Technical Analysis: WRC Cars 2017

[Mrpengski]

Quick newbie questions.....

1) Is the intake on the roof for driver ventilation?
2) Does the driver consult with an engineer prior to shock tuning between stages?
3) Is there a development freeze on chassis, body, and/or engine to contain costs? I think I heard three years. What can the teams do during that time in terms of development?
4) These cars costs $900,000 US compared to a NASCAR at $250,000 US. NASCAR struggles for sponsorships and TV packages to keep teams alive. How does the WRC do it?...Maybe not a purely technological questions, but indirectly related.

Thank you

Hi Revman,

1) Yes, roof vent (bit of a misnomer) for cockpit ventilation.
2) Teams run a pre-event test in representative terrain/surface before each rally, which is where the baseline setup of the cars are determined. Throughout the weekend, the crew (driver/codriver) can and do constantly make adjustments to the dampers, ride height, etc. as the conditions change. The race team/engineers are all involved in this together of course.
3) "Freeze" might be too strong a word here. Yes, the regulation which came into effect this year stays until (at least) 2019. Teams must homologate certain parts of engine, suspension, chassis, hydraulics and bodywork, and they are indeed "frozen". We are allowed a number of "jokers" to spend, i.e. make modifications to homologated parts. Some parts are homologated as options, so different types can be introduced throughout the year. Other parts are completely free in terms of development. So it's not a development war, but not completely restricted either.
4) $900k is a very conservative number I myself still can't fully make sense of the economic side of things, I just hope every team has deep pockets and everyone can race as long as they want!

Nick, speaking of gurneys, have you noticed the massive unruly ones on this year's cars? They must now meet the ECE pedestrian safety requirement of R2.5 min, so on a parallel surface edge that's 5mm thickness...

[NickRally]

Hi Revman,

1) Yes, roof vent (bit of a misnomer) for cockpit ventilation.
2) Teams run a pre-event test in representative terrain/surface before each rally, which is where the baseline setup of the cars are determined. Throughout the weekend, the crew (driver/codriver) can and do constantly make adjustments to the dampers, ride height, etc. as the conditions change. The race team/engineers are all involved in this together of course.
3) "Freeze" might be too strong a word here. Yes, the regulation which came into effect this year stays until (at least) 2019. Teams must homologate certain parts of engine, suspension, chassis, hydraulics and bodywork, and they are indeed "frozen". We are allowed a number of "jokers" to spend, i.e. make modifications to homologated parts. Some parts are homologated as options, so different types can be introduced throughout the year. Other parts are completely free in terms of development. So it's not a development war, but not completely restricted either.
4) $900k is a very conservative number I myself still can't fully make sense of the economic side of things, I just hope every team has deep pockets and everyone can race as long as they want!

Nick, speaking of gurneys, have you noticed the massive unruly ones on this year's cars? They must now meet the ECE pedestrian safety requirement of R2.5 min, so on a parallel surface edge that's 5mm thickness...

Once again very helpful insight. Also very interesting what you are saying about the gurneys - should we assume the same applies to the wing trailing edges? And even more to the point, presumably the edges can't be left square, but must be radiused with R2.5? This will straighten the hair of any F1 aerodynamicist

And one more question - you are saying "Throughout the weekend, the crew (driver/codriver) can and do constantly make adjustments to the dampers, ride height, etc." - how do they adjust the ride height? This must involve some fairly hard work assuming you are not allowed to do it from the cockpit?

[Mirek]

I don't know if it's same with the latest WRC cars but with R5 You can move the lower spring platform.

Teams must homologate certain parts of engine, suspension, chassis, hydraulics and bodywork, and they are indeed "frozen".

Is the damper internal structure still free?

[NickRally]

I don't know if it's same with the latest WRC cars but with R5 You can move the lower spring platform.

Thanks Mirek, so hard working it is then.

[Revman]

Hi Revman,

1) Yes, roof vent (bit of a misnomer) for cockpit ventilation.
2) Teams run a pre-event test in representative terrain/surface before each rally, which is where the baseline setup of the cars are determined. Throughout the weekend, the crew (driver/codriver) can and do constantly make adjustments to the dampers, ride height, etc. as the conditions change. The race team/engineers are all involved in this together of course.
3) "Freeze" might be too strong a word here. Yes, the regulation which came into effect this year stays until (at least) 2019. Teams must homologate certain parts of engine, suspension, chassis, hydraulics and bodywork, and they are indeed "frozen". We are allowed a number of "jokers" to spend, i.e. make modifications to homologated parts. Some parts are homologated as options, so different types can be introduced throughout the year. Other parts are completely free in terms of development. So it's not a development war, but not completely restricted either.
4) $900k is a very conservative number I myself still can't fully make sense of the economic side of things, I just hope every team has deep pockets and everyone can race as long as they want!

Nick, speaking of gurneys, have you noticed the massive unruly ones on this year's cars? They must now meet the ECE pedestrian safety requirement of R2.5 min, so on a parallel surface edge that's 5mm thickness...

Thank you so much! What a fabulous sport!

[GigiGalliNo1]

I'm enjoying this thread, very professional and serious for this forum. Thank you.

[AMSS]

[QUOTE=Mirek;1145988]I don't know if it's same with the latest WRC cars but with R5 You can move the lower spring platform.

Mrpengski surely knows better how it is today but at least on previous WRC generation you could adjust the ride hight hydraulically from the boot/engine compartment limited times via a pressure ackumulator(once pressure was used than back to mechanic adjustment)
Same thing damper internals were completely free.
But it would be interesting to know if there are changes to the rules in current WRC generation?

[sonnybobiche]

MrPengski, can you clarify for us whether there were some last minute regulation changes to ban those sweet two-element wing mirrors that Toyota were using? I noticed they were used in testing and were present on the launch car but were gone by Monte, replaced with a much simpler design. Also read an interview with Makkinen where he alluded to some last minute aero reg changes that pissed him off and cost like $60,000 to redesign around them, but he didn't specify what it was.

[Mrpengski]

Damper internals - no change from previous regulation as far as I know.

What could have happened with the mirrors (I don't know for certain) is that the FIA said not allowed, end of story. Simply put, a mirror is a device to give rearward visibility, and technically is not allowed to be or do anything else. I think it's a very different approach compared to F1 (definitely) and other series (probably), and we can push the rules a bit but not too much.

TM could be talking about the side impact regulation. As you may have noticed, most team's first test car was without the extra protection. The problem is, by adding some ~100mm to the door, you need to redesign pretty much the whole aero package. To start, the rear fender/door definitely has to change, then you must consider its effect on the rear wing and try to balance that with new front aero. Or it could be the rear wing, you can see the original version on their first test car (shall we say, "Ford style") versus the current one.

[dimviii]

https://www.youtube.com/watch?v=ftE2S509__E