Now that guys are starting to use scales more often to set up their cars, what do most of you find are the percentages that you're seeing?
I found myself on the banks having a left to right of 58% left and 42% right with a front to rear of 52% front and and 48% rear. Does anyone have an opinion on this.

good question id like to know also. also what would you want for a flat track?

Now that guys are starting to use scales more often to set up their cars, what do most of you find are the percentages that you're seeing?
I found myself on the banks having a left to right of 58% left and 42% right with a front to rear of 52% front and and 48% rear. Does anyone have an opinion on this.

Well according to Most full size racing info books say to Start out with a baseline setup.

Since this info is for FULL size cars then I would experiment.

Flat to med bank dirt tracks - Left side 52%-54% Rear 52%-54%
Flat to med bank asphalt tracks - Left side 55%-58% Rear 51%-52%

Hmmm interesting numbers. Food for thought. I would have to bring my batteries back to get the front to be lower than the back.

http://www.hobbytalk.com/bbs1/showthread.php?t=142220

This link might help. This turned into a big discussion.

I know I am running like 66% left weight

http://www.hobbytalk.com/bbs1/showthread.php?t=142220

This link might help. This turned into a big discussion.

I checked out the link, good stuff. I'm just getting up to speed on using my scales more effectively. I really like that between heats, you can pop the car onto the scales and see if anything has changed, and often something does. It lets you be more precise, and precision is the name of the game in oval.

When using the scales don't get crazy with them. The best thing to do is use them to reset the car after maintance work or changes during practice that don't work out. After your best run, use the weights as a default #.

When using the scales don't get crazy with them. The best thing to do is use them to reset the car after maintance work or changes during practice that don't work out. After your best run, use the weights as a default #.

couldn't be further from the truth. we run asphalt where you se alot of tire wear. tire wear effects the weights. since I started using scales I put the car on them before every run and reset the cross weight.

I have to put mine on there every run to make sure the yahoo's I have on either side of me didn't mess with my car!! But yeah, we always throw them on to check our weights and make changes, then if it works you know where you were not where you are now!! And it also helps to see what the car does during the run, if it feels like it got tight does the scale show it or was it a tire or something.

I would forget about using full scale numbers as a reference - we have a much lower CG, a lot lower rear roll center, and a lot more rear weight than most full bodied oval cars. Since I started using 4-corner scales (about 3 years ago), my car has been much more consistent than it ever was before. I never have any problem putting the car right back to where it was before.

I would forget about using full scale numbers as a reference - we have a much lower CG, a lot lower rear roll center, and a lot more rear weight than most full bodied oval cars. Since I started using 4-corner scales (about 3 years ago), my car has been much more consistent than it ever was before. I never have any problem putting the car right back to where it was before.

You can use the full scale car numbers as a percentage reference and experiment. Everyone likes to setup there car differently to get the right feel for the track.

I agree with you. Using four scales is the best way to setup your
chassis. :thumbsup:

I am no expert but I worked on two of Floridas best short track racers teams for 20 years and picked up alot of set-up knowledge. The kind of numbers I see working well on my RC cars dont compare very well with what we ran on the big cars. Running foams on flat asphalt Im running more left side more rear and alot less diagonal then we ever ran on any big car.
I have to thank Davepull for talking me out of running the kind of diag I THOUGHT the little cars needed, made a huge differance! Thanks Dave!

My Question is how do determine the percentage for left side weight and front to rear weight transfer.

http://www.schoenfeldheaders.com/ChassisSetup.htm

here yah go tim

tHANKS dAVE

My Question is how do determine the percentage for left side weight and front to rear weight transfer.

Its is possiable to find actual total weight transfer on paper but is alot easyer to weight the vehicle at rest. (static weight)
As long as the process is repeated.

