Hello to all, as promissed i will try to demistify a little bit DAMPERS
adjusment for GP2.I'm not here to say that i totally know everything
about all aspect on DAMPERS setup, but i will give you my own
interpretation of how it affects handling, and most importantly how to
improve handling in qualifying session and raceday event.
How many time you've been to the limit entering or exiting a corner
(either low or high speed) and after hitting the cerbstones (in french
it's called "vibreur") all of the suddon your car overreact and goes
out of control and after few 360's your in the wall, or sand trap ???
So your reaction will be ,i will adjust my wings,springs or heights to
prevent this situation and make the car less responsive : WRONG!
You probably use too much BUMP/REBOUND DAMPERS either FRONT or/and REAR.
How do we adjust these dampers to prevent this situation ??? Let's
review what the dampers are made for.
BUMP DAMPERS: as it says,the role of bump dampers is used to keep the
tires from overreacting over a bump/cerbstone and keeping the wheel
on the track which translate in more grip.In the process of hitting a
bump,the tires will naturaly go off the ground,BUMP DAMPERS if adjusted
properly will prevent this situation. We can view this as the wheel
motion is moving UP.
REBOUND DAMPERS:
1-this is working in opposite direction (moving DOWN),and in conjuncture
with the bump dampers,it's going to put back the wheel
on the track, but it is not the primary purpose. While you're in a
corner (ex:left turn), let's view this as the outside wheel (right) will
work mainly in a UPWARD direction (because of car roll),and the BUMP
DAMPERS will take effect. At the same time the inside wheel (left) will
work in DOWNWARD direction,the REBOUND DAMPER will take effect. Got
the picture? We have to understand that if it looks simple at first
sight, actually both DAMPERS will work in conjuncture on the same wheel,
but the effects will be more pronounce on a given wheel depending if
this wheel is INSIDE(UP) or OUTSIDE(DOWN).
2-PRIMARY PURPOSE: The balance of the car,will be affect by the REBOUND
DAMPERS (rapid change of direction:S chicane and when entering/exiting a
corner). If you find your car overeacting when you execute a rapid
transition of direction,you should lower the REBOUND DAMPER setting.On
the contrary, if you find your car "Slugish",then compensate by
increasing the REBOUND DAMPER.
In the same manner OVERSTEERING is cured the same way as SPRING setting:
try to lower REAR first,increase FRONT in second.
UNDERSTEER is cured again as SPRING setting:decrease FRONT first,then
try to raise REAR DAMPERS setting.
NOTE: while your adjusting these setting,make small change at once,
then see what it's doing in a given corner / S chicane.Try to feel the
car:If you feel that it's overeacting in a rapid changeover of direction
, is it oversteering or understeering? Is it possible that it's not even
over/understeering but the DAMPERS setting are too HIGH? The same
question could be asked for a "slugish car".
These changes of setting should be performed on SLOW SPEED corners and
HIGH SPEED corners. Try to view the track as multiple portion. Where
do i have a "hard time" on a particular portion of the track,then
adjust your REBOUND DAMPERS, see the improvement. Is this modification
decrease speed at other parts? Can i find a "trade-off" which gives me
a better overall track time? Do the same in slow corner
NOW let's go back to our initial problem :(hitting the cerbstone,and
then out of control) 1- Remember BUMP DAMPER purpose, while hitting the
cerbstone, the OUTSIDE wheel will go upward, the bump damper will
compensate the effect,at the same time (almost) the REBOUND DAMPER (on
THE SAME WHEEL) will bring back the wheel to ground.
The other wheel will work primarly in REBOUND MOTION(downward movement).
If the adjustment of the BUMP DAMPER is too high compared to the REBOUND
DAMPER, the outside wheel will suddenly loose TRACTION. The inside
wheel will have an increased amount of load,the REBOUND DAMPER will try
to compensate (if the load exceed a certain level --> you lose grip).
"On the contrary of what i've wrote in previous article(experience
makes me learning)"
ADJUST THE BUMP DAMPER LOWER THAN REBOUND DAMPER on a given wheel.
