WRC Testing

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Originally Posted by macebig

4 speed in a 2.0 liter WRC?Gronholm has some words to say about that...And they are mostly 4 lettered...

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he did fine with 3 gears on that one stage... :P

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.

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Originally Posted by Mirek

Thanks for Your insight. Very interesting but I am not fully convinced :) I admit I don't know the power curve of Xsara but as far as I know Citroën used 6-speed gearbox for late Xsaras and C4 only becaue it was very realiable.

I have seen dyno charts of other cars and some really had very large power bent. I have in front of me very old chart from Fabia WRC 04 (the initial very bad engine with Bosch electronics) and the peak power is near constant in the range 4200-5700 rpm for one of the worst engines in the WRC history with roughly 200 Nm of torque less than the competitors. If I can pick also R5 engine as an example I know that Fiesta R5 has nearly flat power curve all the way from 4500 rpm to the rpm limiter at 7500 rpm.

I tend to disagree about the gearbox design. I don't think that it's a good idea to have more robust gears to cope with the shocks. It's rotating masses whose inertia shall be kept as small as possible to save power.

Anyway I'm no gearbox designer therefore what I write may be a bullshit after all.

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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.

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).

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Originally Posted by Mirek

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).

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That is a very valid question!

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?

Mikkelsen https://www.youtube.com/watch?v=vK2y3ffSuqM

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" :)

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Originally Posted by GravelBen

Very true.

I guess its also fun to watch videos and make wild speculations though. :sailor:

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My bets (before Monte or any other meeting together)
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

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Originally Posted by Mirek

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.
:)

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yeap seems like that. About noise didn't notice something.

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Originally Posted by Mirek

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" :)

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Much louder finally!