he did fine with 3 gears on that one stage... :PQuote:
Originally Posted by macebig
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he did fine with 3 gears on that one stage... :PQuote:
Originally Posted by macebig
With low number of gears gearboxes, or gearboxes with long gears important problem is that it's not easy to choose proper gear in some conditions plus also main problem is downshifting - it's easy to lock the wheels (or at least make the car unstable), and it affects your driving, confidence and also adds additional shock for drivetrain (which can make it got damaged easier). In case of R5 you can see it a little bit in case of Fabia, where you have long gears and on twisty stages it's not that easy to choose proper gear, I mean if you're not in ideal gear then you feel you loose a lot, it's different in short ratio boxes, when you're not in ideal gear you feel if for split second and then it goes OK again. And while downshifting you need to keep that in mind also.
Its off cource important to have rotating inertia low to keep power loss at minimum, but I only wrote about the theory behind "bigger and stronger gears" if you like.Quote:
Originally Posted by Mirek
Anyway, Peugeots plan failed, that we can agree on.
The "problem" for designers/engineers in rallying, is that it is so many parameter, and that a "lap" will never be perfect, because the drivers will always have some variation in grip etc.
So as you say, with to few ratios you will "always" be to high or to low.
And a thing that was very important with that - as many times - what works on the drawing board/on the computer, might not always work in real life - especially in rallying.
We have seen this many times.
- Peugeot: 4 gear gearbox is one example.
- Peugeot: engineer made theoretically perfect mapping of active diff in 2004 the same. I remeber in NZ, the car violently transferring power back/forth mid corner. I was amazed by how Grönholm could keep that car on the road whit that happening. (He was prob robbed of a title or two by that car)
- Subaru/Prodrive: 2005-onwards hiring racing engineers. Lots of things happened. Wings fell of because mountings was too light. Engine drowned in water crossing in Argentina. Etc etc.
But "problem" with gearboxes mostly went away when they went from human shifted dog boxes, to computer controlled sequential ones. So this is one time when a more expensive parts made the running cost lower.
Any 10 year old can change gear in a modern WRC car, they wouldnt fare quite so well in a car with a "manual" dog box. :)
I wonder which of these new cars with their aerodynamic front ends is going to eat snow the best. We have seen already in the Monte testing of M-Sport that there might be issues with overheating. Could be a similar story like that one with drowned Subaru engines (rather in Sweden).
That is a very valid question!Quote:
Originally Posted by Mirek
Not only in Monte, but also in Sweden.
Ford definetly have potential to eat som snow/clog up the air intake.
Longer/bigger splitter, together with canards, will also catch snow on the snow banks in Sweden.
Will be very interesting to follow.
Another point on aerodynamics:
Citroën C3 seams to have clearly the biggest frontal area (see it on the "small" fender flarings). Will be intersting to see if this potentially higher drag/or sacrifice in downforce will be noticable?
Different sound of the Fabia, anyone?
By the way from the background talk it seems that Mikkelsen went off twice during the test but the talk is cut so I am not totally sure that it was said about him. For sure there is the broken traffic sign visible.
Plus there is some rather funny background comment from some locals: "What's his name? - Mikkelsen, some Norwegian" :)
My bets (before Monte or any other meeting together)Quote:
Originally Posted by GravelBen
Monte 1.Meeke, Citroen
Sweden 1.Ogier, Ford
Mexico 1.Neuville, Hyundai
Corsica 1.not Toyota, probably Ogier or Meeke
Champion Ogier
Team Champion Hyundai
yeap seems like that. About noise didn't notice something.Quote:
Originally Posted by Mirek
Much louder finally!Quote:
Originally Posted by Mirek
This is a more complex subject as far as I know. Look at LMP1 cars in recent times, there was a shift to more vertical front edges while also trying to control how air moves through and around the car. It's true this was also cause by regulations (the open slits on top or on the side of the wheel well) but it showed that having a more "blunt" attack angle is not necessarily worse, especially if you can control how the air moves around or over the surfaces. The dive planes (the small wings on the front bumper) play a big role here as well.Quote:
Originally Posted by Lundefaret
Overall I guess it's more about the shape of the whole package and low pressure areas behind the car, not just surface area.