Why? Well if BUMP DAMPER setting is higher than the REBOUND DAMPER,then
you don't give much chance to the wheel to regain the grip (overeact).
ex #1:If your entering a corner,and the car slows down.
When decreasing speed, the "LOAD" of the car will go on the FRONT TIRES,
the highest "LOAD" will go to the inside wheel, the REBOUND DAMPER
will work harder to cope with the increased load,if understeer
occurr,decrease the REBOUND DAMPER level on that wheel.
ex #2:If you enter a corner while in acceleration.
The "LOAD" of the car will shift at the BACK.The INSIDE REAR WHEEL will
have the greater "LOAD", therefore if oversteering occurr,decrease
REBOUND DAMPER level at that wheel.
(REMEMBER; view the track as multiple portion)
IMPORTANT NOTE: If too much PACKERS is in use,the effects of BUMP and
REBOUND DAMPER will have a lesser effect.At the extreme (excessive use
of packers),there will be no effect from DAMPERS.(REMEMBER THE
CERBSTONE?).
Try to set-up your car for each wheel (left&right and front&rear) to
maximize every portion of the track.
ex: This way you can gain traction in a slow corner (left turn) then
high speed (right turn),then a nice fast chicane, and so on...
***********************************************************************I'll give you one of my setting for Estoril. My lap are easily in low
1m21's and when i'm in shape low 1m20's, i do believe with further
fine tuning i can go 1m19's.The reason why i chose Estoril is: I find
this track difficult to setup since there's numerous different corner
approach and personally find it chalenging to sweep thru the uphill
slow S without loosing the back.
FRONT WING:14 deg REAR WING:9 deg
GEAR RATIO:1st:25 2nd:33 3rd:41 4th:48 5th:55 6th:60
FRONT ANTI-ROLL BAR:1500 lbs/in REAR ANTI-ROLL BAR:50 lbs/in
BRAKE BALANCE: FRONT:36,125 REAR:63,875
FRONT LEFT FRONT RIGHT
packers:3mm 2mm
fast bump:2 2
fast rebound:3 3
slow bump:8 7
fast rebound:17 16
springs:1400 lbs/in 1400 lbs/in
ride heights:26.5mm 28mm
REAR LEFT REAR RIGHT
packers:16mm 19mm
fast bump:2 3
fast rebound:3 5
slow bump:5 6
slow rebound:11 12
springs:900 lbs/in 1100 lbs/in
ride heights:47.0mm 50.5mm
TOP SPEED REACHED:305 KPH
PLANKs WEAR does not exceed .1mm
LOCK to LOCK WHEEL:12 deg
no driving help
USING WHEEL/PEDAL
**********************************************************************
Thanks for reading this article,hope i will receive input,(i accept
constructive critics),please reply via newsgroup.My next article will
be on ANTI-ROLL BAR and SPRINGS.
HAVE FUN, Eric
Hi Eric,
Thanks for taking the time to explain about these settings - I found
your article interesting but kind of misleading in some aspects.
You described the bump dampers as being mainly "Bump damping versus
Rebound damping" to create a balance. Actually you should consider more
to work on "Slow damping versus fast damping". "Slow" and "fast" do not
mean your speed, they mean the speed that the shaft of the damper is
moving relative to the outside of the damper (the housing).
Fast damping is related to the tyres. The job of fast damping is to try
to keep your tyres on the track as much as possible, and controls what
your tyres are feeling. This is tru of both bump AND rebound, not only
rebound as you described. This is a "fine tuning" option, and will
control what the car is doing over bumps, kerbs etc.
Slow damping is what the CAR/DRIVER is feeling. It controls what the
chassis is doing - weight transfer, acceleration pitch, braking dive,
roll etc. This is the one you will be adjusting most in order to control
the response of the car in different phases of the corner.
As I mentioned before, we are preparing a full guide for this in next
month's Sim News, so I shouldn't say too much here. However here is a
quick explanation of how to adjust slow bump and rebound in order to
control the entry and exit phases of a corner as explained by our
resident CompuServe expert who's preparing the guide at present (this is
his day job too - lucky sod! Doing this for real race cars).
