers martin,so heres another set up taking on board what you said.and with my own theories.copared with set up 1 whats your thinking now or do you think ive taken it too far,i guess only track time will tell,practice saturday and see,i cant really go softer or lower due to the bumps,or stiffer on the oil,it would make the car unstable in the sweeper
http://forum.teamxray.com/xform/inde...&setup=t4_2014

heres the track,its was drizzling from 2 mins in ,where the car was pushing was from the end of the sweeper turn right and on entry to the left 180 hairpin back towards the middle of the track,poor vid as my son forgot the first 3 mins,i had already got into 1st by the start of the vid

https://www.youtube.com/watch?v=Y2-LCdnSerA
I woudl lower the front ride height to 5.6 if you can.

It looks like you removed 1mm spacers from the inboard upper links in the rear. I really think you should have added 1mm making it 3mm

Quote:
Originally Posted by energydrink View Post
If you have a car that feels good and doesn't really need anything in particular , what changes would you make to get more corner speed / faster lap times ?
As you can no doubt appreciate, this is a hard question to answer, but there are a few general guidelines I would recommend.

Make more Loose:
Making the car a little more loose without being too loose that makes it to hard to drive consistently is typically a good thing to try. A lot of drivers that ask me to work on their cars feel the balance is good to them, but when I driver their car, it is often too tight and as such scrubbing too much speed in the corners.

Increase Lateral Grip:
To increase lateral grip you need to try and optimize three things.

One is to optimize the contact patch on the outside tires throughout the entire corner. This is achieved through optimizing the static camber and the camber gain through optimizing the upper links and caster.

The second thing to optimize the slip angle of the front and rear tires. Realistically the main thing to focus on here is the ackerman. If you run less ackerman (dynamic toe) then you will end up with more lateral grip in the front of your car especially noticed in the middle of the corner.

The third is keeping the vertical load on the inside and outside tires as equal as possible. This is mainly controlled through roll center. Basically the higher the roll center the more evenly distributed the vertical load will be on the inside and outside tire, which leads to more lateral grip. This is the easiest change to make to give more lateral grip. Swaybars actually take away lateral grip because they increase the difference in vertical load between the inside and outside tires. Swaybars really are there to help make handling more consistent, but they take away lateral grip.
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Old 04-10-2014, 06:06 AM   #307
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I'm going back to droop over ride height again and this is pertaining to a chassis that has tweak and is corrected using a hudy tweak station. Let's say everything is set using hudy's method of downstop gauges. I have removed tweak but now need to adjust my droop using ohr method with tires and suspension still attached. My problem is that a corrected tweak chassis will have a noticeable twist to it if you look at it from the front or rear.

Ill use the front as reference
The downstop screws is at a different height since the chassis is twisted slightly. So when adjusting droop ohr do I slide a gauge down center of the chassis end or on the corner of each side to measure?

Thank you.
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Old 04-10-2014, 05:28 PM   #308
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Originally Posted by Martin Crisp View Post
I would lower the front ride height to 5.6 if you can.

It looks like you removed 1mm spacers from the inboard upper links in the rear. I really think you should have added 1mm making it 3mm


my mistake it should have been 3mm on the sheet,force of habit with 1mm,lol ill have a go at 5.6 and see if the chassis rubs,im experimenting with the ackerman removing 1mm at a time,with the 3mm shim on the rear should i change the camber or leave as is? ill be running a new set of tyres in practice so that'll give me the correct contact patch,cheers
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Old 04-11-2014, 03:26 PM   #309
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Originally Posted by b20btec View Post
I'm going back to droop over ride height again and this is pertaining to a chassis that has tweak and is corrected using a hudy tweak station. Let's say everything is set using hudy's method of downstop gauges. I have removed tweak but now need to adjust my droop using ohr method with tires and suspension still attached. My problem is that a corrected tweak chassis will have a noticeable twist to it if you look at it from the front or rear.

Ill use the front as reference
The downstop screws is at a different height since the chassis is twisted slightly. So when adjusting droop ohr do I slide a gauge down center of the chassis end or on the corner of each side to measure?

Thank you.

Hi,

Just so I understand correctly, what do you mean you "removed the tweak"? Do you physically straighten out the chassis or did you just leave it twisted and adjusted things like droop and ride height to compensate? It sounds like it is the later, then you need to go back and straighten out the physical chassis. If you are not sure how to do this. The basic process is to undo the upper deck and lower chassis screws, and shock tower screws about a full turn....give the car a little twist back and forth to get rid of any binding. Then do up the bottom chassis screws....put the chassis on a flast surface and while pushing down on the front and rear shock towers, tighten the upper deck screws again. Then tighten the shock tower screws.




Quote:
Originally Posted by chasingthepack View Post
my mistake it should have been 3mm on the sheet,force of habit with 1mm,lol ill have a go at 5.6 and see if the chassis rubs,im experimenting with the ackerman removing 1mm at a time,with the 3mm shim on the rear should i change the camber or leave as is? ill be running a new set of tyres in practice so that'll give me the correct contact patch,cheers
Leave camber where it is to start, but you might need to adjust as you learn more about the track of course.

M
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Old 04-12-2014, 07:28 PM   #310
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Hi Martin,

Enjoying reading the ipad workbench app and started to read this thread.