Static weight percentages are

Left front% = left front weight(oz) X Total car weight (oz)

Right front% = right front weight(oz) X Total car weight (oz)


Left rear% = left rear weight(oz) X Total car weight (oz)


Right rear% = right rear weight(oz) X Total car weight (oz)

Note: can be grams or oz or lbs.

You can add up the percentages for front, rear, leftside, crossweight. :thumbsup:

Rpm /

I have a small corner weight calculator program that works good if you have microsoft excel .

i have excel. could you send me a copy. n2racn@maine.rr.com
thank you
jeremy

Jeremy,

Check your email let me know if you have any problems.

I would also like a copy Thanks Oldtimer Kenneth.boem@sbcglobal.net

only problem is it is read only. cant change the #'s at all. if you can send it so i can change them it would be perfect.

thank you
jeremy

Jeremy:

I would love a copy of it as well.

email: amusicwiz1@aol.com

I have attached it in the zip file in the original post try that see if it works ok.

works perfectly. messed around with the numbers now cant wait to get the car on the scales and see where its at. thank you

jeremy

awhite: thanks for the file. can't wait (weight) to work with it this week.

bob

http://www.schoenfeldheaders.com/ChassisSetup.htm

here yah go tim

I've been playing around with a legends car this winter and I put it on my scales just for kicks.
left front: 8.66 oz
right front: 10.205 oz
left rear: 12.14 oz
right rear: 9.805 oz
What does this tell you about the chassis setup?

bst, with more static weight on the right front than on the left front, it tells me that by the time weight transfers off the left front onto the right front in the middle of the turn, your right front is relatively overloaded compared to your left front. Your left front will hardly be doing any work at all.

I don't know for sure, but on the Legends cars I guess you don't have all the possible adjustments you can make as on a 10L4 or something like that. It may be that you have the left rear tweaked down too much. If you can adjust that, take a little out.

If you need the left tweak to be able to put the power down off the turn, try re-arranging the components on your car to get more static weight on your left front. Last race I was at I had 10.2 on my left front and 7.4 on my right front. Granted that's not a Legends car, but you still want to have more weight on the left front than the right front.

I'm surprised no one has mentioned cross weight? Left/Right and Front/rear percentages are important, but crossweight is a measurement of wedge / tweak, that's what I look at the most. (Total of RF & LR divided by total car weight.

Thanks Guys, I reduced the amount of shims in my left front which gave me a LF of 9.24 oz and a RF of 9.49 oz . My crosswieght or wedge is 54.25 % I want to drive it first and then try removing one more shim. I'm guessing that this will make the LF heavier and reduce my wedge. Not sure what this will do for the car. Don

I'm surprised no one has mentioned cross weight? Left/Right and Front/rear percentages are important, but crossweight is a measurement of wedge / tweak, that's what I look at the most. (Total of RF & LR divided by total car weight.
Oh yeah, and another thing...
When you tweak your car (change wedge, whatever) the Left % and the Rear % won't change. The only way you can move those percentages is by shifting weight around on the car. I've learned this by setting up my real modified, and it all applies to RC as well.

Thanks Guys, I reduced the amount of shims in my left front which gave me a LF of 9.24 oz and a RF of 9.49 oz . My crosswieght or wedge is 54.25 % I want to drive it first and then try removing one more shim. I'm guessing that this will make the LF heavier and reduce my wedge. Not sure what this will do for the car. Don

Not familiar AT ALL with legends cars, but as mentioned earlier,
there are certain parameters that hold true for all oval cars...
One is, that you should not have your RF heavier than the LF.
When you vary significantly from these parameters, all you are
doing is adjusting for another issue.
In other words, if one says, "I need to run all this weight on the rf
or it won't handle".
There is another issue there being overlooked.
The problem is outside of the box.

The whole idea of making a car corner, is to have all four tires
working for you. If one is overloaded, it means one is not loaded enough.
So essentially, you are asking 3 men to do the work of 4... not good.
When you have a heavy RF, when cornering the LF becomes very light,
and is offering very little 'help'.

