Okay, might have solved the DIY corner balance/alignment

[matt f]

We use "HubStands" at the race shop. Also have alignment rack w scales. No difference in end result between HubStands and alignment rack. HubStands much easier to travel with.
Check their website, may give you some ideas.

Matt

[matt f]

Sounds so nice, I had to say it twice.
Sorry for double post.

[jittsl]

Just so we are clear - this will give you an excellent ride height setting but will not give you a corner balance. Corner balance is all about finding an equilibrium between the two cross weights by adjusting the ride heights not equalizing them. I don't know of a way to do a corner balance without scales.

[Elombard]

jittsl look up the "tripod method" its not scale perfect but its pretty good, especially for a street car and you can do it in your garage.

Actually I think these jacks would allow pretty good tripod corner balancing but not ride ht unless you can adapt them to the hubs.

[ZOA NOM]

OK, a simple resolution. Drilled a steel plate to fit over two lug studs, creating a block for the saddle of the jackstand so it won't slip off the hub. Viola!



The front hubs are already sloped inwards.




Now I can set level right at the center of the hubs with the water level, and the toe and camber adjustments should be much easier to reach. Toe and camber measurements can be taken right off the surface of the rotors.

[Dueller]

Lot of creativity and ingenuity her. Best solution I came up with was going in with another pcar guy and buying a set of used Longacre scales for $500 from dirt track guys. Or you can get a set of proform scales new for under $700....not pro a quality but fine for hobbyist.

[Elombard]

Now we are cooking with gas.

Ok let me take it one step farther - this is out there in the ether a bit......what if you bolted a simple plate to the side of the jack with holes for the lugs and....and....bolted a big caster on the bottom of the jack stand! then it would not bind when you were adjusting toe and camber and you wouldnt have to bounce the car etc.

I think they sell those big casters at HF for cheap.

Oh wait they would just roll out from under the car. Have to attach the jack stands to each other and they would not move freely.

Dern it....this jack stand jack is really greasing the wheels though. My Tractor Supply has them on sale for $39.

Can you show a pic with the water level attached?

[ZOA NOM]

Originally Posted by Dueller

Lot of creativity and ingenuity her. Best solution I came up with was going in with another pcar guy and buying a set of used Longacre scales for $500 from dirt track guys. Or you can get a set of proform scales new for under $700....not pro a quality but fine for hobbyist.

Thanks Jim, that's exactly what I've wanted to avoid. I wanted a repeatable method I could use for my race car, but at home in my shop. I plan to set the car up using this method, and then get it on a set of scales and verify the method.

[ZOA NOM]

Originally Posted by Elombard

Now we are cooking with gas.

Ok let me take it one step farther - this is out there in the ether a bit......what if you bolted a simple plate to the side of the jack with holes for the lugs and....and....bolted a big caster on the bottom of the jack stand! then it would not bind when you were adjusting toe and camber and you wouldnt have to bounce the car etc.

I think they sell those big casters at HF for cheap.

Oh wait they would just roll out from under the car. Have to attach the jack stands to each other and they would not move freely.

Dern it....this jack stand jack is really greasing the wheels though. My Tractor Supply has them on sale for $39.

Can you show a pic with the water level attached?

yeah, I was thinking the exact same thing, but it starts to get silly. I think there is enough movement on the jackstand saddle that it shouldn't bind too much when adjusting. I'll run back out to the shop and grab a pic of the water level setup....


Here's the bucket sitting on the lift table i use to drop the motor:



and a closeup on the tubing showing the water level at the hub:

[Elombard]

OK new Crazy idea

What if you attached a large bolt facing up through the saddle of the jack stand. Then made a simple plate assembly that attached to the hub that had a spot for the end of the bolt to rest in. Essentially each wheel is then resting on a point so you could adjust camber and tow with out much binding.

Would that be secure enough to work under or could that roll off? Nahh that wont be safe either

[ZOA NOM]

The only binding I see here is gonna be caused by the saddle of the jackstands as I adjust toe, but I'm only gonna want a sixteenth toe in on each side. Camber shouldn't be a problem as it leans, and the spring plates are ride height adjustable with a single large hex head set screw.


