FIA Rally Working Group: the future of WRC and the rally sport

[Mirek]

There have been discussions on this forum over the years of certain regulations stipulating 'no centre diff'. To me this is engineering nonsense - 'no centre diff' means no four-wheel-drive. It's either locked 1:1 ratio (no way that is what is being used without dreadful tyre wear and horrible handling characteristics), open (what I suspect is truly meant by 'no centre diff'), limited-slip (torque-sensing, viscous etc.), or electronically controlled 'active diff'. I know that even Rally2s have LSDs (correct me if I'm wrong), but not in the centre?

Man, where have you been in past two decades? 90% of all 4WD rally cars produced since 2007 (first one to be Peugeot 207 S2000) have had no center differential. Most of S2000, all R5, all Rally2, all RRC, all WRC 2011. And yes, they do use 1:1 torque split for all the time except when they pull the handbrake for which there is a release clutch.

To me, the perfect 'Rally2+' would be:

[LIST][*]0.5mm increase in restrictor size - only to appease those who say they should have more power, not too much as to increase stresses and service costs/reduce service intervals. Again correct me if I'm wrongly assuming this will not still cause the problems noted. Rally2 would need to be downgraded by 0.5mm to keep that gap.

0,5 mm will add roughly 3% of power. Completely useless modification which nobody will notice. It's just an extra cost with zero benefit.

Reduced suspension travel - this would need to be carefully researched to find out what the sweet spot is to stop the cars appearing to be glued to the road then stipulated in regulations, same would have to be for downgraded Rally2s.

The suspension travel is also a major safety feature. Why do you think we have had by far most deadly accidents with 4WD gr.N cars?

Non-active, LSD centre-diffs - this is not new and expensive technology, my perception is it will increase on-throttle adjustability in slippery circumstances. Again, correct me if I'm way off here.

Welcome to 2005 and the initial S2000 regulations. Do you know what the clever heads in Peugeot found back then and what other teams immediately copied? They found that the mechanical central LSD brings close to zero benefits in handling over having no center diff at all and only consumes power via friction. Nearly all following S2000 cars had no center diff. The R5, Rally2, RRC and WRC 2011 followed suit. The center diff returned only when the active one was allowed again in 2017.

6-speed gearboxes - why were 5-speed boxes introduced in the first place? I heard George Donaldson (99% sure it was him) on a podcast ask that same question, it seems to have been made to no positive affect at all. Surely having more gears gets the best out of your engine anyway? Sequential actuation also is the least road-relevant method of changing gears, just go back to paddle shifters, these boxes were proven and reliable for a long time in the previous two generations of 1.6L World Rally Cars. For Rally2 I'd love to see H-pattern (still relevant in sports cars today) make a return, but this is just a pipe dream. It would at least be another performance differentiator between Rally2 and Rally1/Rally2+.

Sir, you have no idea what you are talking about. Let's start with an explanation what sequential gearbox means. As the name suggests with such gearbox the gears can be changed only one by one in a sequence. It doesn't matter if you do that by paddles or by a stick, by hydraulics, electrics, pneumatics or steel wires.

Six gears over five. First let me tell you that all WRC cars (with the only exception probably being the 2011 ones) have so wide power band that even 5-speed gearbox is enough to keep you driving in the ideal rpms. More gears mean more mass, more innertia, more parts, more complexity, higher price. The 2.0 WRC cars with super high turbo boost could use even 4-speed gearbox (and P307 actually did). The reason for using more gears in a WRC cars is basically only reliability because the steps from one gear to another are smaller and the gear shifting is therefore smoother. Anyway there are no mechanical problems with the current 5-speed geaboxes, so why going for 6-speed? For spectators such change don't matter, far majority of them won't notice anything.