Got my car corner-balanced... why?

[vtluu]

Got my car aligned and corner-balanced at Roger Kraus Racing today. The corner-balancing bit was rather easy: they put my car on scales, found the cross weights (with driver) to be 1681 lbs and 1680 lbs (maybe if I'd taken off the front plate it would have been exactly equal ;)) and called it done (at least they charged me less).

Other factoids:
- Current weight of the car without driver, and ~12 gallons of gas: 3191 lbs. (So roughly 3125 lbs empty weight.) (New wheels, tires and lugs should take off about 10 lbs per corner.)
- Weight distribution with 170-lb driver: 60.9/39.1 front/rear, 51.3/48.7 left/right. (Time for me to go on a diet... :oops:)

So I'm wondering, if when corner-balancing you're just adjusting how much each corner of the car "pushes down" on the ground (geometrically speaking, making sure all four wheels are centered on the same plane), with the car sitting flat and level, doesn't that balance go out the window whenever the car isn't sitting flat and level (which is about all the time at a racetrack/auto-x course)? I.e. I know corner balancing is "what all the cool racers do" but how exactly does it help handling?

[wilson1]

Oh, the easiest way to balancing is to find someone exactly your weigh and put them on the passenger seat.

:lol:

[vtluu]

Thanks Wilson, I think I'll go to you when I need my teeth, not my car, aligned. :nana:

As it was explained to me:
- The idea behind corner balancing is to make the car behave the same turning left and right.
- If its corner weights are off you can say get oversteer turning left and understeer turning right.
- Weight transfer is always diagonal and that is what determines the ballance of the car, which is why cross-weights are important.
- For example, if the car was front 60 left / 40 right and rear 40 left / 60 right, the car might have perfect left-right front-rear weight distribution, but it would push turning right and oversteer turning left.

[dohcvtec]

i was at roger kraus yesterday getting my sol corner balanced :) brandon(guy who did your car) is a cool guy, my sister went to highschool with him. you wont notice the differences until you're pushing the car at or above 8/10ths :)

[chrisw]

you wont notice the differences until you're pushing the car at or above 8/10ths :)

which is something tam and I will be doing on sunday :)




Other factoids:
- Current weight of the car without driver, and ~12 gallons of gas: 3191 lbs. (So roughly 3125 lbs empty weight.) (New wheels, tires and lugs should take off about 10 lbs per corner.)
- Weight distribution with 170-lb driver: 60.9/39.1 front/rear, 51.3/48.7 left/right. (Time for me to go on a diet... :oops:)


At atwater last season, I was weighed at 3050 with no spare tire, 1/4 tank of gas and otherwise stock. Based on that estimate and your weight, I think we can easily get in the 2900lbs range. I may already be in that range with the super light buddy club p1 QF rims (lost over 10lbs/rim) , and fldenza flywheel (lost almost 9lbs there) Add a new exhaust and I should be doing ok.... :wink:

I pity those poor STI drivers

http://forums.nasioc.com/forums/showthread.php?t=700385

[dohcvtec]

you wont notice the differences until you're pushing the car at or above 8/10ths :)

which is something tam and I will be doing on sunday :)

where will you guys be on sunday? looks like i might be at sears point doing nasa hpde group 3 in my honda.

[vtluu]

ESP-legal weight redux for the Evo:
- Get rid of the AC (40 lbs)
- Go to non-HID lights (8 lbs)
- Mini-battery (20 lbs)
- Full titanium TB exhaust (60 lbs?)
- Lightweight rims (20 lbs)
- Lightweight lugs (4 lbs)
- Racing seats (20 lbs)
- Get rid of factory stereo and speakers (15 lbs?)
- Replace underbody braces with titanium (5 lbs)
- Lightweight flywheel (7 lbs)
- Coilovers (10 lbs)
- Tubular exhaust manifold (4 lbs?)
- Remove sound insulation (no idea... 40 lbs?)
- Remove wing (10 lbs)
- Aluminum roof (20 lbs?)
- Etc. (hollow swaybars, steering wheel, etc.)

The above totals close to 300 lbs which would take you to right around 2900 lbs... but some of it is pretty hardcore and you're definitely starting to sacrifice streetability.

It'll be interesting to see what Navid's Street Modified Evo looks like...

