shinnster

Just got my longacre racing scales. Going to try and corner balance my car this weekend.
I didn't get the leveling plates, just the scales.
My question is how level do all the scales need to be? If it off by less the a few milimeters will it be considerably off?
I'm setting up my car for mostly spirited street driving and around 5 - 7 track events a year, so i'm not trying squeez absolute perfection from the corner balance, Just withing a good spec..
Running Ohlins coilovers.
I'm trying to do this to learn how to do it so any advice would be helpful.

Bullet01

iTrader: (7)

Well basically, you'll get a somewhat ok corner balance. But without the leveling plates your corner balance won't be 100% accurate. Find as level ground as possible to help.

Without the leveling plate your scales will be good for a 100% car scale but not 100% corner weighting. Plus with the new leveling pads they have out there, they have a roll out area so you can scrub your settings after adjusting.

Do yourself a favor and make some leveling pads or just buy them, you'll be much happier.

good luck,
Scott

Boosted GP

I would say within a millermeter or 2, otherwise no point in doing it at all.

Mike

shinnster

ok, i ordered levelers for the scales,
Here is my plan

I'm going to try and find a good flat surface.
then i will make sure that the scales are placed where the tires would be for the car
then using a bubble level make sure that the scales are level
then use a laser level on one scale and make a marker so that on one scale i can mark on the marker where the laser hits. then i will move the marker to the other scales making sure that the laser point hits the marker in the same spot and making corrections if there need to be any.
Does this seem the best way to make sure that the scales are perfectly level and a good way to start the corner balancing?

Bullet01

iTrader: (7)

Shinnster-

Once you find level ground, measure your wheel base on the vehicle, this will give you a good starting point for where to place the scales. Then i would use the bubble gauge to level the pads. Once the pads are level to the ground you should be ok to put the car on the scales and start your corner weighting.

As for the laser level you can do it that was as well, but to me as long as the scales are level to the ground you should be ok.

Good Luck.

Scott

shinnster

bullett01
Wouldn't there be a problem?
lets say that three of the scales are exactly level with the ground and level with eachother. let say the fourth scale is 2 milimeters shorter then the other three. Let say i corner balanced the car in this situation. wouldn't the wheel at the fourth scale be less loaded then the wheel on the opposite side of the axle.

Balanced
FL FR
500 500
RL RR
300 300

balance with one scale a little lower than the others(lets say FR is lower)
FL FR
520 480
RL RR
280 320

I know this is just made up numbers but wouldnt one scale being off result in something lke this?

Bullet01

iTrader: (7)

shinnster-

To compensate for that problem of having 3 scales level and the 4th scale not level, i have come up with the easiest solution for you.

1. Once you have measured the wheel bases front to rear and side to side, place the scales on as level as possible ground you have to work with.

2. Level the scale plates with the scales in them using the bubble gauge.

3. Go to Home Depot or Lowes or what ever home inprovement place you have in town and buy the longest level they have (probably a 6' or 8').

4. Go to your local machine shop tool place and by these 1-2-3 blocks, they will help you for making sure everything is level. Im sure you can get these from any tool machine shop.
http://ec2.images-amazon.com/images/...V65957033_.jpg

5. once you have these partsplace the 1-2-3 blocks in the middle of the front pads, using the 6'-8' level place it on top of the 1-2-3 machined blocks and do your finally leveling adjustments on the front pads.

6. same as step 5 just on the rear pads now.

7. Since the level isn't long enough to reach a front right pad to a left rear pad (crosswise) you might have to use your laser level here.

The only thing i don't like about laser levels is that they tend to move with the slights touch not giving you an accurate measurement if you accidently bump it without knowing. plus the laser like to jump and is very sensitive.

I hope this helps, if not let me know, i have a buddy who Corner weights on the side and he would try to help you understand as well.

Bullet01

iTrader: (7)

Shinnster- do you understand this better?

shinnster

I think so but am still a little confused about using the 1-2-3 blocks
Why would i need to use those?
The only thing i can think is that they are measurd flat and i can get the center of the scales level.
Also would having the rears and fronts at slightly(less than a few millimeter) lower or higher make too much of a difference.
As long as the 2 fronts were at the same height and the 2 rears were at the same height then it would be "ok". My guess is that the cross weights would be close, it may not be exact, but if i couldn't level the rears and front to eachother then at least my cornerbalance shouldn't be too off right?
I should be getting in my roll of plates this thursday and will try the corner balance out that weekend.

Thanks for the help

Bullet01

iTrader: (7)

Correct!, those 1-2-3 blocks are machined perfectly flat and will help out tremendiously when leveling side to side.

Not alot of difference that you would notice, very minimal.

Correct again, see you got it now!!

Anytime! keep me updated, i'd like to know how it goes. If you get a chance take some pictures and document what you do. i'd like to see pics as well. Good Luck!!

BTW- these are also helpful if you want to order these or make your own- http://www.longacreracing.com/catalo...?id=94&catid=2

It's the Chassis Set-up / Tire Chart where you can log all your data/weights/changes/etc.... then you can keep it in a binder and log all your changes. It's a very useful tool. I tried to go on the site and blow the pic up as much as i could to see if it would print out. you might have better luck than me though. anyway .....Good Luck!!

Scott O.

nothere

iTrader: (23)

wish you lived out here, so I could borrow your scales.
big ticket item for one guy.
good luck

tahoeacr

iTrader: (3)

Got a fax? I can fax you a copy of one of my set-up sheets. Don't know if anyone mentioned about getting some slide plates to put on your scales. This allows you to change your settings without rolling your car off your pads. I saw alot of World Challenge teams using linoleum tiles for this(including the one I worked for). It works. Seems a little low rent to me for someone doing pro racing, but hey maybe one more reason why they weren't up front.

LDOGGYDIZZLE

iTrader: (1)

If corner weight are your concern, dont even bother if the scales arent perfectly level to each other. Yes a 1/4 can give false data. A half turn on a adjustable spring perch will shift a lot of weight.

As for the tiles on the scales, we use thick garbage bags. 1 or 2 is all you need. Cut and fold. The size should be as big as the size of your scale pad. To be clear, tire touches garbage bag, garbage bag touches garbage bag (why it slides), garbage bag touches pad. Make sure each one is the same thickness (folds etc) because this will make your scales unlevel again. This is very effective and neccesary to allow the car to settle on the scales and you can do changes/adjustments without needing to roll the car back and forth every time.

Mercenary3

iTrader: (1)

First of all, for "street driving", finding a relatively flat surface to do this on is more than plenty. Basically, for the street, you just need to be in the ballpark. Youre corner weights wil be off DRASTICALLY more when passengers start getting in the car, changes in fuel, etc than if the scales are off by a couple milimeters as others have suggested. On the street, I guarantee you will not notice a couple percent difference in corner weight sums.

Before track events, using some sort of leveling plate or level surface would be recommended. However, even more important than getting the last bit out of laser levels and all that crap is making sure you corner weight the car EXACTLY as you intend to drive it. A lot of people make that mistake. That means if you start your track day with a half a tank of gas and end with a quarter, weigh with 3/8's. If you dont race with a spare tire, take it out now. And obviously you need to be sitting in the drivers seat in an appropriate driving position when measurements are taken. Make sure you have someone settling the suspension AFTER you sit in the car, but before you take measurements.

kekek

iTrader: (22)

Garbage bags...good trick

Looking at your avatar I was about to nice work at Nationals this year! Then I noticed the sig too. Congrats