Theo, et Listers,
Ah, so many good postings, so little time!! Are we headed for a record
number today??
Fellow San Diegan Fred Puhn's great book "How to Make Your Car Handle" has
a picture that looks like your Corolla on page 95 Theo. Looks like maybe
it's lifting its inside REAR wheel though. ;-) But, on page 96 he uses a
picture of a Porsche at Willow Springs lifting its inside front wheel at
least a couple of inches off the road to make an important point. The
picture caption reads: "If your car lifts a front tire off the road in a
turn it has too much front roll stiffness, too little rear roll stiffness,
or a combination. A car on three wheels generally cannot corner as fast as
on four wheels due to the excess roll after the wheel lifts off. Change the
roll stiffness so that the tires al remain on the road in a steady-state
corner. Adjusting roll stiffness to tune the suspension has no effect on a
three wheeled car." I remember watching a bunch of Porshes racing at
Riverside and every last one of them lifted their inside front wheels, just
like Fred's book shows. But then, we all know how smart Posche owners are,
now don't we!!
You are right that, in stock form, the Tiger's chassis isn't stiff enough
to do justice to the kind of springs and sway bars you would use for
performance purposes. A good roll cage will help this problem a lot as well
as adding to your personal safety, both on the highway and on the track.
All of these considerations notwithstanding, I would urge everyone who
wants to improve the handling of their vehicle, Tiger or otherwise, to
upgrade the springs FIRST and then add sway bars primarily as a means to
fine-tune roll stiffness. I would think the way to do this right would be
to start with no sway bars on the car and work with just the springs front
and back until you get them just about right so you control total up/down,
dive, roll, roll steer, understeer/oversteer, etc. to about as good as you
can get it, according to your own particular criteria. THEN, add modest
sway bars front and rear - not so much to add more roll stiffness, but to
give you an easy means to adjust the roll stiffness. Of course, this
implies using sway bars with adjustable stiffness.
Looking at the picture of the disc brake setup of Doane's car on page 157
of Mike Taylor's book, I think I can see some rear sway bar hardware, but
it's hard to tell for sure. However, for the reasons I given, I would find
it surprising if a race car didn't have some means like a sway bar for
easily adjusting roll stiffness according to track conditions.
Finally, I think you also tend to overemphasize the front end heaviness of
a Tiger. In fact, once you get the right motor mounts in your car and get
the engine back where it belongs, the weight balance is really pretty good.
If you work at it a little with fiberglass hood, aluminum heads, etc., you
can probably get it to 50/50. But the fact is, when some of the best Tigers
run against other marques at autocrosses, and at vintage races, etc.., they
do damn well. And at the Tigers United events, the top times are usually
either in Stock or Personalized class. So maybe the message is there's a
lot of improvement you can make in your Tiger while keeping it still
"Stock", but it's a lot easier to make it worse than better if you don't
know what you're doing. (Not that anyone on the List answers that
description. ;-)
Well, TTFN,
Bob
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