I finally corner balanced the car!!

[Xenonk]

This is going to be one LONG post! Get ready for some specs, all sorts of weights, lists of mods, etc etc. Here we go:

Driver: Keefe Lee @ 149 lbs. 5'-7.5"

Car: 2005 USDM Subaru Legacy GT Limited Sedan

Dealer Options:
-STi short shifter
-Auto-Dimming Compass Mirror
-OEM Rear Spoiler
-Security Upgrade Relay

Weigh-in & Autocross Setup:
-7/8 Full Tank Of Gas
-Removed All-weather mats
-Removed Trunk Tray
-Removed Jack & Tray
-Spare Tire left in bolted
-Zeal Coilovers (saved 16 lbs from stock shocks; 10 front, 6 rear)
-Cusco Vacanza Sway Bars (added 6 lbs from stock sways: 2 front, 4 rear)
-18"x7.5" R-1 Racing Rims (20 lbs each)
-225/40/18 Yokohama Advan 048 Tires (23 lbs each)

Static Weight (in lbs.):
Front = 1883 [56.53%]
LF=997 RF=886
Left=1700 [51.04%] Right=1631 [48.96%]
LR=723 RR=745
Rear = 1468 [43.47%]

Total=3331 lbs.

With driver in the car:
Front = 1939 [55.80%]
LF=1038 RF=901
Left=1700 [52.03%] Right=1631 [47.97%]
LR=770 RR=766
Rear = 1536 [44.20%]

Total=3475 lbs.

So basically, I was initially off by 29 lbs per corner, which isnt bad or hard to adjust.. just a few turns of the right front coilover and I was set. I decided to raise the car rather than lowering it because I dont want the car to bottom out during a turn.. it's pretty much as low as I want the car to drive before it starts to eat up any of the fender lining, Overall, I lowered the car about 2" off from the front stock height and about 1.5" in the rear.

The final result was (and I hit the optimum corner weights and it was not hard to acheive):

Front = 1939 [56%]
LF=1009 RF=930
Left=1808 [52%] Right=1631 [48%]
LR=799 RR=737
Rear = 1536 [44%]

Of course, if I really wanted to balance out the car 50/50 left/right, then I would have to do some serious modding of shaving the left side of the car from 1808 down to 1737 (71 lbs.. or move 35.5 lbs from left to right) making the diagram look something really odd to achieve of what I am at now:

Front = 1939 [56%]
LF=973 RF=966
Left=1737 [50%] Right=1738 [50%]
LR=764 RR=772
Rear = 1536 [44%]

Total Weight = 3475

That means I would have to lower my car EVEN MORE OF WHAT IT IS NOW on the left side and jack up the right side of the car significantly.. making the car weigh in the optimum of:

Front = 1939 [56%]
LF=969 RF=970
Left=1737 [50%] Right=1738 [50%]
LR=768 RR=768
Rear = 1536 [44%]

Total Weight = 3475


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Here are some other facts/specs of the wheels/tires I run as well that I can swap:

Stock GT 17"x7" rims + 225/45/17 Dunlop Super Sport Race R-Compounds Tires = 44 lbs.

SSR Competition 17"x7.5" Rims + 225/45/17 Falken Azenis RT-215 Street Tires = 38 lbs.

-------------------------------------------------------------------------

Most likely, I'll re-corner balance the car when the car is down to 1/4 tank of gas and raise the car up some so that I can have some room to mess with.. it's a very long and tedious thing to do when you want to completely balance out the car from left to right WHILE trying to keep your ideal ride height for various suspension set-ups.

I choose my current setup to be my optimum running setup.. (as the car on the track consume the fuel, the car will get lighter..) and the car will feel more nimble in the rear and feel more balanced. Normally I have a passenger/instructor with me when I run the car during track events, so even the "heavier" instructors wont throw my car off too bad :lol: :D :rolleyes: :p :lol:

I thought this might help you all understand the car more from what I am sharing wtih you all. If you all need to know more about my future mods and setups, I'll keep posting in this section for everyone's reference.

Keefe

[racerdave]

kewl. I will not go to this length with my car (street only, as I have a shifter kart for fun), but it is interesting to see how your car scaled out. I'd be curious about a bone-stock car too...

[Xenonk]

I would say a bone-stock GT Limited Sedan would be 3370 by itself..

Keefe

[Rexmobbin']

this was one of the main reasons i didnt' go with coilovers. corner balancing, just seems like a PITA. of course, if you want the best handling ride...

[Xenonk]

this was one of the main reasons i didnt' go with coilovers. corner balancing, just seems like a PITA. of course, if you want the best handling ride...

But it's not a PITA. Your stock car isnt corner balanced either out of the factory.. and for most people, they are more concerned in the dropped ride height than corner balancing.. most people cant tell the difference in a left turn from a right turn of car behavior. I wouldn't even consider corner balancing an issue if competitive autocrossing or track time is even on the list of goals to achieve for the car.

Keefe

[Unilat]

Ignorance disclaimer: I've seen the balancing pad at my local racetrack, but never really knew what the car guys did with it, and I'd never heard the term "corner balancing" before joining this forum. So - I've got some questions that hopefully will help me see the light :)

With driver in the car:
Front = 1939 [55.80%]
LF=1038 RF=901
Left=1700 [52.03%] Right=1631 [47.97%]
LR=770 RR=766
Rear = 1536 [44.20%]
Total=3475 lbs.

