Ford Fiesta RS WRC

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Originally Posted by FVS

Latest Focus WRC 343hp 870Nm torque, Fiesta almost same amount of HP but around 300Nm less torque. PS. very reliable source.

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Well, I don’t know what to believe anymore.

Is this a domestic or a works car?

As far as I know, power (in an engine) can’t be measured directly, only calculated with the formula P = T * angular velocity (correct me if I’m wrong).

Assuming the peak torque (870 Nm) is around 3000 rpm, the power at that stage would be P = 870 Nm * 3000 rpm * 0,0001424 = 372 PS.

Explanations needed.

If the Fiesta has about 300 Nm less torque, that would mean about 570 Nm. This is IMO quite high value for 1600 cc engine with 1,5 bar boost. 570 Nm is what an EVO 9 has with 32 mm restrictor and higher boost.

The peak torque is lower. I don't know about Focus but in Fabia WRC it was around 2700 rpm I think and that was pretty bad engine.

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Originally Posted by OldF

Is this a domestic or a works car?

As far as I know, power (in an engine) can’t be measured directly, only calculated with the formula P = T * angular velocity (correct me if I’m wrong).

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That's why you connect a dynomometer up to either the crankshaft or flywheel (Engine Dyno) or a set of rollers (Chassis Dyno) and read off the figures from a computer.

kW = Nm*rpm / 9549 (as a rough guide).

343bhp out of a Focus WRC sounds entirely plausible. The RS500 Focus gets 353bhp without the restrictor plates.

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Originally Posted by OldF

Well, I don’t know what to believe anymore.

Is this a domestic or a works car?

As far as I know, power (in an engine) can’t be measured directly, only calculated with the formula P = T * angular velocity (correct me if I’m wrong).

Assuming the peak torque (870 Nm) is around 3000 rpm, the power at that stage would be P = 870 Nm * 3000 rpm * 0,0001424 = 372 PS.

Explanations needed.

If the Fiesta has about 300 Nm less torque, that would mean about 570 Nm. This is IMO quite high value for 1600 cc engine with 1,5 bar boost. 570 Nm is what an EVO 9 has with 32 mm restrictor and higher boost.

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The restrictor is 33mm and the boost is restricted to 2,5 bar boost.
All formulas are nice and indeed correct if you know what you are searching for, you are correct that the formula is as calculated for angular velocity, but what it doesn`t take into account for is that there are in this case 4 cylinders on a crankshaft working all with different ignition times etc. therefore you would have to calculate all of them together and divide it in a complicated way( basically what a good engine dyno does) and therefore it is not as easy as it would seem based from a formula.

And the data is for latest spec. works car!

There are some Interesting and positive comments from Jari-Matti in this weeks Motoring News regarding the Fiesta WRC, iirc he said that it had more power than the Focus, the centre of gravity felt improved over the Focus, it had fantastic turn in, very agile and on tarmac especially.. a big improvement with the rear of the car (where the focus 'dragged' the rear) and that they now have the extra 6th cog they had been crying out for.

I would be interested to know if his comments on power are based on perception or actual figures, the extra cog itself will improve acceleration a little and maybe they have found some more power from more accurate fuelling via the DI (Direct Injection) but could it be that these 1.6T engines possibly having greater bhp than torque by ratio compared to the old 2.0T means that they now use the full RPM range instead of short shifting and driving to the peak torque figures they used to previously which should in my mind at least would make it feel faster?

Thoughts?

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Originally Posted by Zico

but could it be that these 1.6T engines possibly having greater bhp than torque by ratio compared to the old 2.0T means they now use the full RPM range instead of short shifting and driving to the peak torque figures they used to previously which should in my mind at least would make it feel faster?

Thoughts?

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If they manage to climb through revs, is achievable,despite less cc.

Christian Loriaux said to MTV3 that he thinks that in slow rallies like Cyprus Fiesta may be faster than Focus was. In fast rallies like Finland or Sweden Fiesta is most likely to be little bit slower.

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Originally Posted by vkangas

Christian Loriaux said to MTV3 that he thinks that in slow rallies like Cyprus Fiesta may be faster than Focus was. In fast rallies like Finland or Sweden Fiesta is most likely to be little bit slower.

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Wait exactly the opposite imho

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Originally Posted by dimviii

Wait exactly the opposite imho

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I'd stick with Loriaux. :) Generally high speed performance is worse with lower peak power. Shorter car with the lower center of gravity on the other hand is more agile taking slow corners.

I really hope they use the car in higher revs, if only for the fact that it is more spectacular for the spectator!!!