Technical Analysis: WRC Cars 2017

[TWRC]

Meanwhile the Citroen setup is classic PSA motorsports setup. Cooling radiator on one side, intercooler on the other side.

Classic for Citroën WRCs from the C4 onwards (Xsara had different layout), and classic for Peugeot, who always put the water radiator on the left side and intercooler on the right to try and counterbalance the engine weight. PSA R5s have this classic Peugeot layout as well, but there it was mostly dictated by regulations (intercooler has to be placed where it is on the road car, which is right side on both the 208 and DS3).

[TWRC]

Cracks in Carbon fiber are very hard to discover no? Also much more prone to sharp impact damage.

In my university they have developed special fibers for airplanes that have fluorescent liquid in the middle, so when they fail, they release this fluid, and you can assess the damage by looking at the part with a UV light. Although I know very little about this, it was only mentioned to us during a lecture.
Also, there are some self-healig solutions, like where they make little "globes" filled with glue, so when a crack reaches them and they break, they release this glue and stop or at least delay the further movement of the crack.

[NickRally]

Yes, cracks in carbon fibre parts are more challenging to detect and properly assess, it usually involves ultrasound inspection (more commonly) or CT scans (computerised tomography - more rarely in motorsport due to cost). In motorsport once delamination inside the part is detected, you wouldn't automatically scrap it - if you have the option you might decide to put in a test equipment and apply predetermined load to it and see if the delamination grows, if it doesn't part can be reused depending how critical the application is. If you can't stress it in a lab, then you have to use your experience and judgement. It has to be noted that doing ultrasound inspection "in the field" is possible and should be done regularly on critical carbon fibre components - the teams should carry portable equipment for this.
Also the carbon fibre resin systems include various toughening options (the spheres refered to in the previous post is one of them) to stop cracks in the resin.
I haven't had a chance to look closely at the failed attachment points on the Fiesta's wing, but I wouldn't be surprised if this also involved failed bond between the carbon fibre laminate and a metal insert in it (a hard point in the laminate). It basically can be any one of numerous failure modes that could have occurred.

[krzaki]

Sorry for OT
Does anybody know what technical problems had Latvala?

[Munkvy]

Sorry for OT
Does anybody know what technical problems had Latvala?

From the onboard it looked like gearbox, he was braking for the chicance and the dash said he was still in 6th gear, and should have been in 1 or 2. And then as he pulled round crawling it was still in 4th, so I suspect either the box itself or the controlling functions?

[itix]

From the onboard it looked like gearbox, he was braking for the chicance and the dash said he was still in 6th gear, and should have been in 1 or 2. And then as he pulled round crawling it was still in 4th, so I suspect either the box itself or the controlling functions?

From the onboard you can also see what looks like a jolt in the entire car during breaking at one downshift. Dunno if that's just a coincidence with a hole in the ground or indeed the gearbox but pretty much everything points towards it...

[pantealex]

Sorry for OT
Does anybody know what technical problems had Latvala?

Clutch and flywheel broked, not gearbox, they used same gearbox in sunday.

Reason for no Rally2 to Esapekka Lappi was lost oil pressure in engine.

[noel157]

Clutch and flywheel broked, not gearbox, they used same gearbox in sunday.

Reason for no Rally2 to Esapekka Lappi was lost oil pressure in engine.

Thought it was front right suspension damage rather than oil pressure for Lappi?

[itix]

Clutch and flywheel broked, not gearbox, they used same gearbox in sunday.

Reason for no Rally2 to Esapekka Lappi was lost oil pressure in engine.

Interesting, thanks!

[pantealex]

Thought it was front right suspension damage rather than oil pressure for Lappi?

Suspension was reason for retire but oil pressure problems for no Rally2. (engine was damaged in that suspension failure)