Khamsin Virtual Racecar Challenge 2015

[MadMatt]

Like in F1, keeping the current regs will only make the current strong team even stronger

I have a different opinion (about F1 too): new rules are good for the teams that have better skills and can design a car knowing what they are doing. Weak teams on the contrary take advantages from keeping the rules because the can try to imitate other teams and to experiment different solutions even without completely understand how thy work

This is a valid reason as well, but the thing is the "weak" teams will always try to catch up unless they come up with a great innovation (which never really happens, hence why they are behind in the first place).

What would be great is to have more freedom with the design tho. Your "batmobile" is awesome and I really would like to see more cars like this, or at least having the possibility to do so. Maybe by giving the teams putting the engine at the front some advantage in the laptime simulator?

[CAEdevice]

About the front engined car: actually there isn't any advantage.
There was a specific reason to look for a 50/50 distribution of mass, related to the shape of my front wing/diffuser (that generates a big df).

Anyway front engined (50/50) cars are more elegant and it would be great to have them in the next edition (maybe with some special rules?).

[LVDH]

Like in F1, keeping the current regs will only make the current strong team even stronger

I also disagree. New products / devices always only use small part of their potential performance. With money and time it is easy to increase the performance quite a bit. Then the product gets matured and it gets increasingly hard to improve it.

When that happens it is time for a completely new design. Like seen on the picture, in the beginning it is often worse than the matured design but has more potential and with some time and money thrown at it, it will perform better than the older design.

How does this translate to KVRC or F1?
In F1 a new car will often be worse than the one from the last season because the engineers does not fully understand it and so on. In some seasons the teams have used their old car for the first few races while still testing the new one. If rules would remain constant over a long period of time the top car will achieve pretty much its maximum performance as it reaches the matured stage and it gets very hard and expensive to improve it. Other teams might still be on the steep part (takeoff) of the evolution curve but will catch up over time. After they do that and the performance of the cars gets too close the top teams will complain and ask for new rules. This forces everyone then to create a new design. The top teams will, thanks to better resources, climb the steep part much quicker than the less fortunate teams which were still enjoying having reached the maturity part for the old car but now have to start from scratch. Completely changing the rules does not give the weaker teams better chances in general. It is more a gamble. Most likely a top team will create the best car. Maybe a small team will be lucky. But in general it just hurts the small teams as they have to through everything away and can never really reach the maturity stage.

For KVRC it would be the same. The more pictures of the top cars are released the better the others can catch up. Personally I do not mind that (it helped me as well) and enjoy it. Completely new rules will just create a gamble for one or two races.

[MadMatt]

I understand all this, but I maintain my point. Of course the longer you keep the regs, the smaller will be the gains (unless there is a technology breakout or a big innovation that is found (double deck diffuser, blown diffuser, etc)), as I wrote earlier. This means that in reality the small teams that are behind can never catch up! The last hundreds of seconds are the hardest to earn as in any sport. For sure with some random effects (in motorsport weather, tyre temps, etc), having such small difference between the teams after the regs have been the same for few years means a lower team can get a good result (a "one off", talking about F1), but on the long run, the teams strong teams will always be at the front.

Having new regulations will for sure put everybody on the same page, give everybody a new chance to be at the front but if we really look at how things work, you always end up having the same teams at the top again.

Again, I have nothing against new regulations, I like new challenges But if we think about it, this LMP challenge has only be up for 1 season so it would make sense to do an evolution of the current reg, and maybe have a big change for 2017.

[cdsavage]

Round 4 data:

Code: Select all

                     CL.A   CD.A   COP (m)  Time (s)  Compliant
       Mantium RAY   5.02   1.03   1.567    79.851     Y
         CAEdevice   6.53   1.48   1.593    80.353     N
          Variante   2.29   0.62   1.614    80.375     N
        JJR Racing   4.15   0.99   1.699    80.559     N
      Talno Racing   3.88   1.02   1.771    81.194     Y
          Kineuton   5.04   1.37   1.609    81.342     Y
  Brook Motorsport   1.55   0.95   1.887    83.067     N
       sjns-Racing   2.21   1.25   1.579    83.704     N
Mercury Motorsport   1.40   1.18   1.234    84.417     Y

[/size]
Just a reminder - a version of Virtual Stopwatch is freely available to help guide the setup choice. It's available here: http://www.competition-car-engineering. ... KVtest.htm

For the discussion about 2016, I've created a new thread here: http://www.f1technical.net/forum/viewto ... 14&t=23201

[CAEdevice]

Thanks Chris.