There is a lot of analysis on this subject on http://mulsannescorner.com/ website and facebook group.
Ratio wise it seems the i20 has a very short change between 2&3 or 1&2, as Sordo boosts straight on the rev limiter out of the hair pin corners, seems bang, instant whack of power in the videos.Quote:
Originally Posted by Lundefaret
It perhaps sounds a bit louder and raspier but it could just be the atmospheric conditions.Quote:
Originally Posted by Mirek
Unless you know they've changed the exhaust system?
You miss my point, or (more likely) my english is the problem...Quote:
Originally Posted by Mirek
I wanted to comment your thought, that low torque is the thing that prevents car going sideways... tires slide.
But it is not, power is the thing that makes tires slide, because at same wheel rev. speed and increased power the torque on the wheel is bigger ie. more force to transfer to the ground...
I agree with your writing, but things like piston friction loses, torque curve shape, driveability of engine and transmition... all are caracteristics of power genereting and power transfer, that needs to be optimised as you said.
Still power is the thing that moves things and torque is just a component of it.
You are right with that, sorry for misunderstanding.
Still while what You say it's true it doesn't mean that the car will go sideways because of the peak power. I take a slighly extreme example of S2000 car with atmospheric engine. They had enouh power for sliding at the top rpm. Sliding-wise S2000 cars had a typical behavior - nearly no drifting in lower speeds but sometimes violent slides at the exits of the corners even in very high speeds (for example when some dirt was present). In the end this fraction of a second long power slides can't by called driving sideways (my opinion) even though it was spectacular in the fast sections.
The new WRC are slightly similar even though they have double the torque to S2000. I can see similar pattern especially with the i20 on the videos but only in low speeds (presumably because S2000 has very low aerodynamic downforce). Very calm and clean with just a short powerslide at the peak power (Monte Carlo sessions).
Anyway for me the main reason why not to drift through the hairpins and sharp corners is the center active differential. The 16 cars with no center diff suffered from massive natural understeering and the drivers had to throw them around in drifts to turn. Sometimes it went to near ridiculously spectacular back-first driving. I remember very well the first impressions from Sweden 2011 and the discussion here on the forum.
Even on tarmac '17 cars will go more sideways than current ones. In case you've miss them, he're some nice samples of the big slides ahead of us!Quote:
Originally Posted by Mirek
https://www.youtube.com/watch?v=dMJhwbQCy78
https://www.youtube.com/watch?v=lAeAe3yg6-k
https://www.youtube.com/watch?v=TqItOuzIElE
https://www.youtube.com/watch?v=lkVFd9RQnO0
Slowson gave a good example with the hairpin @ 1:16 of his video link. This is what is hardly possible with 2016 car. Similar situation with Citroën here at 0:45: https://youtu.be/RumejYWCldc?t=45
By the way I have never said that 2017 can't go more sideways. Of course they can but why? The point is that while 2016 cars had to go sideways in certain situations the 2017 cars don't need so. That's the sole reason of active center diff and new aero package existence and I really don't see why do You argue about that.
Latvala
https://youtu.be/BPJ_RXiSzhU
Toyota diff mapping evolution is interesting to me (or maybe I see to much test videos).
First little understeer:
https://www.youtube.com/watch?v=j_9VsvaUczA
After few days some fast oversteer (as Mirek mentioned)
https://www.youtube.com/watch?v=Bl_szvXqNTw
Than some balanced handling but little corrections was still needed
https://www.youtube.com/watch?v=Qd6UsRY5bZ8
And finally good stable balancend (almost 2009 like) handling
https://www.youtube.com/watch?v=Bewf21IjaJU
I think you´ve seen too much test vids.
How on earth can you tell from these different conditions? We can see surfaces is not same on the vids, and also two drivers, so for me I wouldn´t make any conclusions whatsoever on differences on handling of the car. Unless I was at sight, talking to the drivers or was expert on suspension working for the team etz.
For sure we can figure out they have tested settings. But making conclusions out of it, no!
