The torque & power of WRC cars, part 2

[OldF]

On the Suzuki’s web site http://www.suzukisport.com/wrc/e/team/machine/spec.html the maximum power is between 4000-4500 rpm. I was wondering could that be true but if you look at the Suzuki’s “low” power curve you can see that the power is slightly above 320 hp between 4000-4500 rpm. This I also noticed myself AFTER I had finished the work on the curves, so maybe there is some truth behind these figures.

The next ones are graphs for group N cars. I put in the same graph the estimate for S2000. All the names with (g) are from the estimate graph above and the names with (dg) are from real dyno graphs so the shapes of these curves are 100% correct.

http://i267.photobucket.com/albums/i...p_N_torque.jpg

The peak of the torque curves for the group N cars are very sharp compared to the stock Evo 9. Probably the stock cars “turbo program” cuts the peak from the torque curve so as the driveability for normal use would be better.

http://i267.photobucket.com/albums/i...rp_N_power.jpg

The shape of the curves for stock Evo 9 and the S2000 are quite close to each other. For the Evo 9 the curve start rising earlier and more rapidly because of the “turbo kick”.

In the next graph I used the grp A Mitsubishi’s curve shapes as a base. I moved the torque curve to 710 Nm @ 3500 rpm to compare it with the torque and power curves of Skoda and to 660 Nm @ 4000 rpm for comparison with the Ford’s curves. The result was about 6-7% lower power which IMO is not so much.

http://i267.photobucket.com/albums/i...Ford_Mitsu.jpg

In this graph I put the graphs of Skoda, Mitsubishi grp A, Mitsubishi grp N (a real dyno graph) and the S2000 estimate. The shape of the “real dyno graph” of a grp N Mitsubishi and the grp A Mitsubishi are IMO very close to each other and the torque curve of the Skoda isn’t either so far away.

http://i267.photobucket.com/albums/i...comparison.jpg


And finally, thanks to katxal and all the others for the S2000 database, I made a torque / power graph for the S2000 cars (VW, Abarth & Peugeot) where both power @ revs and torque @ revs was found in the database. I used the S2000 estimate shape for these so I don’t know how they differ from real ones. They are very close to each other but the torque peak for the Peugeot is @ 6000 rpm and still have the power peak at same revs compared to the other ones which leads to a broader torque band and little more power between approximately revs 4500-6000 rpm.

http://i267.photobucket.com/albums/i...rque_power.jpg

It’s difficult to say what the final truth is for the power of the WRC cars is, but that the peak power would be 300 hp I think has been a joke from nearly the very beginning when it was introduced. As an example are the Mitsubishi WRC figures, that officially has (or had) 540 Nm @ 3500 rpm and 300 hp @ 5500 rpm. It’s hard for me to believe that a WRC car has less torque than a group N car of same make. The area of the restrictor of a WRC car is about 12% bigger than the restrictor of a grp N car and that alone would mean about 12% more power compared to a grp N car, not to mention the bigger turbo boost. The torque and power figures given by the teams I think are the figures for the road boost.

Well, as the guys said that developed the S2000 database “When a hobby becomes a passion..”, this have been my hobby / passion lately.

[dimviii]

a dyno sheet from a friends evo 6 gr A was at 530Nm at3700 and 320 bhp at 4800 @1,9 bar. with turboelf gas

[Steve Boyd]

Very pretty graphs - but what they don't show is that for the Gp A Mitsubishi 710Nm @ 3500rpm equates to 349HP (354PS) & for the Ford 660Nm @ 4000rpm equates to 370HP (376PS). All the WRC manufacturers are guilty of this little decption. They quote a power figure near the maximum usable rpm & everyone assumes that this is the maximum power because the figures look like powerful road car numbers. What they carefully hide is the huge mid-range torque gives them more power at 3500 - 4000 rpm than they have at 5500 - 6000rpm, and well in excess of the notional 300HP FIA power limit. The same calculation on Suzuki's torque figures gives 290HP (294PS) @ 3500 rpm showing they've got a lot of catching up to do.