Quoting Rob P <fristpenny@xxxxxxxxxxx>:
> I wasn't really looking for a poll when I made the original post. I just
> saw an interesting Imperial and figured that somebody else might like to see
> it. I like it.
Rob, I have to agree, I like it too. The look is refreshingly different.
But...
> I have to disagree with D2's analysis (big surprise ;) that handling may
> suffer because the car can't lean in the corners. The lean these cars had
> in the corners WAS a handling problem.
Rob, sorry I did not make it clear. The car will lean during turning, with or
without these "fancy" tires. The degree of lean for a given curvature/speed
cobination is a factor of track width, spring stifness, and sway bars. The
tires play no factor, assuming that they hold on to the road. The problem is
that as the car leans, the tires lean with it. As a result, a much wider,
stiffer, low profile tire that leans along with the car will lose contact with
the road a lot more than a skinnier high profile tire with much lower stifness.
So, there is no question in my mind that the above radical tire conversion is
NOT an improvement, unless you do a lot more additional modifications.
If lean is totally objectionable (its not to me, that's partly why I drive old
cars), there are modifications you can make to reduce it significantly by
increasing roll stifness, and then you can probably take advantage of these
"better" tires. You could install thicker torsion bars, say 1.2" diameter (you
would have to have them made, as I do not think anybody produces them) and you
can use a simlarly thicker front sway bar, install a rear real thick sway bar,
and add an extra leaf or two on your rear leaf springs. You would probably
need stiffer bushings everywhere (teflon may be) to reduce suspension
deflections under the much higher cornering forces. Doing all that will
significantly reduce body lean, and then, a super low profile fat tire will
stay flatter on the road under hard conrnering, and may work better. However,
it may take a lot of trial and error to tune the suspension to these new
radical tires, and the final product may not drive like an Imperial any more.
And if you want done right, it will be very expensive. You would still have to
deal with the shorter life of ball joints and bushings. But this way, you will
probably have the best handling 5500# car ever made (with drum brakes all
around if its a 66! :)).
I am considering a far milder conversion for my 68 Sedan in the far future.
Extra heavy duty shocks, thicker sway bar, rear sway bar, and slightly stiffer
rear leaf springs would probably work better than stock in terms of handling
(with deterioration of ride of course). If I changed tire size, I would get a
245/70R15 or 255/70R15 (notice, the profile does not drop below 70, and I use
the stock rims, parly so I can use the stock wheel covers). This would
maintain the diamater and the gearing of the car, plus it would be feasible to
get better speed rating, which is the main reason for all that (I have never
seen a 235/75R15 with better than S-rating, good for 112 mph continuous). I am
not interested in a Porche-like handling Imperial, but I would not mind
improving some one of my Imps, while the other remained stock. I think that
driving skill can compensate much of the "shortcomings" of you car compared to
a modern, as long as the car handles in a predictable manner.
> I personally feel that extra
> traction and less lean are GOOD things for my car.
I too, that's why I use radials. The body lean does not bother me that much,
and the only reason I would attempt reducing lean is so I can use the 70 series
tires with better speed rating. While excessive lean can be very bad, I do not
think Imperials lean excessively, for a luxury car.
> Ride comfort will certainly suffer because you're losing all the tire flex.
> To the extent that was designed into the suspension you may have a problem,
> but come on, the car is 37 years old. There have been some advances, it
> doesn't make sense not to take advantage because "the car was designed as a
> system."
Actually Rob, that does make a lot of sense. There is a lot of effort going to
tuning the suspension of the car, and all the parts work together, so that the
end result is more than just the sum of the components. And the OEM's have a
lot more resources than you and I, or even the aftermarket manufacturers, to do
it right. That's why Chrysler, with their superior engineering, made large
cars handle far better than Ford's and GM's (same thing for Chrysler engines as
opposed to other mass produced GM and Ford engines). And the tires are a very
significant part of the suspension "package". It turns out that changing from
bias-plys to radials is a relatively small change that enhances the way the
suspension works. So, overall, we are using advanced technology already (if
you want to call it that way, many Europan cars came standard with radials in
the late sixties). But going to a 50% or 40% profile tire with 265mm section
is too much of a change, that its unlikely to be productive.
> I know this would eventually denigrate into a points/electronic ignition,
> radial/bias ply debate, so I won't continue arguing with everybody. I still
> like them and I don't expect you to. The only way to tell how they are on
> the car is to drive it.
Liking the looks of something and actually making a handling improvement are two
different things. Yes, the real way of knowing for sure is by driving the car.
However, before spending a lot of money on an expensive experiment, it may be
best listening to people. Then, you may be able to spend your money more
efficiently towards "improving" your car the way that pleases you (improving is
in quotes, because what you or I consider an improvement others may not
consider it so, but as we already agreed, all that is subjective).
D^2
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