Re: More to lock or......

[Don Hoefer <hoefer@eng.pko.dec.com>]

Neil:

>  80mph in the rain is perfect hydro-planing conditions even with quattro. 
> I've felt it and it ain't tough to do.

Phil adds:

> As low as 60 in the ur-quattro in heavy rain.

Someone (who should know) told me that they estimate hydroplane speed for
aircraft as 9/5 * tire pressure and that this would be close for motor
vehicles also.  I have found this to be pretty good.  At 28psi this comes
out to just over 50 MPH.  Good tread raises the speed at which hydroplaning
will occur.  I have found my FWD Coupe to be very good until 63 to 65 MPH at
which point it will start to hydroplane in very heavy rain.  I run with my
tires at 32 psi.  Wider tires will lower the hydroplaning speed and narrow
tires will raise it.

I was once in Maine during a very heavy rain storm.  I took an entrance
ramp rather fast and stayed at 55 MPH (the speed limit then) on the
turnpike.  I passed a cop and then he stayed behind me for a long way.  We
passed everybody with me in the lead.  He never indicated that he wanted
to pass me and he had plenty of chances to do so.  After the rain stopped
he got off the highway.  I wonder what he was thinking?  This guy will do
something so that I can pull him over, or should I pull him over now?

Don Hoefer
'82 Coupe