Is Downforce the main setup alteration?

[wowf1]

I say this because I race radio controlled cars. The 1:10 scale cars can reach around 45mph with electric motors operating in excess of 40, 000 RPM!
In this hobby, the speeds and scales do not permit us to use downforce to a large degree to change the setup. However, the cars are able to be adjusted in terms of wheelbase, camber, toe-in/out, 'anti-squat', damper stiffness and damper-fluid viscosity, camber-link location, shock-aborber location, weight distribution.

Obviously all of these factors (omitting wheelbase adjustment) are used in F1 and other disciplines. However, all i ever hear on TV or the internet regarding setup alterations is the Downforce! This strikes me as often an inefficient method of setup change. Although i don't pretend to be a Race Engineer, i know plenty concerning the effecttiveness of changing the factors aforementioned. So why don't we hear drivers or teams saying "Yeah we put 0.2 degrees more toe-in on the front an this settled the car during corner-entry"?
All i ever hear is "We put some more wing on the front, which took some understeer away".

Can anyone tell me whether i'm wrong and they do use all those variables i mentioned? Or whether they in fact rarely touch them? thanks, rob

[oz_ferrari]

Yes the teams do all the mechanical set up as you suggested and more, but due to the test rigs in their factories being able to run complete simulations of the races with respect to the mechaincal set up, the teams arrive at the circuit with all the mechanical settings in place. Obviously they can do a little fine tuning at the track with respect to any changes and driver preferences, but more of less this is done one the test rigs these days.

Hope that helped Oz

[oz_ferrari]

...and of course it isn't really possible to simulated the aero set up ahead of time so this is really all the fine tuning that is done at the track. Conventional practice is to get the mechanical set up first then do the final work setting up the car with aero.

[Guest]

ok thanks, that cleared it up! I was aware they used 4+ poster rigs on their cars in order to simulate the grand prix but wasn't aware they were able to place angles etc. on the wheels. Pretty clever when you think about it!!

However, im sure its possible for them to incorporate the aerodynamic simulations into the poster rig results using software in order to pre-determine the exact setup needed for eg. the wet, or different track temps.
Maybe not now, but in a few years?

rob

[oz_ferrari]

Yes, to a degree thats right the 7 post rigs do attempt to simulate the areodynamic laods, but I believe they are just a bit off in simulating accurately the loads. The mechanical set up is mostly based on information from previous years and testing. This information shouldn't really alter much since the are really using the telemetery to map the track and reactions for it. Which I guess shouldn't change too much. The they would fine tune the new car layout to suit, But i'm not sure how exactly they can predict and assess the aero performance round the track. I'm sure they would run simulations but probably they don't know exactly how the new aero set of the car is going to work.
From time to time you hear of teams changing the mechanical set ups at the tracks, but thats normally when the times are really bad and the car keeps falling off the track.
Glad I was able to help Oz

[marcush.]

well,that is the theory...
Anybody who had to master a practise session followed by a qualifying knows that things can get quite hot and you have to compromise....
Inspired guesses and action to follow often give the driver a stop gap fix of a problem ,but if you have more time maybe overnight or for the next
race or year ,the fix of a problem may be executed without too many compromises.
For example : You need more downforce at the rear ,but you have cranked the wing up to the max before.What do you do? Just put on a bigger gurney strip and sacrify topspeed massively or try to balance the car by cuttting of some frontflap...it is all about quick decisions and make them work.
Interestingly enough Ferrari seem to arrive at the tracks with a better
setup than Williams and Mclaren.These often show bouncy behaviour on the first day,so their simulations on springs and dampers seem to correlate not too well with the actual track.
And ferrari? If it is correct that they only have three non adjustable
damper options per weekend,they know a thing or two about mechanical setup.
Looking at the problems Mclaren has to get temperature in their tires
quickly,I feel they do not play around to much with toe in or out ,bump steer ,cambers and things....

[Monstrobolaxa]

But having the data from previous years and the setup parametres that where used for each data print out (and stored) you can use that info to program the post-rigs....either 4 or 7 posts.

Just would like to know how new comers would cope with the problem of not having any info the do a "pre-weekend" setup for a particular track....even doing a private test season...it isn't that easy...for example camber angles....you can take your Monaco setup and try racing it at the Hungaroring.....it might work but the cambers might be all wrong...and the heat won't be distributed in the right way....

[wowf1]

I think i read in Racecar Engineering an article about how smaller teams can compete with larger teams. It said that while big teams may have their own windtunnels etc. smaller teams can use new technology. One of these technologies was software and sensors that recorded downforce as the car was being used/raced.

I think what happens is that you mount the sensors in conjunction with the shock absorbers. The software is windows compatible and the neccessary data about the vehicle weight/shock spring stiffness etc. can be inputted into the software. Then, as the car tests/races, the suspension compression due to downforce can be calculated.

Obviously bumps and cornering hinders this method, but maybe on the straights a more accurate value can be gathered? Or maybe laser sensors can be used as well? I'm just thinking that downforce should be able to be included fairly soon into simulations.

rob

[marcush.]

Well,
that´s why some teams do well at certain tracks or at certain times...
they have found a sweet spot others did not have the luck or knowledge to find....
But honestly ,I´m sure noone tries Formula 1 without having at least one mechanic or engineer with Formula 1 experience ...so things like setup
at different tracks is not really a mystery.
all the simulation cannot make up for experience .And believe me ,a driver with confidence in his and his crews ability will eploit the tyres
(as these are the deciding factor over one lap) to the max.See Schuhmacher M. and Webber for example.
I bet if you are in the ballpark with your balance ,with a tad of understeer
preferably,and don´t try to make the Montecarlo Setup work in Monza ,you should be able to compete at least in qualifying.(this is of course exaggerated..it is more to this ,but a lot of it is psychology)
How else could mr Trulli Know in australiy that the Crash he had before
the first corner(!) did destroy his setup? Other guys do not even tpuch theitr car and the setup went away with ambient temps or whatever....
really this is all about believing in your equipment and there is more to find from your driver and tyres than from a tad of high speed bump.

[Becker4]

what is a post rig? i have not heard that term before.

[marcush.]

It is something like a shaker ,hyraulic rams on wich the car is strapped
the basic version is a 4-Post rig on wich the 4 wheels of the car are put.
the Hydraulic rams ar feed loads into the tyres to simulate actual profiles of race circuits (from data gathered with a car and data recording).
As you modify damper and spring forces you can optimise car setting for the event quite good.
On a seven poster ,the other posts simulate aero loads at different speeds.
As the aero loads compress the springs as speed increases they act effectively as a spring,the underbody aero especially wicked ,as they increase as the car gets closer to the ground dramatically ...

[Reca]

couple of pics of the Dallara 7 post rig:

http://www.dallara.it/sub_page.cfm/editID/172