Four Items - Kinda Long

["Al Powell" <APOWELL@agcom.tamu.edu>]

The estimable Dr. Myers wrote:

> I run my 36 psig rated tars at 45 psig routinely.  I get sharper cornering
> and more uniform tread wear across the entire surface instead of just
> scrubbing off the edges right down to the steel with lots of rubber still
> left in the center of the tread.  My tars wear longer as a result.
> How high can you go without risking things like blow-outs, popping 
> tires off of rims, etc.?  I dunno, but 45 psig ain't there yet.  

Prob'ly true - but I would be reluctant to do so on a REALLY hot day 
for a long trip.  IMHO, heat buildup is the main concern with running 
tire pressures high. I do this for auto-x's in my 280 ZX but bleed'em 
back to max/rated pressure afterwards.  But I'm in TX where the roads 
should say "Sunbeam" and come with waffle marks across them.....

Of course, there is a safety factor for heat buildup built in - but 
it can be expensive to find out when you've exceeded it.

Next item:

> Ya know, I've never fully understood the concept of double clutching, neither
> have I figured out how to do it.  Do you actually push the clutch in, take the
> car out of gear, let the clutch out, push the clutch in, put thet car in the
> next gear, let the clutch out?  I'm just so confused!

Double-clutching is a technique designed to match the engine and 
transmission gear speed to the speed the car is driving **before **
engaging the clutch.  I find that using this actually increases my 
clutch life!  The procedure is most often used for downshifts 
in passenger cars, as upshifts are normally not a problem. This also 
implies that the driver is braking while shifting, making the 
heel/toe technique desirable.  The result is that you can use full 
braking from the brakes, PLUS full engine braking.  When done 
correctly downshifting, it provides a smooth, continuous, impressive 
braking surge that feels like you just hit 10 inches of water!  But 
let's say you're just shifting down while double-clutching-

Normal procedure, assuming a 4-3 downshift:

1) Push clutch down (disengage) and shift to neutral;
2) Puch accelerator down to speed up engine to approximately **the 
speed the engine will NEED to be running when you actually engage 3rd 
gear**.  Got it?  
3) Engage clutch, tranny still in neutral.  This forces the *gears* to 
spin at a speed related to the engine, and it's turning fast;
4)  Disengage clutch, shifting into 3rd as you do so - the lever 
should pop right in, as the gears are alredy spinning and you don't 
have to wait for the sync rings to spin the gears up to engine speed.
5)  Re-engage clutch to finish down shift to 3rd.

When executed a few times, it becomes a trained reflex and and can be 
accomplished VERY quickly.  It is used by the high-end racers, whose 
gear boxes shun such niceties as synchros, and by those who use its 
virtues for braking and other maneuvers.

If I have related the process incorrectly (I've been doing it so long 
I don't think about it any longer - I just do it) I'm sure one of my 
learned (read: hot-foot) colleagues on this list will correct or add 
details.

Third item:

Phil Ethier commented about Mike Myers' paint problem on his Talon:

> I don't think this is a good idea.  If the stuff will come off with a 
> fingernail, it is not stuck on all that well. Polishing it will not work 
> all that well, and at the expense of the car paint.  Use a bigger 
> fingernail!  A plastic ice scraper perhaps.  Keep the edge scrupulously 
> clean, as any grain of sand or the like stuck on it will scratch your paint.

Agreed.  Take it off manually while you reduce the world's beer 
population.  Patience can be rewarding.  I'd go VERY easy with a 
scraper of any kind.

Finally (sorry for the long post.....)
 
David Powell <dpowell@mdtech.is.ge.com> wrote:
> This weekend I might try to put the rear pads on.  I noticed
> they were just about gone when I was bleeding them last weekend.  Does anyone
> have any suggestions about where to purchase the accumulator?  How much I
> should expect to pay?  Is "good used" good enough for this part.  I don't
> expect to take this car to 300,000 miles so it won't need to last forever.

David - before replacing pads, mike the rear rotors and make sure 
they're not too worn.  Audi uses thinner rotors than other manuf's, 
and they recommend replacing rotors along with pads.  If thickness is 
questionable, replace them - but don't buy 'em at your dealer.  Ask 
this list for sources.  You don't want to run those rotors too thin!

Re the PA - two schools of thought.  The PA is a part that wears out, 
but it costs about half for a used one.  They only take about 45 
minutes to replace, and you can easily do it yourself.  Among others, 
<AUDIONLY@aol.com> who reads this list can supply new or used.  (No 
connection - I just think Peter, the owner, is a good guy with fair 
prices.  End'a commercial...)  A guaranteed used PA will run $130 +/-.
 
********** A Washington State Cougar in Aggieland (aTm) **********

Al Powell                           Voice:  409/845-2807
Ag Communications                   Fax:    409/862-1202
107 Reed McDonald Bldg.             Email:  a-powell1@tamu.edu 
College Station, TX  77843-2112
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"There are two kinds of truth.  There are real truths and made-up 
                    truths."   (Marion Berry)
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