That´s my opinion. Don´t take it hard J_n_z ...
Michelin video with Latvala
https://youtu.be/Gpyy1SpxlrU
Verticality has nothing to do with frontal area, that is, as you say your selves, in an effort to direct air flow.Quote:
Originally Posted by seb_sh
Moder LMP1 cars have as small a frontal area as the rules will allow.
If you ask Adrian Newey this is his first objective when designing a F1 car.
For a rally car, a lot of the parameters are given, because you start with a production car body, and you have an 1875mm width limit.
So, the smaller frontal area the road car body has, the less drag you can achieve (also a bit dependant on general body shape), and the more liberties you can take to design the aerodynamic "helpers."
So if you look at the Toyota it is quite a narrow car, you can see this on the width of the fender "boxes." You also see this on the Polo.
Fiesta seems a little bit wider, so also the i20, and the C3 the widest.
In regards to the C3 I think they have worked a lot on drag, on top of downforce, because they started with a bigger frontal area. And i suspect this is why they went in the direction of "normal" fender flares, vs the boxes.
They have also used a lot of time perfecting the air flow around and in the fender flares. They have "blown" the fender openings, very visual in the front with air coming in from behind the head lights.
In regards to the Toyota, they have gone max out towards downforce.
Ford and Hyundai is in the direction of the Toyota.
Will be very interesting if it will be a real performance difference. If it is any, this will be most evident in medium to long corners, in medium to high speed (100-200 kph), with an increasing factor depending on how straight you can drive the car.
You are right of course about frontal area. If a car needs to punch a bigger hole through the air it will have more drag. I was just pointing out that it's not the only factor. You also mention some interesting stuff, I didn't study the aero bits as closely but one thing that I also noticed is that Toyota has probably the most aggressive aero package, I mean they are trying to get the most downforce, especially from the underbody and diffuser. After that come Hyundai and Ford and seem to have about equal amount of aero elements then Citroen with slightly less aggressive parts. But like I said I'm no expert and haven't looked at this in detail. Oh and how about the VW that was also not so aggressive, I guess it would be at about Citroen level, no?Quote:
Originally Posted by Lundefaret
C3 production car is 1470 mm high 40 mm lower than Yaris... wheel area width is equal, so I can imagine, that C3 cross section is actually relatively small.
C3 2017Quote:
Originally Posted by J_n_z
Height: 1470 mm
Width: 1745mm
Wheel arch width: 65 mm pr side
Yaris (2016, I think the 2017 will be quite similar?)
Height: 1510 mm
Width: 1695 mm
Wheel arch width: 90 mm pr side (the difference is a bit bigger because the Citroën is squarer in its shape)
plenty photos from c3 wrc,some suspension photos too
http://elevageduchateau.chez-alice.f...RC_15dec2016/#
http://elevageduchateau.chez-alice.f...WRC_14dec2016/
Some interesting stuff here but maybe it should be in the Technical Analysis thread ... ;)
4 years of VW rush : https://www.youtube.com/watch?v=ZnpfYEN3LjE
Merry christmas.
Docu the other day on Elfyn Evans Season Review showed him doing plenty of testing of the new 2017 Fiesta.
He must be getting a drive with one at some point with MSport/DMack...
doesnt mean a thing if you have a contract with Wilson, Camilli has also done a lot of testing with the new car but now we know that he wont even drive with it.
Looks like it does mean something... Evans is on the seeded Monte start list. :)Quote:
Originally Posted by EstWRC
Abarth test https://www.youtube.com/watch?v=zAQ95NNk5MA
https://www.youtube.com/watch?v=A8ZCoFet4iw Hyundai two weeks ago under a tiny snowfall
ps. and one mixed clip uploaded two days ago :confused: https://www.youtube.com/watch?v=mWSfPBk2pXg
It is a mazda miata :)Quote:
Originally Posted by EstWRC
Skickat från min iPhone med Tapatalk
Meeke Sweden: https://www.youtube.com/watch?v=yqWDoh4LkKw
Now if they only had some proper narrow tyres to use all that power!Quote:
Originally Posted by dimviii