It appears that your legend cars are pretty much centered?
Meaning everything is nearly in the middle of the car?
And do rules restrict you from changing this?
Again, I have no idea what it looks like. :confused:

Can you shim the rear axle to move the LR closer to the car,
and the RR away from it?
This will give you more LR weight, and less RR weight.
Same with the front... can you do that? Shift the RF out?

Your problem is, there isn't enough left side weight to play with,
to get numbers that work well for oval..
What is going to happen is, as the LF weight comes closer to what
it should be, you'll have too much on the right rear, which means you
will be driving off that tire.. Which is not 'all' bad... you'll still be getting
weight off the RF. That's the one that can REALLY scrub speed...

The Legends cars are almost like driving a ladder on 4 wheels. Depending on the rules, there isn't much adjustment allowed. However, there are things that can be done to help "tweak" the chassis. Running wheel stagger is the biggest tuning option on these cars. I don't personally run a Legends car, but that is what the fast drivers do. Another tip is to manually tweak the chassis. This is achieved by loosening the chassis screws, twisting the chassis, and then tightening the chassis screws back. Now you have a purposely tweak chassis. Again I don't have a Legends but have seen the fast guys do this with their cars.

The other thing you can do if it is allowed is to add more weight to the left side of the chassis. Granted you never want a heavier car, but if you can get all 4 wheels working you will be faster than a car lifting the left front tire. Since these cars don't have any rear suspension, you have to think outside the box to tune them.

Other tuning aids are try to mount the body as far left as possible and to run a Coupe body. I've seen some drivers space the right rear waaaaay out to help the car turn, but that goes against the spirit of the rules. If you happen to run Legends at a track with loose rules, then you should take advantange of anything you can.

I like that, ladder w/ 4 wheels, that is your basic Legends car. I removed another shim from the front left. This changed my wieght to LF 10.46 oz, RF 8.28, LR 12.60, RR 10.55 and my wedge to 48.45%.
I didn't want to go below 50% on my wedge. I guess I can add 1/2 of a shim and rewieght it or different front springs. Thanks guys, don

I have a related (I think) question. I've been noticing after truing my front tires to the same size, my RF is wearing down pretty quick (BSR Black) and my LF (BSR White)looks like it hardly touches the ground? Doesn't really seem to be pushing, actually turns very well, just gets a little touchy if I really have to wrench the wheel hard. Feels like it's rolling over really hard in the turns. Don't have the exact #'s in front of me, but I'm pretty sure my LF is 9.5 oz. +/- and my RF is 7 oz. +/-. The LR is about 12.4 oz.

Should I be looking to get more weight on my LF? Will this help keep the LF on the ground through the turns? Or am I missing something else?

Thanks in advance for any input. Just put together my 4 scale setup & need to learn more about how to use it effectively.

Tom

Anyone???

I have a related (I think) question. I've been noticing after truing my front tires to the same size, my RF is wearing down pretty quick (BSR Black) and my LF (BSR White)looks like it hardly touches the ground? Doesn't really seem to be pushing, actually turns very well, just gets a little touchy if I really have to wrench the wheel hard. Feels like it's rolling over really hard in the turns. Don't have the exact #'s in front of me, but I'm pretty sure my LF is 9.5 oz. +/- and my RF is 7 oz. +/-. The LR is about 12.4 oz.

Should I be looking to get more weight on my LF? Will this help keep the LF on the ground through the turns? Or am I missing something else?

Thanks in advance for any input. Just put together my 4 scale setup & need to learn more about how to use it effectively.

Tom

What you should be looking at is not so much moving weight around but
looking at your tire temp.

Run your car on the track and bring up the temp in the tires.

Temp all four tires as soon as possible.
Now, move weight around until you get all the tire temp
the same. :thumbsup:

Next, weight your car on the scales and log info.

.....

