Re: 4kcsq skid plate

[Richard Beels <beels@technologist.com>]

Assuming this is for PRO rally.  can't help on the points but.....

The virtues of aluminum (6061 T6 moderate price, very strong), steel
(cheap,strong but heavy), carbon fiber (very expensive,very light,very
strong) and UHMW Polyethylene (strong, moderate-high price, easy to work)
can be argued endlessly. We're using aluminum - 3/8" of 6061 T6.

You might want to double up the front lip or where it is necessary to bend
it. Add some reinforcing ribbing.  You want the plate to be strong.  You
will hit rocks and you will dent the pan.  Make the attachment holes
oversize. You WILL bend it and if the holes are normal tolerance, you won't
get it back on the car. Try to mount it with some kind of a shock absorbing
device between plate and the frame.  WHEN you hit rocks/stones, you don't
want the plate to be rock solid with the frame.  We use some extra
suspension bushings.  Leave enough open area to allow air to flow out of
the engine compartment.  The last thing you want to do is overheat your
engine while protecting it.  Leave some space between the plate and the oil
pan also because you're going to deflect the plate upwards when you do hit
those rocks.  You might also want to provide several "drain holes" in your
skid plate to allow sand and small gravel which find their way past the
plate to exit quickly.  Trapped rocks between the engine and plate can do
much damage when the plate is flexed during a "landing".  Oil change access
hole is optional.

Also, a  stone shield over the OE gas tank (if you keep it) is critical.
This can just be a piece of Low Density Polyetylene.  Stone shields over
the fuel pump, the fuel filter and the gas/brake lines that remain under
the car are also mandatory.  You may want to protect the rear control arms
too. You'd be amazed at how fast the flying stones will eat away the metal;
weakening the arms.

At 10:17 PM 8/20/1998 ,  Earl & Jean Hutson was inspired to say:
>  I need some help in  the construction of a skid plate for my 4kcsq.  type
>  and thickness of material, attachment points, etc.  Or anyone who has one
>  they want to get rid of.



Cheers,
	Richard
	88 90Q - <insert pithy witticism here>
	88 Golf GTi - PRO Rally