talked up to be an essential modification for anyone who lowers their
AE86. You know the mantra... lowering the car will push the rear axle
housing to one side and your car will drive in circles... yadda... yadda.
So how does it work... this pushing to one side ? One end of the link
is attached to the chassis, and the other end is attached to the axle
housing. The OEM link has rubber in compression bushes at both ends
to absorb noise and vibration, and allow the link to rotate on the
fixing bolts. Aftermarket links have heim joints, urethane bushes or
hard rubber bushing in some combination.
They are designed to be more rigid under load, and have a threaded
section for adjustment. Here you can see a stock non-adjustable link
compared to an aftermarket adjustable link. For what it is worth, it
is possible to buy urethane bushes to replace the rubber bushes in the
OEM link if you want to cut down the amount of movement under load.
Now if you consider one end of the link to be fixed to the chassis, and
the other end free to rotate (move up and down) with the movement
of the rear axle housing, it can be seen that the free end will describe
an arc. And if the starting position has the fixed end 50mm above the
free end, the link will have a small angle. Lower the car by 50mm and
the fixed end and the free end will now be level, and the link will be
horizontal (and horizontal is a good angle for a Panhard Rod).
A simple calculation will show that in moving from 50mm above
horizontal to horizontal, the free end of an 835mm long link will move
a full 1.5mm to the left. That's about the thickness of two credit cards
or one CD. So depending on the difference in height between the ends
of the link before you lower your car, you will get less than 2mm of
sideways movement in the rear end. If you started 25mm above
horizontal and dropped the car 50mm, the rear end would be in exactly
the same place after lowering (I fkn love geometry
)Here is a pic of a Jubiride bolt-on bracket providing three height positions
for a custom length Panhard Rod. Basically it is the same type of correction
you get on the lower trailing links with traction brackets.
So for street driven cars, only people who can stand behind the car and
say... Yeah, for sure that axle is 1.5mm too far to the left... really need
an adjustable panhard rod. Which is not to say that cars with extreme
lowering won't legitimately need adjustment, or that hardcore racers
won't want height adjustment on one ene of the link to correct some of
the handling problems that come with extreme lowering.
Cheers... jondee86
