calculating ideal corner balance weights Options

[brant]

do folks around here calculate Ideal corner weights
we always do and usually can get within 1lb on each corner..


but I see everyone posting cross weights and no mention of calculated ideal weights...


for those that don't you should really look into doing it.

brant

[McMark]

Any leads on the process? (IMG:style_emoticons/default/confused24.gif)

[john rogers]

Hummm, not sure what "ideal" would mean? When we balanced the 914-6 every winter we went with equal weights side to side both front and also rear. This was done with me fully suited in the driver's seat, cool shirt cooler loaded, full fuel cell and engine warmed up so oil would be distributed as per race trim. We never worried about front to rear or cross weights since all the tracks we ran on were pretty much even in loading and if they ran clock wise or counter clock wise.

What I was surprised with was the fact that the car's weight would change from year to year and we could never figure out why? My weight stayed the same and no changes were made to the car after we did the big weight reduction with all the fiberglass bits.

[brant]

Any leads on the process? (IMG:style_emoticons/default/confused24.gif)

sure thing

I use a paper version of the same formula's and a calculator
(don't want to leave the garage and log into a computer)

if you do the (simple) math... you will find most starting points about 30lbs off in each corner after carefully setting ride height. (Sometimes a corner will be 70lbs off depending on how carefully you set ride height.)

by then making adjustments using the formula each time, you can bring the numbers closer and closer to ideal

we usually stop in the 1lb range

jacking ride height UP adds weight to that corner
lowering ride height takes weight off
you want to start with the corner that is furthest off in pounds from ideal

I recommend making any changes, one corner at a time
it takes longer but making multiple changes is more likely to set you in the wrong direction. (similar to jetting carbs... one thing at a time)

we roll off of the scales for each change and don't forget to resettle the suspension (bounce it a lot) and zero-calibrate the scales before rolling back on for the next measurements.

its a long process
a few hours minium, and a half day if you have had the suspension off.

[brant]

Hummm, not sure what "ideal" would mean? When we balanced the 914-6 every winter we went with equal weights side to side both front and also rear. This was done with me fully suited in the driver's seat, cool shirt cooler loaded, full fuel cell and engine warmed up so oil would be distributed as per race trim. We never worried about front to rear or cross weights since all the tracks we ran on were pretty much even in loading and if they ran clock wise or counter clock wise.

What I was surprised with was the fact that the car's weight would change from year to year and we could never figure out why? My weight stayed the same and no changes were made to the car after we did the big weight reduction with all the fiberglass bits.

ideal is pretty well explained in the link
the lack of fine tuning to ideal is why your weights were changing year to year
you can replicate total weight pretty darn close (5lbs or less) from year to year when you do this extra step to ideal

this is the detail step(s) that most people skip.

brant

[SirAndy]

do folks around here calculate Ideal corner weights
we always do and usually can get within 1lb on each corner..

but I see everyone posting cross weights and no mention of calculated ideal weights...

I never try to get all corners equal, i try to get the cross weights equal ...
(IMG:style_emoticons/default/shades.gif)

[brant]

do folks around here calculate Ideal corner weights
we always do and usually can get within 1lb on each corner..

but I see everyone posting cross weights and no mention of calculated ideal weights...

I never try to get all corners equal, i try to get the cross weights equal ...
(IMG:style_emoticons/default/shades.gif)

when using the formula for ideal, none of the 4 corners are the same as each other.... Each corner shoots for a different ideal weight. its just a fine tuning of the cross weights

[SirAndy]

when using the formula for ideal, none of the 4 corners are the same as each other.... Each corner shoots for a different ideal weight. its just a fine tuning of the cross weights

Ok, then that's what i do. Seems like the terminology is the confusing part ....

(IMG:style_emoticons/default/biggrin.gif)

[0396]

Any leads on the process? (IMG:style_emoticons/default/confused24.gif)

sure thing

I use a paper version of the same formula's and a calculator
(don't want to leave the garage and log into a computer)

if you do the (simple) math... you will find most starting points about 30lbs off in each corner after carefully setting ride height. (Sometimes a corner will be 70lbs off depending on how carefully you set ride height.)

by then making adjustments using the formula each time, you can bring the numbers closer and closer to ideal

we usually stop in the 1lb range





jacking ride height UP adds weight to that corner
lowering ride height takes weight off
you want to start with the corner that is furthest off in pounds from ideal

I recommend making any changes, one corner at a time
it takes longer but making multiple changes is more likely to set you in the wrong direction. (similar to jetting carbs... one thing at a time)

we roll off of the scales for each change and don't forget to resettle the suspension (bounce it a lot) and zero-calibrate the scales before rolling back on for the next measurements.

its a long process
a few hours minium, and a half day if you have had the suspension off.

I use a very same process as Brent....not down too the 1 lbs thought...he's the man too

[Woody]

I can get my car exactly at 50% cross weights. I am running delrin bushings that I turned on a lathe for a perfect fit with no drag. I think its like splitting hairs at that point.

[brant]

I can get my car exactly at 50% cross weights. I am running delrin bushings that I turned on a lathe for a perfect fit with no drag. I think its like splitting hairs at that point.

next time you corner balance, I would love to see you run your numbers and get back to everyone about how close/far off your rough numbers are...


for me this is an economical way to improve the car

for example: I figure I go to the effort of buying a better tire versus just a toyo because I want everything I can get out of the cars performance... So this is just one more way to improve the performance (although only slightly)

brant

[Woody]

I will probably go through the setup again before the season starts in January. I'm not sure I understand your process yet but I'll definitely give it a shot. I'll read through it again when I have time. These are my last balance settings.

[john rogers]

Humm, do you make the adjustments with you or whoever is driving in the car or do you bribe you wife to site there for all that time? I used to have to buy my wife dinner after she say through a balance session. You did not mention how level the area is that the scales are setup on? The set Black Forest in San Diego let me use had built in levels which was nice.

[brant]

I sit in the car...
fully race trimmed: 19qts of oil and 4 gallons of gas.

when I go to alignment, I put balast weights into the drivers seat to replicate

but I sit in the car when I corner balance.

I do my best of balancing my garage floor. I use exactly the same position and location for the dozen or so years I've been doing this
my buddy who is semi-pro on the dirt tracks has a beautiful metal table (like a celete bench) to scale his car on, but I've just been using a level floor. I have played with water tubing and strings in some attempts to check level in the past.

[Woody]

I use our brand new hunter alignment rack. I think its kinda splitting hairs though getting down to the exact pound. I may be wrong. That kind of accuracy will change depending on how much you ate, how well hydrated you are, and if you relieved yerself before a run. I am certainly not a talented enough driver to tell a difference at that level.

[john rogers]

Something to consider is the track where the racing will take place and what direction the turns are and are there any long ones such as NASCAR turns 1 and 2 at CA Speedway or NASCAR turns 3 and 4 at PIR or turns 8 and 9 at Willow Springs. If you are loosing time when the car does not feel solid and you let off and loose time then a slight jacking of the weight and outside wheels might help. We used to do this at CA Speedway and actually setup the car loaded towards the left and I could keep the pedal floored and actually take a drink, check all the gauges and talk to the wife on the radio through #1 and #2.