Cornering phase Reduce oversteer Reduce understeer
Entry Front bump + Front bump -
Rear rebound - Rear rebound +
Exit Front rebound - Front rebound +
Rear bump + Rear bump -
Remember that the cornering tendency in the MID phase of the corner will
be determined by the wings, springs and roll bars, so if you're having
problems AFTER the initial turn in when the steering transient is over
and weight transfer movement has ceased, the overall balance of the car
is wrong. You'll need to adjust your other settings and then AGAIN
fiddle with the dampers to regain the balance during entry and exit.
For fast damping, Doug's advice is to pick a bumpy section of the track
you are bumping on and test it with fast bump at 0 and fast rebound at
2. Increase these gradually until the front understeers over the bump
and the rear oversteers - then back off 1 or 2 notches.
Remember, for fast AND slow settings, ALWAYS keep rebound higher than
bump, at least 1.5 times and often 2 or 3 times higher.
The main advantage of this is not necessarily a FASTER car, but one that
is more stable and predictable, and so you can push it to the limit.
Times already achieved with these techniques are :-
Jerez : 1:20.855
TI-Aida : 1:09.922
Estoril : 1:18.749
Spa : 1:48.385
Hungaroring : 1:16.299
This is (one part of) how the dampers operate on a REAL racing car, and
it seems from tests that GP2 operates like real life (I'm glad to say!).
Open to criticism and comments :)
Cheers!
John
PS - We hope to have the full explanation of this from Doug in the next
issue which will introduce also springs, roll bars and wings to this in
order to create an overall balance.
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On Sat, 31 Aug 1996 15:03:32 +0100, John Wallace
Hi John,
Never miss a chance to get that Aida lap mentioned, do you :)
(btw Silverstone 1:23.674 :)))
Cheers,
Richard
> Hello to all, as promissed i will try to demistify a little bit DAMPERS
> adjusment for GP2.
This kind of stuff, as well as the following posted by John Wallace, is
what I read r.a.s. for !
Bye,
Luca
Quoted text (7 lines)
>Cornering phase Reduce oversteer Reduce understeer >Entry Front bump + Front bump - > Rear rebound - Rear rebound + >For fast damping, Doug's advice is to pick a bumpy section of the track >you are bumping on and test it with fast bump at 0 and fast rebound at >2. Increase these gradually until the front understeers over the bump >and the rear oversteers - then back off 1 or 2 notches.I saw this question before, someone asking how to tell from the
telemetry when the car was under or oversteering. I wondered why anyone
would need to check that, you can easily tell while driving.
- When you enter a corner, does the car go where you point it, or do you
have trouble to reach the apex? As long as your speed isn't too high
when entering, the car is understeering at entry.
- Despite the car hitting the apex, do you have trouble to keep the car
on the road when leaving the corner, does it want to slide off the
outside of the track? This is exit understeer.
- If the car wants to spin on entry, this is oversteer, or if the rear
is "twitchy".
- If the rear feel like that after the apex, that is exit oversteer.
What you want to find is the right balance FOR YOU! That is why you
can't download a fast setup and drive it well, your style will differ
from another driver's. I look for a car that will go _exactly_ where I
point it on entry, and if the rear is a little twitchy I can manage
that. On exit I try to allow to get on the power asap, so again I like a
touch of oversteer rather than risking to slide over the kerbs or lack
steering response.
Drive a few laps with your setup and try to think where you are having
the problems. Problems are generally related to cornering, and so find
where most of your problems are (perhaps trouble to turn-in properly to
the apex) and then adjust the car for a touch more oversteer (less
understeer) during turn in. It's not difficult, just observe, think and
adjust.
Cheers!
John
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http://www.math.ohio-state.edu/~harmon/simnews
Venhuis) says...
First of all turn off ALL driving aids (including steering help and
opposite lock help).
Now, basically if your car spins it's oversteering; if it's difficult to
make it reach the apex of the corner, it's understeering.
--
Nicola Salmoria
