Can anyone give me the readers digest explanation of what corner balancing is and does? I am being told it helps alot on a track car.

Thanks

 

Here's a couple of illustrations that might help. Think of a table. All the legs must carry the same weight or the table will wobble.

Here is more detail that I wrote up when I did a homemade DIY corner-balance job on my 944. The principles still apply. Click on the links for more info from more experienced guys.

<a href="http://members.rennlist.org/dan10101/chapter_22_-_home_align_and_corner_balance.htm" target="_blank">Dan's Rennlist website - corner balancing</a>

Hope this helps.
DanD
New teener in the family..

 

I got a small bottle jack and drilled the base for a guage to measure the fluid pressure which relates to the weight on the jack. I welded a tube to the top of the jack which slide into the center hole of the wheel.

With careful use you can corner weight the car easily by jacking up each wheel until it just leaves the ground and noting the reading. I found that on my 944 the rears torsion bars were WAY off either from the factory or from some early work done to the car.

Art

 

Art, neat idea with the bottle jack! What type of pressure gauge did you use, where do you get these gizmo's, and what pressure range do you need on the gauge???

 

Art -

That does sound like a great idea. Please be sure to give John all of the necessary information. That way he can build the contraption and I can help him use it.

Paul

 

I can take a photo and post. I'm not sure how to do it, I'll have to look into it.

The guage is from McMaster-Carr, just a standard 1000 psi guage. You only need about 600 psi for the 914, but with my 944 being heavier I changed it.

The machining is easy if you have the tools. You could do it by power drill if you were motivated.

If anyone knows the quick way to post a picture, let me know . I will shoot one tonight.

The thing I found to be important was how you use it. You need to watch the guage as you are lifting the wheel and note when it stops increasing. That is when the wheel just comes off the ground. You can also slide a piece of paper under and when it just comes out is the point to note.

If you just lift the wheel and stop pumping you will get a false reading as the whole works settles. I think the seals in the jack settle and reduce the pressure reading. Any way, I found I could easily get to ± 30 lbs.

Art

 

Art,

Just keep in mind that as you lift the car with your jack, weight will transfer to the other wheels. So your system will not be 100% accurate. The actual method of corner balancing is by "weight jacking" another words, raising/lowering corners of the suspension to transfer the uneven loads.

 

I do realize that there is some error introduced with my method. Mostly I am trying to get the weights even for street use, not bias to any absolute percentage.

The idea came from helping a friend years ago with a race car that had device that worked similarly to this. I suppose a race car has less spring travel so the error might be less.

It is a good poor man's tool.

Art

 

Yeah.....thinking out of the box.

 

This is it.

<a href="http://boards.rennlist.com/upload/914corner.jpg" target="_blank">http://boards.rennlist.com/upload/914corner.jpg</a>

I could not get the photo to paste in, but this is the link to it. I guess you can just paste in to the url line and open.

Sorry for the lapse.

Art

 

Just out of curiousity how much pressure do you build up in the bottle jack this way I can get a gage that is more readable

 

On the 914-6 it was around 550 psi on the rear and less on the front. On the 944 it is more, but I don't remember exactly, less than 1000 psi. If you measure the bore of the jack when you have it apart you can calculate the actual weight and get a decent sense of total car weight. You can al;so calibrate with a known weight.

I once had my 914 on a set of 'real' scales and it corresponded to my data.

Art