Technical Analysis: WRC Cars 2017

[Mirek]

Nick, while I have nothing to convince You about 17 cars I'm pretty sure that the peak torque of new WRC cars is a lot bellow 5000 rpm (Your graph), I guess 3500-4000 rpm could be right and the torque is definitely reasonably higher than from R5 car (Fabia has even higher torque than Fiesta). The R5 engines are half-stock units while WRC engines are purpose-built units designed from scratch.

Also I don't believe that the cars have only 380 Hp. This number apeared when somebody said that the new engines would have 80 Hp more but the key is that 2016 cars never ever had 300 Hp but much more. Again nothing in my hand but I do believe that the true power of 16 cars was something around 340 Hp (2.0 WRC were even stronger, even vintage cars like Octavia or Corolla WRC had real 320-330 Hp). New cars have 19% larger restrictor which might indicate something around 400 Hp.

[stefanvv]

New cars have 19% larger restrictor which might indicate something around 400 Hp.

Well that's not much of an increase from 380. I believed they can come closer to Group B cars - 450 hp.

[br21]

You can clearly see on MSport base R5 to R5 Evo comparision chart which Mirek upload that torque difference between 4500rpm and 6000rpm is some 100Nm... so it's not flat...
Current R5 cars have over 400Nm of torque so 2017 WRC cars with 4mm bigger restrictors, purpose built engines, more advanced technology, etc have much, much more.

[NickRally]

Mirek, I agree with your numbers about the new WRC cars, the 380hp will be below what they actually have at their disposal and as you said the previous generation of WRC cars would have had more than 320hp (as stated on the net) in the first place (just for reference for the wider audience 320x1.19~380)

[krzaki]

br21 could put dyno plot from fiesta r5 ?
I heard you had few r5 on dyno

[J_n_z]

What is rev. limit for 17 cars? Is it defined by rules?

[Mirek]

I'm not sure but I guess 7500 stays.

[OldF]

It's 8500 rpm.

http://www.fia.com/regulation/category/119

Technical regulations - Article 255A, page 14.

[Mirek]

If they really have rpm limiter at 8500 (I am not sure if they actually use such high rpm at all) it means that the cars actually have shorter gears than 2016 ones - based on the video with speed gun posted in Monte Carlo thread.

[J_n_z]

It seems logical to me... same engine volume, bigger restrictor (more air), so it works optimal at higher revs...