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14 October 2002 |
I
have been fielding a lot of questions re raising and lowering Minis, mainly from
our foreign brethren. The increase in exported Minis to farther shores has
revitalized interest in our precious Mini, indeed some new owners have rarely
seen one of them and are delighted by it's 'cutesy' character, unbelievable
road-holding and the discovery of the plethora of (relatively) cheap, readily
available spares and accessories. One of the first 'tuning tweaks' applied is
dumping the car in the weeds.
The
Internet has also played its part in increasing interest in the Mini. It also
provides near-direct links from the beginner ('newbie') or first time owner
with those who have extensive knowledge and experience in dealing with our
favourite little car. The down side to this is that the associated chat or
message boards where information is sought is also frequented by those of the
'a little knowledge is dangerous' brigade. Now I'm not belittling their
attempts and desire to help others, it's just that some of the answers are far
from correct, and support information dangerously lacking. And this whole
business of raising and lowering the Mini is just one such abused subject.
The
crux of the problem is the suggestion that fitting Hi-Los (or some such) will
afford you the convenience of winching the ride height up when carrying a
larger than normal load (say four full sized humans) then dumping it to the
floor for track days to 'maximise handling'. This simply isn't so for two very
important reasons - and many smaller but still significant ones. Just to get
those grey cells activated, I'm only going to cover those two important items.
One. Raising and lowering the ride height can
dramatically alter front suspension geometry - including tracking. When setting
up a car's suspension geometry, the very first parameter you set is the ride height
simply because as the car moves up and down, the suspension moves through
different sections of the arcs they describe. Each suspension component
describes a different arc on a different radius - the interaction of all
dictates what attitude the wheels develop. So raising/lowering the car will
change camber, caster and track on the front. Consequently this winching up and
dumping should most definitely not be done without checking/re-setting all the
front-end geometry. If you want to do this road/track day malarkey, set the
geometry at 'road' use height, then lower the car to your 'track day' height
and check what's happened to the front-end geometry. In particular the
tracking. If changes need to be made, either set the car up before you go, or
take some equipment with you to do it at the track. There are some very cheap
and simple to use tools on the market to facilitate this. The good news is
raising and lowering the rear doesn't change the geometry at all.
Two. Dampers. Not all dampers are capable of
dealing with radical changes in ride height. Many are aware of the various
dampers available for lowered ride height cars, although there seems to be a
general vagueness (even from the damper manufacturers) about when the lowered
damper is needed since referring to a difference from 'standard' ride height
generally means very little. And the fact the 'short' dampers are 3/4-inch
shorter doesn't help either. What you need to know is will the damper work OK
on your car. Since the main details of whether they will or not is the distance
between the top and bottom damper mounting points, how far apart/close together
they get in operation and the open/closed distance between the mounting points
on the damper, some critical measuring is needed. So why don't the
manufacturers give you the specific information you need? Suffice to say -
unless you take the necessary steps of measuring the differences you may well
end up scrapping them. Perhaps it's time I dug out my data on this and
submitted it for your delectation.
Useful
part numbers:
|
|
Pair adjustable spring
platforms/trumpets |
|
HILO-01 |
Pair struts for rear when using |
|
HILO-02 |
Short adjusting hex key for front HILOs |
|
HILO-03 |
Long adjusting hex key for rear HILOs |
|
C-AJJ3359 |
Top front damper bracket with relocated
mounting pin for cars lowered by more than 1-inch. Comes as a handed pair |
|
C-AJJ3361 |
Up-rated lower damper pin. |
|
C-STR687 |
Up-rated rubber spring - more
supple/compliant than Spring |
|
C-STR688 |
Stiffer rubber spring for tarmac race
use |
|
552018 |
Kayaba Gas-A-just front damper - very
broad operating envelope for raised/lowered cars |
|
552019 |
Kayaba Gas-A-Just rear damper to suit
above |
See inventory
for full range of standard/lowered height dampers.