In the beginning, I was struggling with translating some terminology and trying to picture/visualise the location of the item on a car.
E.g, outboard front link, inboard front link, arm mounts
go from hole 1 in the inboard front upper link to hole 3 (makes the link longer)
go from 2mm shims on the outboard front upper link to 1mm shims
go from 1mm shims on the inboard front upper link to 2mm shims
1mm shims under the arm mounts

Is there some diagram that may help to show the various adjustments points?

Can you explain why and how bump steer adjustments impact the handling.

Many thanks.
Fred
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Last edited by Fredp1; 04-13-2014 at 04:28 AM. Reason: Added under arm mounts
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Old 04-13-2014, 12:06 AM   #311
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Today I got a chance to play with the rear upper links. This after having a loose rear end car for the last half of each heat. So I started with 3mm shim on inner upper link and I think it was 3mm as well on outer hub. I also had shocks in middle and switched to a lower hole on shock tower with same results. After race was over I threw on a 4mm on inner link with tires still being dirty from last race. The car seemed to hold better and not break loose at least from the few laps I got in before track shutdown.
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Old 04-13-2014, 10:11 PM   #312
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Originally Posted by Martin Crisp View Post
Hi,

Just so I understand correctly, what do you mean you "removed the tweak"? Do you physically straighten out the chassis or did you just leave it twisted and adjusted things like droop and ride height to compensate? It sounds like it is the later, then you need to go back and straighten out the physical chassis. If you are not sure how to do this. The basic process is to undo the upper deck and lower chassis screws, and shock tower screws about a full turn....give the car a little twist back and forth to get rid of any binding. Then do up the bottom chassis screws....put the chassis on a flast surface and while pushing down on the front and rear shock towers, tighten the upper deck screws again. Then tighten the shock tower screws.

M
I'd like to suggest removing the belt pulleys as well if its a belt driven car. This will remove any belt tension from the equation when removing tweak if it involves loosening the lower deck screws.
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Old 04-14-2014, 07:21 AM   #313
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Hi martin could i please have your advice on a scenario. Outdoor on asphalt, lets say your car is handling well and is fast on track when temps are low. what typically would you change as the temps increase to keep the pace. my car tends to go slower as the temperature increases.

Thanks
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Old 04-14-2014, 11:39 AM   #314
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Originally Posted by Nathan Wilson View Post
Hi martin could i please have your advice on a scenario. Outdoor on asphalt, lets say your car is handling well and is fast on track when temps are low. what typically would you change as the temps increase to keep the pace. my car tends to go slower as the temperature increases.

Thanks
i had the same problem,when the track temp was under 25c my car was perfect,but when it reached 38c the push was worse
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Old 04-15-2014, 10:49 AM   #315
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Originally Posted by Fredp1 View Post
Hi Martin,

Enjoying reading the ipad workbench app and started to read this thread.

In the beginning, I was struggling with translating some terminology and trying to picture/visualise the location of the item on a car.
E.g, outboard front link, inboard front link, arm mounts
go from hole 1 in the inboard front upper link to hole 3 (makes the link longer)
go from 2mm shims on the outboard front upper link to 1mm shims
go from 1mm shims on the inboard front upper link to 2mm shims
1mm shims under the arm mounts

Is there some diagram that may help to show the various adjustments points?

Can you explain why and how bump steer adjustments impact the handling.

Many thanks.
Fred
Good point. I should add a diagram in the LearnSetup.com app that identifies some common terminology related to physical locations on the car.

Quote:
Originally Posted by Josh-n-ya View Post
Today I got a chance to play with the rear upper links. This after having a loose rear end car for the last half of each heat. So I started with 3mm shim on inner upper link and I think it was 3mm as well on outer hub. I also had shocks in middle and switched to a lower hole on shock tower with same results. After race was over I threw on a 4mm on inner link with tires still being dirty from last race. The car seemed to hold better and not break loose at least from the few laps I got in before track shutdown.
Normally when adding more spacers to the inboard upper link in the rear, you will get more steering. Since the tires were dirty, perhaps the balance of the car was not where it would have been if you had cleaned the tires and added the tire traction compound again. You might want to experiment again but ensuring you have equally prepared tires and track.

Quote:
Originally Posted by Nathan Wilson View Post
Hi martin could i please have your advice on a scenario. Outdoor on asphalt, lets say your car is handling well and is fast on track when temps are low. what typically would you change as the temps increase to keep the pace. my car tends to go slower as the temperature increases.

Thanks
As track temps come up the tires overheat and you loose grip. Of course you can go to a tire compound better suited for high temps which will have less overall grip, but won't change as much during the run.

Another thing to think about is how can you reduce the sliding and tire slip angle and still maintain the handling/balance you like.

Typically raising the roll center will reduce sliding

Reducing front toe out can reduce the front tire slip angles as well as reducing your ackerman. Both of these changes will affect your balance however so you would need to experiment. less ackerman gives more mid corner steering. less static toe will give more mid corner steering and less initial turn-in.

In the rear, if you have more than 3 degrees toe-in reducing to 3.0, 2.5 and 2.0 should be considered, but at some point it will make the car too loose and cause more sliding of the rear tires making things worse.

From a shock setup point of view you will want to reduce the tire bounce as much as possible. This can be done by going to larger piston holes, which decrease the high speed dampening. Also you could consider balancing the wheels.

Quote:
Originally Posted by chasingthepack View Post
i had the same problem,when the track temp was under 25c my car was perfect,but when it reached 38c the push was worse
yes...makes perfect sense as the 38 tire has less grip than a 25 tire. However I would imagine the 38 stayed more consistent.
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