Sorry if this topic is a bit random but i was watching the coverage fo the most recent rally new zeland and i noticed something. Every once in a while there seem to be sparks coming from behind the wheel arches of Gronholm's car. It only seems to be him (though i didnt look too closely at the others) but does anyone know what might cause this. I was thinking maybe flint in the rocks on the stage??? does anyone have any thoughts? If you need the episode it can be found here.
http://enormouslysideways.net/WRC2006/

i noticed that also. Here is one scene where its very well visible

Might be small stones thrown at the underbody, might be some part gotten loose and hanging down and dragging on the gravel, it's not really clear to see what's causing those sparks...

I would guess that is a new style of braking mechanism. They probably don't want to talk about it. Similar to when McLaren had pictures taken of their F1 car with only one rear disk glowing in the corners.

speedfreak227

You mean like traction control?

Do they use cheramic brake discs in WRCs? Do those discs "spark" when they heat up during braking?

Quote from speedfreak227 :

I would guess that is a new style of braking mechanism. They probably don't want to talk about it. Similar to when McLaren had pictures taken of their F1 car with only one rear disk glowing in the corners.

That system only allowed for braking one brake disc, a basic form of manual advanced racing ABS type system there's no reason why that'd create sparks. They look like they're probably just some kind of grinding effect from stones hitting something hot, maybe the brake discs.

WARNING: as my english it's not top notch about car/tecnical words i will call "brake pads" the thingy that it's pumped against the disks when braking.

From the movie posted it seems normal sparks from "brake pads"; some compounds produce it some not, you can see it on a peaugeot 106 or on WRCs.
It depends on the brake pads compound, and if you see it also during axceleration mind that Gronholm is known to have almost always left foot on brake ( they made also a joke when he was on peugeot about that, but i dont remember).

Googled "brake pads", yes they are what i intend to say.