About the data: I was right about the DF/DR ratio

Nobody among the "top teams" had a ratio higher than 5 and (with the exception of Mantium) the "low df" cars has a ratio lower than the "high df" setup.

[hollus]

Guys, listen to Machin. A CdA/ClA vs. lap time scatter plot is very revealing. Nice to follow the competition, by the way.

[variante]

Interesting results for three reasons:
-they give us more indication about the "maximum efficiency" configuration.
-they tell us that efficiency is not the only discriminating factor, like the testrack simulator suggests, as top speed comes into play.
-they have given me a further indication about the awful correspondence between my private tests and the offcial ones (efficiency=7.8 from private tests; pessimistic prediction was 5; actual efficiency is 3.7 )


Impressive performance from Mantium, even though I expected better results from all the top teams. Is someone hiding something, possibly...?

Is Sao Paulo similar to Magny-Cours, anyway?

[cdsavage]

Is Sao Paulo similar to Magny-Cours, anyway?

The final 3 rounds should all be very similar, if we've done our sums right.

[machin]

Yeah, although the two tracks aren't particularly similar to look at and have a difference in average lap speed, the trade-off between drag and downforce is really similar between them... so if you optimise your car using the KVRC Test track that Chris linked above then you'll be spot on the money.

[cdsavage]

A few more images of the top 3:

[machin]

Is someone hiding something, possibly...?

Other than your own front and rear wings?!

[MadMatt]

I will post some comments about the cars seen there:

1) Mantium Ray, good design with use of rounded edges, good for a low drag coefficient, also single element rear wing, although very cambered. Why not 2 smaller elements? Efficiency would be better I guess? Nice junction between the upper deck and diffuser, no gurney flap there, I guess diffuser pumping isn't really a factor there. Would be nice to see a transparent view of the car to see how cooling inlets are shaped as well as air flow path at the front of the car!

2) CAEdevice, as usual tortured design, but even without some of the aero devices, big downforce coefficient! I like the no end-plate rear wing design. Why? Is there a benefit not running end plates in your situation? I still think you should shape your rear view mirrors better, they are not really "aero-mirrors", you would gain quite a bit I think. Also is the throat between the side pod and the front wheel arch not too restrictive for the air flow? I like the side pod shape btw, looks neat!

3) Variante, very slick design, I like it! I see some of the ideas I used for my car there. Cooling inlets, exit. Didn't you try to do anything about the shear drag on the upper deck surface? I like the rounded front wheel arch tho, very neat, as well as the tapering of the engine cover. Did you test if closing/sealing the side of the car (close to the cooling inlet) would improve things? I like the small lip at the rear of the car, behind the wheel. Good attention to detail. Did this improve things over not having the lip or is it just for the look?

[variante]

3) Variante, very slick design, I like it! I see some of the ideas I used for my car there. Cooling inlets, exit. Didn't you try to do anything about the shear drag on the upper deck surface? I like the rounded front wheel arch tho, very neat, as well as the tapering of the engine cover. Did you test if closing/sealing the side of the car (close to the cooling inlet) would improve things? I like the small lip at the rear of the car, behind the wheel. Good attention to detail. Did this improve things over not having the lip or is it just for the look?

Thank you, Matt!
About shear drag: i think we cannot do anything about it in this competition, due to mesh size. What would you do about it, anyway, if there wasn't such mesh issue?
About "closed" bodywork: i've got the impression that such configuration doesn't help with drag... Not sure though as i haven't had time to test it.
About the "lips": i may add them in case i need more front downforce. However i've got no experience with them... Are they efficient? Do they work as vortex generators as well? Would i need VGs in that area?

[CAEdevice]

I will post some comments about the cars seen there:
2) CAEdevice, as usual tortured design, but even without some of the aero devices, big downforce coefficient! I like the no end-plate rear wing design. Why? Is there a benefit not running end plates in your situation? I still think you should shape your rear view mirrors better, they are not really "aero-mirrors", you would gain quite a bit I think. Also is the throat between the side pod and the front wheel arch not too restrictive for the air flow? I like the side pod shape btw, looks neat!

Hi Matt, here my answers.

* no end plate rear wing: no big advantages, only a (very) small reduction of vortices (drag reduced only by 30N...)
* rear view mirror: with a shaped profile I'll reduce drag, but also the slightly high pressure region that reaches to front wheel arches
* narrow space arond the sidepods: it's a balanced solution between the air extraction needs and the attempt to direct air towards the small wing that is placed in front of the rear suspension.
* sidepods: I tried to include the side impact template