Bob,
Thanks a lot for a long and informed reply. Will check up the vendors, I
have catalogues and adresses. In the meantime, some comments and some
more questions :-)
> And be careful that you don't make things so low that
> your roll center is below the ground!
What happens actually when the roll center is below the ground? However,
it appears that the best position for the roll center is above the car,
then the car would lean into the turn, or maybe I have got everything
backwards...
> The easiest way to lower a car is to go with lower profile tires. With a TR6
> and 225/45 tires, you lower the car by something like 1.5 inches. That's a
> lot, believe me. You didn't say how you intend to use your car, but in the
> 'States, using Hoosier DOT radials 225/45-15 will get you into the ballpark.
> I happen to use 225/55-15's and they lower the car a lot too, though not as
> much as the 45's.
In Norway those tires would be illegal on my car. We are only allowed to
put on tires that are within +/- 5% of the standard roll diameter, which
in practice means that 205/65-15, or equivalent, is the smallest I can
put on it. Strange, really, given that the PI-TR6 came with 165-15 and
if my car where a PI then I could legally lower the car even further.
205/60-15 seem to be widespread on the English PIs (the only difference
between the Carb and the PI seem to be the final ratio, the chassis and
geometry should be the same). Right now I have a new set of Nokian NRT2
T-marked 205/70-15 on it. Pretty tall, but still a little bit less than
stock. The 225/55-15 are 7% smaller, well outside my (legal) options.
>.... For the
> ultimate in adjustability, you can saw off the ends of the upper a-arms and
> weld in some threaded inserts and use heims joints to give you even more
> adjustment.
Think I pass on that one! :-)
>
> Now the last word is: if you start playing with the suspension geometry, be
> prepared to spend a lot of time sorting things out. Give the folks that
> initially designed the things some credit - they most likely did a lot of
> work to get what's there.
Just wondered if my car is the way the engineers really designed it, or
if it has been altered to meet bumper ride height and things like that.
>From my memory I am sure to have read somewhere (maybe it was
Kimberley's TR6 book) that the TR6 at some point where raised in the
front for that reason. If that is the case, there should be an optimal
way of setting up the front suspension, and still keep the car the way
it was originally intended (i.e. before government legislations changed
the set up of the car).
Anyway, I got the car back from alignment shop, and it has now 0.30 deg
positive camber (unladen) on both sides. Would have liked that number on
the other side of zero though. But if I am to go through the front with
new springs etc, I can wait to have it fixed.
Best, Lars
74 TR6 - soon to be taken on summer holiday trip around Norway.
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