I ran legends and won a few times. this is where i put everything to maximize my LF weight.
I cut the ear off the servo and mounted it under the ctr. plate w/servo tape and a tie wrap to insure no movement. the reciver was on top of the servo about a 1/4 in back.
the speedo was all the way back on the left rear corner. the transponder mount was in the center on the left outside plate as far forward as i could get it. Now I dont really recomend this to all but I ran my motor off the left side of the car, we had tight corners and good bite and a stiff RF and it worked well at this track. it will tend to tighten the off the corner. I also had 2 pieces of foam servo taped to the right side of the batt. area to force and keep the batt. to the left.

I ran legends and won a few times. this is where i put everything to maximize my LF weight.
I cut the ear off the servo and mounted it under the ctr. plate w/servo tape and a tie wrap to insure no movement. the reciver was on top of the servo about a 1/4 in back.
the speedo was all the way back on the left rear corner. the transponder mount was in the center on the left outside plate as far forward as i could get it. Now I dont really recomend this to all but I ran my motor off the left side of the car, we had tight corners and good bite and a stiff RF and it worked well at this track. it will tend to tighten the off the corner. I also had 2 pieces of foam servo taped to the right side of the batt. area to force and keep the batt. to the left.
I have the same set up except the servo. That's my next project. I like the tire temp idea too.

What you should be looking at is not so much moving weight around but
looking at your tire temp.

Run your car on the track and bring up the temp in the tires.

Temp all four tires as soon as possible.
Now, move weight around until you get all the tire temp
the same. :thumbsup:

Next, weight your car on the scales and log info.

I get what you're saying, but I don't have a temp gun. I know the RF is going to be the warmest. As I said it's wearing noticably faster than the LF, which doesn't appear to be touching the ground (or at least not with much force) all the time.

I did move some weight around, but I don't have much to play with. Solid chassis, GTX ESC, Spektrum reciever. Got a little more on the LF, but not much. Can't really do anything else for static weight, the reciever & ESC are on the LF edge of the chassis in front of the battery (which I moved forward 1 slot).

Am I barking up the wrong tree here? Should I perhaps try a softer RF tire & a change in spring rate? Maybe it's really pushing even though I think it turns pretty well?

Thanks for the input! Think I'll try to get ahold of a temp gun & play with that a little too!

I get what you're saying, but I don't have a temp gun. I know the RF is going to be the warmest. As I said it's wearing noticably faster than the LF, which doesn't appear to be touching the ground (or at least not with much force) all the time.

I did move some weight around, but I don't have much to play with. Solid chassis, GTX ESC, Spektrum reciever. Got a little more on the LF, but not much. Can't really do anything else for static weight, the reciever & ESC are on the LF edge of the chassis in front of the battery (which I moved forward 1 slot).

Am I barking up the wrong tree here? Should I perhaps try a softer RF tire & a change in spring rate? Maybe it's really pushing even though I think it turns pretty well?

Thanks for the input! Think I'll try to get ahold of a temp gun & play with that a little too!

I have a temp gun you can use, I will bring it to the track next time I race. If you like it, I have somone who sells them CHEAP. See Ya at the track. :wave:

Thanks Charles! I talked to Freddie he says he has them cheap, so I will probably "support my local hobby shop". Maybe 'll have this thing together for next time you're racing. Should be an interesting race! See you then!

Going back to the servo setup and position. Im not sure what servos you guys use,but for max front end weight and toughness I always ran futaba 148 there bullet proof and the weight helped a lot. As far as temping the tires yes it works but I think its kind of obvious that the RF is going to be the warmer tire. the only thiing that is going to make it cooler is getting weight off. With a legend you can only go so far. Another point would be are you creating a push or a loose condtion by having too much steering.This will also build heat up in the RF. remember you should only have enough steering to get around the corner. If your able to turn your car around to the left in less than a ten foot radius you have too much steering in it. The track I run at (r/c maddness-enfield) my tires turn to the left less than a 1/4 of an inch.