So basically, I was initially off by 29 lbs per corner, which isnt bad or hard to adjust.. just a few turns of the right front coilover and I was set. I decided to raise the car rather than lowering...
How do you come to 29 lbs per corner - it looks to me if you shifted that weight from left to right on the front (for example), you'd still be off by 80lbs or so.

Of course, if I really wanted to balance out the car 50/50 left/right, then I would have to do some serious modding of shaving the left side of the car from 1808 down to 1737...
This makes sense to me - it's intuitive.

That means I would have to lower my car EVEN MORE OF WHAT IT IS NOW on the left side and jack up the right side of the car significantly...
Can you explain this? Intuitively, it seems if you wanted to transfer weight from left to right, you would raise the LEFT ride height.

Thanks

[Xenonk]

Ignorance disclaimer: I've seen the balancing pad at my local racetrack, but never really knew what the car guys did with it, and I'd never heard the term "corner balancing" before joining this forum. So - I've got some questions that hopefully will help me see the light :)


How do you come to 29 lbs per corner - it looks to me if you shifted that weight from left to right on the front (for example), you'd still be off by 80lbs or so.


This makes sense to me - it's intuitive.


Can you explain this? Intuitively, it seems if you wanted to transfer weight from left to right, you would raise the LEFT ride height.

Thanks

It's looking at the optium corner balance numbers.. the whole idea is to get the CROSS CORNERS to balance each other out.. think of it as a chair with for fixed-length legs.. of course as people we can shift our body weight sitting on a chair to balance ourselves on a 4-legged chair that all legs are uneven.. eventually, we can balance ourselves pretty steadily cross corners (keeping most of the weight of our bodies in the middle of the seating area). But cars dont have a the luxury of moving weight within itself.. so instead, we lengthen or shorten the legs to keep the car from "wobbling" or evenly put a load on the car where all 4 tires have a better chance to touch the ground.. we also use cross-corner numbers because at the end result, you'll find the center point of gravity on the car from an overhead view.

There's a lot of what you can do in terms of shifting weight. But the idea of corner balancing is to get the cross corners total weight to equal the same (ie: LF + RR = RF + LR). This is how you know that you are using the car's center of gravity to balance the car.. imagine if your engine was actually IN FRONT of your axle or front bumper? The rear end would have significantly less weight by far. Or what if the Engine was placed on the right side of the car in the passenger seat? That would certainly change the numbers.

As for lifting the whole left side of the car, it doesnt work that way since the car is not 50%/50% front to rear.. it's a proportion of that. So you have to raise particular corners at certain heights to acheive such matter. think of it as a 4-point balancing scale instead of the typical 2-point balancing scale.

Keefe

[SoR]

In other words, you hight adjust each of your coilovers to shift weight to each corner (tire).

Which Zeals do you have and if it's not a secret, how long did it take you to get them?
I ordered Function-X for my Evo few months ago and they're still mining the metals for them over in Japan I guess :lol:

[Xenonk]

In other words, you hight adjust each of your coilovers to shift weight to each corner (tire).

Which Zeals do you have and if it's not a secret, how long did it take you to get them?
I ordered Function-X for my Evo few months ago and they're still mining the metals for them over in Japan I guess :lol:

That is correct, lowering and raising the ride height is how you corner balance the car (which I have talked about in the suspension forum as well).

I have the Zeal V6 with standard spring rates (8/6) which I will eventually change to 12/10 spring rates when I get the rebuild/overhaul on them when the time comes. It didnt take me no more than 2 weeks to get them as Racecomp Engineering is not only an authorized dealer, but also my sponsor. I will have some secret weapons stashed to keep people guessing "how did that GT do that?". I can't tell you guys everything that I did to my car. ;)


Keefe

[subiecity]

do u have to werry about balencing the car when u have just springs i think maybe its just me but it saeems my car sits a hare off balence from left to right maybe barley a quarter inch and i get a shimmy in the driver wheel when im driving between about 55-80 mph nothing too crazy but def really notciable wtf could it be? any suggestions mr keefe

[Xenonk]

You can only balance the car if you have ride-height adjustable springs and shocks (aka coilovers).

95% of cars that come out of the factory are not designed with corner balance in mind (but within a 5% difference if possible) simply because not every driver weigh the same (nor the amount of stuff that the owner carries in the car such as golf clubs, trunk junk, etc).

that shimmy is something else, check your tires or wheel weight balance.

[subiecity]

just to update u....the crankshaft pulley is the same for the legacy gt and the legacy2.5i.....lolol yea i got an account on legacygt.com now....im an offcial addict lol i get at u later online thanks again

[yamie700]

Just got back from having my car aligned and corner balanced. I put on BC-BR coilovers about 2 weeks ago. I guess I was good at adjusting ride height, because with no adj. at the shop my car had these specs (unlimited manual wagon with spare out/ my autox setup).

FL FR Total Weight w/driver 3551
997 958
RL RR
837 758

Cross 50.5%
Left 51.6%
Rear 44.9%

[Xenonk]

full tank of gas??

or are you about 100 lbs more than me?

[mwiener2]

^^wagon

[yamie700]

full tank of gas??

or are you about 100 lbs more than me?

I had just under 3/4 tank and I weigh 190.

I can't wait for the next autox, last time I had just put the coilovers on and was getting used to them, also I had 0 camber. Now I have -1 deg. for daily driving and the alignment guy showed me how to set my camber plates to allow about -2 deg. for autox.