[chrisw]

- Get rid of the AC (40 lbs) Not gonna happen until it's a trailer queen
- Go to non-HID lights (8 lbs) I like my HIDs
- Mini-battery (20 lbs) done
- Full titanium TB exhaust (60 lbs?) I am thinking more like 45lbs with your standard aftermarket exhaust. The stock unit is pretty heavy
- Lightweight rims (20 lbs) luv them buddy clubs! My weight savings here is ~40lbs (10lbs/wheel)
- Lightweight lugs (4 lbs) done
- Racing seats (20 lbs) I don't think it's 20lbs. The stock seats are pretty light
- Get rid of factory stereo and speakers (15 lbs?) Trailer queen step
- Replace underbody braces with titanium (5 lbs) Not worth the effort
- Lightweight flywheel (7 lbs) done
- Coilovers (10 lbs)done
- Tubular exhaust manifold (4 lbs?) Not worth it IMHO
- Remove sound insulation (no idea... 40 lbs?)sure... when I get the EVO seam welded. :roll:
- Remove wing (10 lbs) maybe...
- Aluminum roof (20 lbs?)not practical, might as well buy a new RS
- Etc. (hollow swaybars, steering wheel, etc.)

Don't forget the RS doors and rollup windows, and you can remove the trunk trim.

[chrisw]

you wont notice the differences until you're pushing the car at or above 8/10ths :)

which is something tam and I will be doing on sunday :)

where will you guys be on sunday? looks like i might be at sears point doing nasa hpde group 3 in my honda.

we are @ oakland

[vtluu]

and you can remove the trunk trim.
Yup, done that (it was easier than cutting holes for the coilovers and strut bar :)). The trim weights next to nothing though, maybe 2-3 lbs...

Evo RS doors... did you mean the rollup-windows? The doors are otherwise the same. Well the unpainted door handles save the weight of the paint I guess. :lol:

I think you can remove the rear bench as well since it's not secured using "permanent" fasteners. (Pull one tab and it comes out.) But not the seat back since it's bolted in place. The bench weighs only a couple pounds though.

[chrisw]

and you can remove the trunk trim.
Yup, done that (it was easier than cutting holes for the coilovers and strut bar :)). The trim weights next to nothing though, maybe 2-3 lbs...

Evo RS doors... did you mean the rollup-windows? The doors are otherwise the same. Well the unpainted door handles save the weight of the paint I guess. :lol:

I think you can remove the rear bench as well since it's not secured using "permanent" fasteners. (Pull one tab and it comes out.) But not the seat back since it's bolted in place. The bench weighs only a couple pounds though.

The RS doors have aluminum crash bars instead of the steel bars we enjoy.

You can't remove the rear bench, it's part of the rear seat. From what I have researched off of evom, it's only ~15lbs tops for the complete rear seat.

[WOT]

So I'm wondering, if when corner-balancing you're just adjusting how much each corner of the car "pushes down" on the ground (geometrically speaking, making sure all four wheels are centered on the same plane), with the car sitting flat and level, doesn't that balance go out the window whenever the car isn't sitting flat and level (which is about all the time at a racetrack/auto-x course)? I.e. I know corner balancing is "what all the cool racers do" but how exactly does it help handling?


It's extremely apparent if you have a kart & it's wrong, the kart will turn in better 1 way than another. Due to caster settings & the amount of weight jacking that comes from caster.

so maybe then, If your running afteemarket coil overs, someone might run into problems if their not set correctly, i.e. corner weights.

You've got it right as far as mostly noticing it being wrong on a track when the car turns in or response better turning 1 way better than another.

How much caster are the evo's set up with anyway?

[chrisw]

How much caster are the evo's set up with anyway?

~3.5 degrees.

[earlyapex]

- Weight distribution with 170-lb driver: 60.9/39.1 front/rear, 51.3/48.7 left/right. (Time for me to go on a diet... :oops:)

ChrisW, how come vtluu's evo doesn't have the magical 50/50 f/r weight distribution your evo has???

:roll:

[vtluu]

Maybe he meant the cross-weights?

Or maybe it was the dead bodies he was carrying in the trunk. :lol:

[earlyapex]

Maybe he meant the cross-weights?

Or maybe it was the dead bodies he was carrying in the trunk. :lol:

He confused it with the cross-weights which has been my point all along but he fails to realize that.