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More air less fuel · 08-06-2013, 09:59 PM

Last spring I spent some time setting the caster, camber, and toe on all four wheels. This is not all that easy on this car as everything is located with rod ends. The degrees of freedom are not separated in an elegant fashion either. (If I were to do it again, it would be different)
I had set the camber to zero (straight up) and the toe to zero (straight ahead) knowing that this would yield the lowest rolling resistance at a slight loss in directional stability. A compromise I was willing to accept....
Last week I had a nagging suspicion that maybe I should check and see if all my settings stayed put. Being as much of a headache as it is to check and adjust, I decided to get started. What I didn't mention was the fact that I do not have any alignment equipment or a rack system. All this is done with tight music wire, levels, squares and plumb bobs for reference. Toe is accomplished with bars on spacers bolted to the face of the wheels and rotating the tire on the ground 180 degrees to get a front of wheel and back of wheel measurement.
After filling the fuel tank and placing 160 lbs. in the drivers seat I checked front and rear wheel toe. As I thought, it moved. Both sets of tires had about 0.200" total toe. 0.100" at each wheel.
This is due to the fact that the suspension has "settled" because of engine and road forces during driving. Any clearance in bolt holes allows fasteners to shift and find a new home. When I made this car, I used the least amount of drill clearance I could get away with, but it all adds up. Many bolt holes....
I reset everything to zero and went on my usual test ride after filling the tank to an exact point with a graduated cylinder.
The first time out, I came home and didn't believe the numbers so I did it two more times today. This is kind of a pain is the butt, considering I have other things to do....But this is what really drives me. (no pun intended)
After calculating three times, the new mileage at a steady cruise controlled 60 mph is 85 mpg. It was 74. I realize this sound absurd, and that is why I did it three times. But it is true.
Just thought you guys would like to know.

08-06-2013, 09:59 PM	#150 (permalink)
More air less fuel EcoModding Lurker Join Date: Jun 2013 Location: Webster NY Posts: 15 Thanks: 0 Thanked 92 Times in 8 Posts	Wheel toe is not trivial.... Last spring I spent some time setting the caster, camber, and toe on all four wheels. This is not all that easy on this car as everything is located with rod ends. The degrees of freedom are not separated in an elegant fashion either. (If I were to do it again, it would be different) I had set the camber to zero (straight up) and the toe to zero (straight ahead) knowing that this would yield the lowest rolling resistance at a slight loss in directional stability. A compromise I was willing to accept.... Last week I had a nagging suspicion that maybe I should check and see if all my settings stayed put. Being as much of a headache as it is to check and adjust, I decided to get started. What I didn't mention was the fact that I do not have any alignment equipment or a rack system. All this is done with tight music wire, levels, squares and plumb bobs for reference. Toe is accomplished with bars on spacers bolted to the face of the wheels and rotating the tire on the ground 180 degrees to get a front of wheel and back of wheel measurement. After filling the fuel tank and placing 160 lbs. in the drivers seat I checked front and rear wheel toe. As I thought, it moved. Both sets of tires had about 0.200" total toe. 0.100" at each wheel. This is due to the fact that the suspension has "settled" because of engine and road forces during driving. Any clearance in bolt holes allows fasteners to shift and find a new home. When I made this car, I used the least amount of drill clearance I could get away with, but it all adds up. Many bolt holes.... I reset everything to zero and went on my usual test ride after filling the tank to an exact point with a graduated cylinder. The first time out, I came home and didn't believe the numbers so I did it two more times today. This is kind of a pain is the butt, considering I have other things to do....But this is what really drives me. (no pun intended) After calculating three times, the new mileage at a steady cruise controlled 60 mph is 85 mpg. It was 74. I realize this sound absurd, and that is why I did it three times. But it is true. Just thought you guys would like to know.