[KVRC] Khamsin Virtual Racecar Challenge 2016

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machin
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Re: Khamsin Virtual Racecar Challenge 2016

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variante wrote:Some articles like K3.5 could be completely dropped. Others could be simplified or reworded.
In essence I think your idea is good (less rules = easier compliance check = less work for Chris/Julien)... but it would be good to hear which rules you would re-write and how you would re-write them if you already have some ideas?
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LVDH
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Re: Khamsin Virtual Racecar Challenge 2016

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I think that sounds very reasonable. Maybe you could give the opportunity to withdraw a car for what ever reason.

About the front suspension visibility:
I never liked designing that part too much but think it was a great challenge and would like to keep it.
Most parts are designed for great down force or efficiency. These parts are different as you mostly try to keep the detrimental effects as small as possible. And in real cars almost the every part is like this. I guess only in F1 they are crazy enough to go for the strangest uprights possible just to gain that small aero advantage.

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RicME85
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Joined: 09 Feb 2012, 13:11
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Re: Khamsin Virtual Racecar Challenge 2016

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I hope we can get the rules in place soon, I'm itching to get to work on my 2016 challenger.

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variante
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Joined: 09 Apr 2012, 11:36
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Re: Khamsin Virtual Racecar Challenge 2016

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machin wrote:...you specifically asked for your team to be withdrawn...
Sounds reasonable to me as well, in those terms.

I also agree with LVDH. And, from my point of view, we should either keep suspensions rule pretty much as it is, or drop it completely and go for the "Red Bull X1" style.
machin wrote:but it would be good to hear which rules you would re-write and how you would re-write them if you already have some ideas?
This takes time... I'll do it as soon as possible

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CAEdevice
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Re: Khamsin Virtual Racecar Challenge 2016

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machin wrote:
CAEdevice wrote:
variante wrote:It not always true that someone who decides not to submit wants the old car to race anyway. For example, if i get no time to work on an updated version of my car (and i'm not so interested in earning points at any cost), i don't like the idea ...
Well, my interpretation is that I would have the additional choice of re-run a previous submitted car or a new one. No choice, no race.
Personally I would suggest the opposite: the previous car would be used unless you submit a new car or you specifically asked for your team to be withdrawn... that means if you accidentally miss a submission (maybe you are busy or just on holiday) then you don't lose out too much on the championship, and we are still likely to end up with big "grids" by the end of the season which looks better publically. As in real life: small grids don't do the championship any favours.
Ok, I like this version.

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CAEdevice
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Re: Khamsin Virtual Racecar Challenge 2016

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I have a question for machin and a suggestion for the next year.

I'm writing an article about KVRC2015 and I would need the car data: from the "test track" page I can only get a few numbers, but I can't find the total power and how the kers power is distribuited (uniformly?).

During next year it would be better do dedicate a page on the official website to the technical description of the mechanics of the car, I also suggest to consider that data as a part of the rulebook, to be sure they will not change during the season.

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machin
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Re: Khamsin Virtual Racecar Challenge 2016

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We actually did change the power half way through last season:

For the high downforce races we had 600bhp +160bhp KERS. For the mid/low downforce races we had 540bhp+KERS. This was to promote a more efficient design in the later races. In both cases all power was distributed to the rear wheels.

For next season we're likely to have a similar set-up although I am working on some adjustments such as a variable tyre wear rate model and a fuel allowance per lap, just like the real LMP1 class.

At the end of the day all these parameters do is affect the trade off between drag and downforce at any particular track...(the lines of "constant lap time" if you plot the test track results on a graph of drag vs downforce).

Rest assured that once we've started on a particular "block" of tracks (either high downforce, or low drag, etc, which have each been carefully selected so they have a very similar aero trade-off) I won't play with any parameters which affect the trade-off between drag and downforce without a big warning, and most likely no change will be made at all.

EDIT: good ide though, a page with information about the mechanical aspect of the car would be interesting. I'll put this together.

For example, I bet you guys didn't know that the cars have active suspension so that the attitude of the car (pitch, roll, heave) doesn't change during acceleration, braking or cornering so that the aero coefficients achieved in testing are the ones that apply throughout the entire lap ( There is no change in ride height or inclination during braking, for example), ;-)
Last edited by machin on 14 Dec 2015, 21:39, edited 1 time in total.
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CAEdevice
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Re: Khamsin Virtual Racecar Challenge 2016

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machin wrote:We actually did change the power half way through last season:
For the high downforce races we had 600bhp +160bhp KERS. For the mid/low downforce races we had 540bhp+KERS. This was to promote a more efficient design in the later races. In both cases all power was distributed to the rear wheels.
machin wrote:Rest assured that once we've started on a particular "block" of tracks (either high downforce, or low drag, etc, which have each been carefully selected so they have a very similar aero trade-off) I won't play with any parameters which affect the trade-off between drag and downforce without a big warning, and most likely not at all.
I remember something like this, but I was not sure. I think that the total power should be the same for all the season: some choices, for example the high nose or the "full open" sidepods, have impact on efficiency, but can't be modified during the season, without a very heavy new development stage.
machin wrote:For next season we're likely to have a similar set-up although I am working on some adjustments such as a variable tyre wear rate model and a fuel allowance per lap, just like the real LMP1 class.

