ianellison

What actually is corner weighting?

I understand adjustment of the wheel geometry to be , toe in/out & camber, in other words correct wheel alignment.

I am being told that in addition a 964 needs corner weighting to get the perfect set up.

CB Red 964

I am not an alignment expert but have had this done a few times on my track car by an expert mechanic.

You put the car on four scales (one under each wheel) and put a driver in the seat or comparable weight.

You should have the same weight from side to side. A little more in the rear compared to front (55% / 45% as I recall).

Why different weights on the corners? Imagine the suspension adjusted all the way up on one of the front wheels so the car would be standing mostly on three wheels with the fourth barely touching the ground. That "barely touching" would show up as very little weight on that wheel. That is the best way to visualize the process.

Chimera

Good question. Tell us more.

Doc

dfinnegan

http://www.instant-g.com/Data/weightbalance.html

Chimera

Great link! Thanks!

Doc

Rennen

I always thought this was necessary to corner balance a car too, but when I had it done last week, the very experienced tech at the shop I went to said that he nevers puts any weight in the driver's seat when he corner balances a car. He said that the car distributes the weight of the driver equally to the four wheels and so adding weight to the driver's seat is unnecessary. this guy sets up race cars for a living, so I certainly didn't have anything to counter with. I'd be curious to know what others with more experience here think about that.

CB Red 964

Hmmmmm. I always bring some beer for everyone while sitting in the seat. I think they made that up to get the beer.

carnumber6

To be correct you do need to have the approximate weight of the driver in the car for a corner balance. If it is just a street car it is ok, but any "Good" alignment guy will put the weight in the drivers seat .. It does make a difference

Rennen

That's exactly what I always heard right up until last week. The question is, who is right? This guys sets up race cars and says not to do it with weight in the driver's seat. Is there a definitive answer except this is what people have heard? Has anyone done acorner balance w/ no driver weight, then placed a driver in the car to see what happens?

stevepaa

if the weight of the driver does not make any difference because the car balances it all out, then the weight of the engine would not make any difference.

Rennen

Yep, you've got all the same logic gears grinding that I had. I'm ony telling you what they said.

stevepaa

I knew that was why you were questioning it.

http://farnorthracing.com/autocross_secrets11.html

CB Red 964

Where is your seat located? If it is dead center then your wieght probably does balance out neutrally. Shifting probably looks a bit odd looking from the outside in....

Tom W

RedRS: Your tech is simply wrong. While it will have very minor impact on a street car, it does make a difference and any race car corner balance has the drivers weight added.

Colin 90 C2

don't forget that 1/2 tank of gas.