Im posting this here since its mostly the track guys that corner balance their cars.

Is it necessary to corner balance your car everytime you change the ride height on your coilovers?

On the street, i would want the ride height to be higher, and for the track i would want to lower the ride height. Does this mean that I would have to get the car corner balanced before and after every event?

I've looked around, and rates for corner balancing are around $150, which is a lot if im going to be doing it so often.

 

Yes, your corner weights and your alignment will change with the ride height.

What you can do, is get the car aligned and corner weighted at the height you race at. Then mark the sleeve, or count the number of threads so when you lower it again for the track it will be at the same height that it was corner weighted/aligned.

Your alignent will off slightly for street driving, but it should be okay. I dont have any major toe issues on my car after changing the ride height.

 

Camber and toe are the main alignment specs that change with ride height. Camber does not affect tire wear as much as toe so, as said above, you can just raise and lower the car between two ride height settings and then adjust toe. If the ride height change is small (1" or less) then you probably don't even need to adjust toe.

Make sure you use a part of the chassis to measure your ride height and measure it at the same spot, using the same measuring tool, every time. I use the flat, horizontal surface outboard of the front and rear jacking points on the rockers. Don't use the wheel/tire gap and be careful about relying on marks on the threaded collars to check ride height. Verify your adjustment by measuring the car to the ground on a flat, level surface.

 

can't you also measure ride height from the center of the wheel to the fender sheetmetal? it's basically the relationship of the spindle to the body, which should be fairly repeatable.

 

I never do. Camber angle affects spindle angle (to a small degree) and how good are you at measuring to the exact center of the wheel? What do you do if the wheel or tire extends outside the wheel well? Also, cars are in accidents and any bodywork or non-oem replacement panels in the wheel well affects the accuracy of the measurement. Its better, IMHO, to measure from a structurual part of the vehicle chassis to the ground.

 

For those that have corner balanced, do you add more negative camber for the track or change the toe for better turn in? Or do you track on your street alignment settings (assuming you don't change the ride height)?

 

Are you saying that we can do this instead of getting the car corner balanced?

 

Correct me if I’m wrong, but that will require a super flat floor. Wouldn’t it be better, for a DIY guy, to use the upper wheels arch to ground as a measurement?

My garage is pretty uneven. Enough that in some instances I can’t get my floor jack under the car…

 

I'm confused. What's the difference between measuring from the wheel arch to an uneven surface and measuring from the chassis to an uneven surface? What's most important is that the car is sitting level, otherwise the weight transfer from an unlevel position will affect the ride height.

Yes. Ride height is an alignment setting along with camber, caster, toe, CAI, etc. "Corner balancing" is a term I've only heard tuners use when they don't know what they are talking about.

Corner weighing is the more correct term and is a measurement process - all corner weighing does is give you the numbers. What you do from there is determined by your handling goals. Back in July I corner weighed my 2006 350Z and posted the numbers here:

https://my350z.com/forum/autocross-road/206029-2006-base-corner-weights-alignment.html

From those numbers I found that the cross weights on the car are almost perfect. So my plan is to not worry so much about the fore/aft weight balance and just make sure the cross weights stay balanced. Trying to hit a 50/50 weight balance with the car will take a lot of work and really isn't necessary to fast around a race track.

To get to a 50/50 balance (if that "magic" number became a goal) I would have to do pretty much all of the following: 1) physically move things like the battery and setting the engine back, 2) reduce the weight of parts that stay in their stock position like the hood and seats, and 3) adjust the heights of each corner using adjustable lower spring perches (coil overs). Just installing adjustable lower spring perches (coil overs) and moving corners up and down won't get you to the "magic" 50/50 weight distribution on a 350Z (if that's your goal). There's too much front weight bias.

 

You might want to get four 18" x 18" x 3/4" plywood squares and a dozen 18" square sheets of linoleum. Lay the plywood squares out and then using a carpenters level or one of the cheap laser levels, stack the linoleum until all four pads are level with each other. Then you can drive the car onto the pads and you've got a cheap, level surface to do your alignment.

 

Good idea.

I'll then be measuring at the wheel arches. My point was that the ride height will be repeatable if it’s measured at the car’s contact points to the ground. If the “bump” is under the tire, the whole car will go up and maintain a suspension geometry close to what it should be level. We’re basically removing one unknown factor or at least minimizing the effect of an uneven floor.

I’ll remember your plywood trick when I do get an adjustable suspension.

 

One point you guys are missing is that depending upon the ride height that the balance is best at he may not need to change it between race and road. The ride height and corner balance on my T2 racecar is perfect for the track, yet still provides enough ground clearance for most curbs, driveways etc., my car is still about 1.5-2" lower than stock.