I did it!

I made efforts yesterday on BC7 SUBARU Legacy LSi US model in spite of cold and chilly weather condition.

Before checking wheel alignments and constructive geometries set back and swung rear end were checked finding out no effective differences.

Introduction:

There are two habits on automobiles, right side or left side tendency habit.

Then such kind of automobile may exist that runs straight with stability.

For long time I've been looking forward to know the possibility to adjust general cars in such a condition?

I had been trying to adjust may automobiles to establish the constructive geometries and wheel alignment asking to the factories, even to the instructor's in Nagoya city who was Hunter company's one.

No one could satisfy my only desire just to run straight!

The time was about 10 years ago that I had made up my mind to do that by myself, for myself and with the DIY instrument of myself.

I wanna report here about my constructive geometry and wheel alignment procedures because considerably favorable results were obtained.

Purpose of this experiment:

To know the possibility to adjust the automobile to go straight, in another words the possibility to eliminate the habit of lateral oblique running.

To know how accurately the automobile can be measured and adjusted, what'll be the limitation?

What element in three dimensions is affective on the steering habit? What affects most and how much on the habit?

Especially the toe effect caused by camber thrust?

Also the transient changes of toe effect due to the change of the rate of the thrust in the different speed ranges.

The possibility to measure the three dimensional inclinations, to adjust adequately, to fix and to tighten at one gravity circumstances. To do these procedures without errors, very special arrangements and know hows must be required.

Method of experiments:

Two devices were created, one is vertical incline scaler with 1719,750mm radius pendulum combined with hub adapter, another is horizontal inclination scaler with LASER pointer on level gauge in combination with hub adapter promptly.

The reason of radius length is to read 2minutes angle value as 1mm length on the scale.

Level gauge is of course calibrated on the two level dimensions and LASER beam direction was also precisely calibrated.

Angle values and distance values were tried 5 times and highest and lowest datum were eliminated and the average of residual 3 datum were adopted.

Results:

Front;

Camber R minus 37,1min., L minus 37,2min.

Total toe 0,95mm in (tire)

Rear;

Camber R minus 45,4min., L minus 45,7min.

Total toe 2,2mm in (tire)

Thrust angle plus 16,20sec.

(With equivalent weight on the driver's seat)

Consideration:

How are thing going there, but somehow a car with continuously troubles, let it go, but somehow I do not like. Now I have a latter one as NCP10 Vitz. Consideration about this emotional problem on Vitz ends up to some physical condition, pointless sense of insecurity. Wheel alignments and constructive geometries would be checked again after putting the equivalent weight on driver's seat as performed on BC7 SUBARU Legacy LSi US model yesterday.

Same experiments are going to performed one by one, SXE-10 TOYOTA Altezza, EP82 TOYOTA Starlet and XH200W OPEL B-Vectra. Especially Altezza would obtain good results.

The affair yesterday, establishing the wheel alignments and constructive geometries on BC7 Legacy, was an amazing feat! Under the condition with burdening equivalent weight on driver's seat position.

The successful satisfactory leads to self confidence in the wheel alignment technology.

I feel like that I have arrived at a dawn point at the end of a long dark、over 10 years interval.

Conclusion:

Self stability while straight running far increased and steering adjusting actions remarkably decreased.

Stays on the same running line after eye points movement.

Putting the equivalent weight on the drivers seat is an indispensable requirement if the reproduction of actual driving condition is desired.

Try not to loose accuracies in every steps to obtain reproducible datum.

Reference:

Hajime Date. (1991) . Introduction of Wheel Alignment . Coordination Theory and Practice. Railway Japan Co.