Hello Marcus,
What, in your opinion, is then the reason for not running?
As I said, they do run more this year, due to the lack of track testing,
but if you go a few years back, you will see, that the top teams would maybe only
run for a handful of laps in FP1. Why??
You can allways learn something - agreed, but running an F1 car is not cheap,
and with limits on engine and g/box use, you have to choose wisely.
To account for the "rubbering inn" effect, you need expirience, and is at the end
an assumption or guess. And yes, I agree, that if you have a downpour or a dramatic
change in temperature, you are left to do the best you can under this new condition.
But what is the probability for this to happen?
As far as your expirience with this particular car goes.
Well you got yourself in a bit of trouble here (IMHO)
.
It sounds like that there was little, which did not change on the car.
It would help to know a bit more about the car in question, otherwise it is not possible to make some valid comments on it.
But let´s have some thoughts.
If I wanted to tease you a little bit, I would say, your dampers where the main problem.
- just kidding
Let´s start with the tire. It looks to me, that you have not the optimum tire for the car in question. Now there are maybe good reasons for it, life is not perfect, and you have to make the best of what you got.
But if it is the "wrong" tire to start with, it will affect all your other setup options.
This goes for many other areas of the car as well. Because one thing follows onto another, and these small compromises will add up in the end.
If you have worked (or still work) in the field of dampers, I assume you have seen this often. Dampers are very important and a very powerful tool, no question about this.
But, in my expirience they are also (especially in junior categories), the tool which is abused the most.
Often they are used to fix other problems, because it is far more easy to make a few clicks, then for example change your suspension kinematic to get a better roll centre height, or to fix the bumpsteer/torque steer problem that you may have.
I´m sure you will have seen, some strange things in your field of work.
Things wich may make no sense at all, until you understand the underlying problem.
An example would be, the use off crazy stiff springs, to compensate for roll centre, bumpsteer, camber loss due to roll, or stiffness issues.
At times it is hard to get your customer out of a rout, especially, when what they did has
made their car faster.
If the car in question was (just as en example) lacking stiffness in the bodyshell and/or suspension, and this issue was fixed with the used of an welded in roll cage,you are most likely to stiff now with your setup, if it was good before, and you keep it as a starting point.
The other point is, that whenever you are far out with any parameter. Small changes will have next to no effect.
Your tire example comes to mind.
If this tire would be "way too stiff" (talking in this context vertical stiffness) for your car, because it was designed for another application, I can understand that a tire pressure change in a "sensible" range, has no effect.
If you are 200% out +/- 10% is not going to make a huge difference.
The same goes for damping, if you are way out +5 clicks is not going to help you much.
An your customer may comes to you and says "Your dampers don´t work, my drive feels nothing"
This example is just that, one example, but I have seen something like this.
I´m not saying that this is what happened to your car.
If your customer used a 240 N/mm rear spring, to compensate for an rollsteer issue, where a
80 N/mm spring for this sort of car is much more sensible.
It is hard to go there (80 N/mm), if you don´t know what the problem was to start with.
The moment you have fixed your roll steer problem, and the car develops massive oversteer, changing to a 220 or 210 N/mm spring may does not make much of a difference in this case.
And it is a leap of faith to make a 100-120% change at any one time.
Most people would not try to run half the recomended pressure in a tire, or make such a dramatic change in spring rate.
They can´t believe that they are that far out, and keep playing around with 5% or 10% changes.
What made matters worse, was that the customer would have expirienced before, that making the rear stiffer (spring), has help against the oversteer (which was caused by a massive roll steer issue).
So his first reaction was, let´s try a 300 N/mm spring.
Stiff springs in the rear help against oversteer !!! - was his mantra
The whole setup of that car was compromised, due to the roll steer issue at the rear.
So when this was fixed, we needed to change the rear spring rates, then the damping, and the front spring rates and the damping as well to come back to normal balance and finally more grip overall, and a faster car.
Before we fixed the problem, their was no way, to run a softer setup on that car, because the rollsteer problem was the overrideing factor.
What made it even more difficult to get people to reconsider their setup was the fact, that the car won races, even with the heavly compromised setup.
Now roll/bumsteer is easy to measure, even for a small team, but suspension compliance, rim deflection and torsional stiffness of your bodyshell etc., are not.
If your car in question, was running with rubber/PE bushes in the suspension arms, chances are high, that you had torque steer effects (for better or worse), and with the move to uniballs, they have changed a whole lot more, then they were thinking they do.
Everytime you discover that your car is insensetive to a change, that should be perceptable, you should ask yourself why - there is a story to be told.
If you win a race and you discover that your front ARB is broken and your driver did not feel anything, and the laptime did not change much, chances are, that your ARB is not working as you would expect it to do.
To help you, identify this sorts of problems and to get some basics right, or at least know that things are not as you expect them to be, some hardware in the loop testing, such as Dave`s 4-post rig or an K&C-test rig offer great benefits.
But again, this are just tools, so you also need somebody who know´s how to use them, and
what to look for.
Going onto Dave´s rig gives you not just the data, but also a fresh set of eyes and a different opinion on some aspects.
It´s easy to get traped in your own thoughts and way of thinking at times.
So let´s try to keep an open mind.
Normally there is more to it, then meets the eye.
Use the right tools to fix the real problem.
Sure you can work around every problem, but unless you get the real problem sorted, it´s a quick fix or a band aid, and you will compromise overall/peak performance, to gain relative
performance.
Now you need to know, what the real problem is - and that´s often the hard part.
Here expirience again comes into play.
A single number/data is maybe not of that great benefit, if you have no context.
O.K. you may know, that (as an example) your tire stiffness is 270 N/mm for a given pressure and camber etc., what does it tell you, with your problem??
It would help to know, that maybe 220 N/mm is a more comon or better value for your car.
Now, you can go (if permitted by the rules) and try finding a tire in the size you need, which has this stiffness or is closer,
Quick thought regarding tire data. All the data are of no great use, if you can´t quantify/don´t know your current position relative to the optimum shown in the data.
As a example, Dunlop/Bridgestone or whoever gives me a camber vs. lateral grip graph.
How do I know what my camber in the middle of the corner is.
Please don´t say, are it´s easy I look into my kinematic software.
Do we know what is the deflection of our rim under load? Do we know what is the deflection
of your wishbones? How much movement there is in our wheelbearings? etc. etc.
Sure all of that can be measured, but only a few people realy do.
So for many people (especially in junior categories) tire data are not that useful.
Especially, if it is the only tire permitted to use.
Some tire companies will may give you "dummy/default" data, to make you feel happy and good.
If you can come back to them and point out where you think there are some discrepancies
between what they say and what you see, they will take you serious, and may provide you
with more accurate data.
If not, they will know, that you don´t need better data anyway.
BTW - Dunlop do provide some data for the DTM tires, at least to the DTM teams.
Markus, just out of curiosity - what was the problem with the car. Was the car sliding, or had it a odd balance, what was the limiting factor?
Why could the drive not warm up the tires?
If you don´t mind to share.
) until the final pitstop where a change in tire pressure transformed villeneuves pace and the opposite for schu.