At the end of the day all these parameters do is affect the trade off between drag and downforce at any particular track...(the lines of "constant lap time" if you plot the test track results on a graph of drag vs downforce).
Wonderful, I like very much this perspective.

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machin
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Re: Khamsin Virtual Racecar Challenge 2016

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CAEdevice wrote:I think that the total power should be the same for all the season: some choices, for example the high nose or the "full open" sidepods, have impact on efficiency, but can't be modified during the season, without a very heavy new development stage.
Remember power is just one aspect which affects the aero-coefficient trade-off: Track layout is the most influential factor, but tyre characteristics, mass, power, CG position (etc. etc) all have a smaller impact...

I'll give you the background as to why we altered the power: We thought about running a round at Le Mans, but decided that would result in the downforce levels being too low, so we went with slightly more "conventional" tracks for the second half of the season, but with a 10% power reduction to get the sort of aero trade-off we wanted, the power didn't make a huge change, but was in the right direction. In hind-sight we could've run at Le Mans but increased the power available to get the trade-off we wanted...

I think the most important thing is that we make the test tracks for all rounds available at the beginning of the season; with all of the parameters set (even if they do vary between the two different types of tracks), so that you can plan your car for the whole season. That should be easy in 2016 as I don't think that anything major will be changing.... We couldn't really do it early in 2015 because we weren't sure how good the cars were going to be!
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CAEdevice
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Re: Khamsin Virtual Racecar Challenge 2016

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Ok, to have all the test track and the power levels is not my preferred solution (I would choose a costant power), but it is much more acceptable.

About the tracks: of I had to decide, I'll choose 1 extreme df track (Monaco), one extreme low df (Monza), and as many more "efficiency" tracks as possible. "Efficiency" races allow very different solutions for geometry and strategy at the same time.

With "efficiency races" I mean reces where the winner is the car with the best dr/df ratio.

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machin
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Re: Khamsin Virtual Racecar Challenge 2016

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CAEdevice wrote:Ok, to have all the test track and the power levels is not my preferred solution (I would choose a costant power), but it is much more acceptable.
I think I'm not being clear... if we had three tracks ("Track A", "Track B", and "Track C"), and the car had 600bhp at each the gradient of the "lines of equal lap time" on a graph of downforce:drag on those tracks might be 2:1, 3.5:1 and 10:1 i.e. Tracks A and B are fairly similar and Track C requires a really efficient design. However, we wanted a round which had a 4:1 efficiency ratio requirement. We had two options: Either we keep modelling new tracks until we find one which has a 4:1 ratio, or we could take Track B and adjust the car's power until we hit the 4:1 ratio we were looking for. The end result for the competitor is the same: The competitor has to design a car with a 4:1 efficiency Ratio requirement, but it saved a whole load of time because modifying the car's power output is a much quicker task than modelling lots more tracks....

Personally I would say the track selection was pretty good in 2015. I think it was good to only have two different "types" of tracks, and also not to jump from one type to the other as it meant that people weren't constantly having to adjust their design for different characteristics. The only thing I would change is not to do one track twice. Actually I'm thinking of modelling the Pikes Peak Hillclimb course as an alternative "high downforce track" which I had the good fortune to drive up in 2010. That was before it was all tarmacked, but I can adjust for that.

This again is another instance where it is good to be able to adjust the car's "mechanical" parameters: When I model the Pikes Peak Track I might find that the "lines of equal lap time" are a bit too different from say Monaco. To make it easier for competitors to "dial-in" their car we want all the "high downforce" rounds to have a similar "Efficieny Requirement". In order to do that I can adjust the power (and maybe other parameters, such as the tyres). That means you (the competitors) will still only need two test tracks (a "High Downforce" and a "Medium Downforce" track) like we had this year, and it will mean that a car which "works well" at Monaco will work equally as well at Pikes Peak... There is no need for each competitor to do further analysis to figure out what the best set-up is; obviously people will need to develop their car if they want to move up the grid, but at least the "goal posts" won't be moving...
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machin
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Re: Khamsin Virtual Racecar Challenge 2016

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I suppose one question is whether that approach (adjusting parameters to achieve a specific performance) is "realistic", and I would say that it is: for example F1 uses different tyre compounds at different tracks, Indycar has power caps at speedways, LMP1 has different fuel allowances at each track....

I would propose that we insert the two graphs of drag:downforce showing lines of equal laptime representing the two tyoes of track we visit into the rules, (i.e. So they're "fixed" and transparent for all to see), but then the way we achieve those graphs is left up to us: either through track selection, parameter changes, or a combination of the two.
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CAEdevice
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Re: Khamsin Virtual Racecar Challenge 2016

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Yes, the most important thing is that the "tuning", for all the tracks, will be clear for all before the first race. To change the max power may be not the most elegant way to do it, but it is ok for me. Thank you for the explanation.

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LVDH
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Re: Khamsin Virtual Racecar Challenge 2016

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And full points for every race!

Any idea when the new rules will be released?

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CAEdevice
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Re: Khamsin Virtual Racecar Challenge 2016

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LVDH wrote:And full points for every race!

Any idea when the new rules will be released?
Full points?
I'm wondering too when the rules will be published, I've not been working on the car, but I'll have couple of surprises related to KVRC in the next weeks.