Thanks for making me rethink the jackstand location. I think the method got better.

[ZOA NOM]

Originally Posted by Elombard

OK new Crazy idea

What if you attached a large bolt facing up through the saddle of the jack stand. Then made a simple plate assembly that attached to the hub that had a spot for the end of the bolt to rest in. Essentially each wheel is then resting on a point so you could adjust camber and tow with out much binding.

Would that be secure enough to work under or could that roll off? Nahh that wont be safe either

I was thinking of an inverted angle iron piece on top of the jackstand post instead of a saddle, so that the hub rested on a single edge, allowing full movement, and maybe a large round plate that overhangs the lug studs all the way around instead of just the plate covering two.

[ZOA NOM]

Okay, I've spent some time measuring, and I've had to massage a bunch of numbers because my car is race-prepared, so it is significantly lower than factory. Front spindles raised 19mm were causing my math to be skewed, but I managed to finally remember that. So, the factory method of ride height measurement calls for 16mm of delta between the rear hub center and the torsion bar center, with the t-bar above the hub. Mine is 60mm below the hub, yielding a total drop of 76mm.

The front factory numbers show 108mm delta, with the t-bar below the hub. Mine are 198, but once you factor in the 19mm raised spindles, and the 76mm drop, I'm sitting at 103mm, which is 5mm too high in the front. This is when I realized I don't have a full tank of gas per the Bentley instructions.

Once I get the fuel load onboard, this method should yield reasonably accurate corner balance and ride height. Then I can begin the toe and camber settings.

[Elombard]

I like your idea, and you could have a little lip on the angle iron so if the car tried to roll forward the plate would rest against it. It will be interesting to see if the spindles can move in the saddle when you do the toe adjustments. I suspect they will move plenty and it will work briliantly. How accurate is the jacking mechanism? Can you make fine adjustments ok to get the car level?

[ZOA NOM]

Originally Posted by Elombard

I like your idea, and you could have a little lip on the angle iron so if the car tried to roll forward the plate would rest against it. It will be interesting to see if the spindles can move in the saddle when you do the toe adjustments. I suspect they will move plenty and it will work briliantly. How accurate is the jacking mechanism? Can you make fine adjustments ok to get the car level?

The jacking is typical of a bottle jack, which is very fine. Definitely within a millimeter accuracy.

What I need to do now is to clamp a 16 inch long straight edge across the rotor to take my toe measurements. The camber will be easily read with a digital level against the rotor surface.


When all is said and done, I believe this will be a very accurate DIY method, for the cost of four of these jackstands, a bucket and some tubing. Far less than a set of scales.

[patkeefe]

Did I miss the balance part of all this?

[ZOA NOM]

Originally Posted by patkeefe

Did I miss the balance part of all this?

The balance is achieved through equal measurements side to side, and maintaining the same ratio front to rear as the factory numbers. Same theory as the tripod method, but more accurate, IMHO.

[winders]

Still not seeing how you balance anything here.

[ZOA NOM]

Originally Posted by winders

Still not seeing how you balance anything here.

Then re-read it.

Level the car with the jackstands at the hubs.

Measure the deltas to the t-bars at the corners. Set the heights per the factory ratios. Balanced.


There is no magic here. Corner balancing is performed by adjusting ride heights at the corners. This method merely provides a method of leveling the car, and access to the adjustments.

[winders]

Originally Posted by ZOA NOM

Then re-read it.

Level the car with the jackstands at the hubs.

Measure the deltas to the t-bars at the corners. Set the heights per the factory ratios. Balanced.


There is no magic here. Corner balancing is performed by adjusting ride heights at the corners. This method merely provides a method of leveling the car, and access to the adjustments.

Except that you are making assumptions that are just not true. A perfectly level 911 is not very likely to be balanced. If a 911 was a perfectly rectangular solid object made of one material with consistent density, your method would work. But, that is not the case.

Yes, corner balancing is performed by adjusting ride heights at the corners. But, weight is not distributed evenly side to side along the longitudinal centerline of the car. That is why some sort of real balancing needs to done.