On-line Training Program......
"Every Racer's Guide to
Go to our free training
Suspension Tuning 101 and 102.
We'll show you the two key
concepts and the "silver bullet".
See how we have set up the race cars that have saved our clients
seconds in lap time.....here is the link to our new website....
10 Biggest Suspension Set Up Mistakes -
most race teams have made:
Set Up Mistake No1: Not testing.
There are so many variables. No one can predict the perfect set
up, even for a spec formula where much of the suspension is fixed by the
rules. Therefore you have to do comparative testing. Our
Weight Transfer Worksheet gives you a good baseline set up and possible
directions for improvement.
As I write this, a sports sedan
driver, on TV (Speedweek) said "Not everybody can do it (go
racing in sports sedans). It's a big commitment (time and money) and it takes a
while to acquire the knowledge you need to make the car work."
Nothing will accelerate your learning curve like properly planned and
At Racing Car Technology, most of what we have learned has come through
testing. We have
made good improvements in car speed for our customers and gained
important insights in vehicle dynamics and car set up.
Set Up Mistake No 2: Not "reading" the tyres.
The tyres are the most important and most complex component of the
set up. Regular tyre pyrometer
temperature readings throughout a test day are very instructive. It is
arguably your second biggest
pointer, after driver feedback, as to what is happening with the car.
If you change to a different tyre, it is almost a given that there
will be setup changes that can make the car faster, even if it was
optimized on the old tyre. In general, a tyre with
more grip requires greater overall roll stiffness. Also, if the
car is wearing or scuffing the tyres excessively, it might be better with
less overall ride stiffness (stiff car tends to use up the tyres).
The WTW is exceptional value in helping you determine what is overall
relatively "hard", and likewise, "soft".
Set Up Mistake No 3: Unknown springs, unknown ARB's.
Many teams know their spring rates, but do not know the ride stiffness
(spring frequency) and roll stiffness of their car. The WTW is an obvious help in this regard.
As is our "bounce test" - a very simple way of measuring
directly, without calculation with motion ratios.
We expect race car front to rear roll stiffness to have a difference
of around 10%-15%, unless there is an overpowering reason to the
contrary. Many race cars have rear spring stiffness too
low, and are unlikely to be optimized at that, even if the driver is
only a little off the pace. We have been able to get such
cars on the pace with a rear spring change, sometimes rear ARB, and
sometimes roll centre height change.
Set Up Mistake No 4: Not doing a workshop set up.
Not have sufficient suspension travel or free movement (suspension
must have no binding). Suspension travel and spring stiffness, are
totally inter-dependent. You must specify one with a view to the
If you purchase a new race car, or a car from another race team, the
car will not be "set up". It costs too much to do a set up and
fully acquaint a new owner with what is going on. In any case, the
new race team needs to do their own set up that they understand, and can work with.
How often do you see some one taking advice on a set up change from the
car builder or faster competitor, and getting an in-conclusive result?
An addendum to Mistake No 3 - not
collecting (and using) data. We use and sell the DL1 data
logger from Race Technology.
Set Up Mistake No 5: Not having a plan for set up changes.
"If I change this then I
expect that. But if I don't get that, then I have my response
worked out, which I can implement, taking into account what feedback I
am getting." This is an ideal. We might never achieve
this level of understanding. The Weight Transfer Worksheet can
help by attaching values to some of the areas we have to think about.
For instance, are front and rear suspension frequencies in a range range
we expect? Is the percentage of roll resistance allocated to the
anti-roll bars in a range that will make adjusting the anti-roll bars
Set Up mistake No 6: Not having shocks valved in a range where
they can be effective as a tuning tool.
It is clear that any shock is better than no shock in terms of
controlling the spring. With no shock, the tyre grip is badly
degraded by the cyclical loading and unloading of the tyre.
The shock you want for tuning the set up - valving that works to control
the movements of the chassis - will be valved stiffer than a road shock,
and within a finer range. Once you are close, it is possible to go too
stiff, with just a small change.
Set Up Mistake No 7: Not understanding relationship between roll centre heights and
geometric vs elastic weight transfer.
This central to our understanding of how set up changes work.
Set Up Mistake No 8: Not understanding toe settings.
Set Up Mistake No 9: Over-reliance on caster, or other
suspension geometry setting, as the magic tweak.
Set Up Mistake No 10: Not exploring sufficient set up
options to optimize the car.