8 replies to this topic

[byrkus]

Hello. Today I saw some technical specs about new Peugeot 206 WRC (2003), and it said:

300 HP (221 kW) @ 5250 /min
535 Nm @ 3500 /min

Could this be the fact?? I mean, I thought that rally cars use RPM with much higher values than just 5250 /min (8000 /min came into mind). Is it possible, that a four cylinder 2000 cc engine could produce (eventhough I know there is turbocharger inside)?

And, while speaking of this: could anyone tell me, at which RPM did Group B cars achieve highest power and torque, and how high does values were?

Thank you in advance.

[Hellenic tifosi]

Well, the 300HP figure is obviously not true, as it is only an "official" number. Modern WR cars probably produce more than 360-400HP and a lot of torque. The rev figure you saw is more or less true, as these cars are rarely driven past 6000RPM.

[DoS]

Originally posted by Hellenic tifosi
Well, the 300HP figure is obviously not true, as it is only an "official" number. Modern WR cars probably produce more than 360-400HP and a lot of torque. The rev figure you saw is more or less true, as these cars are rarely driven past 6000RPM.

i have noticed you are a big rally fan, so you sould know this stuff. Still i had the impression that the FIA limits these cars to 300 bhps for safety reasons (after the tragic accidents of the Group B era). I mean don't they put them on the dyno or something after the race ? If they don't these cars could easily produce well in excess of 450 bhp. I mean, i have seen 2000 cc turbocharged engines that produce 450 bhp that are not even racing engines !! And they are very reliable 2 ;)

[Innovator]

All WRC do indeed produce around 300bhp because they breathe through a restrictor. 300bhp is the limit with this size of restrictor.

The drivers do actually want more power because due to the weight the cars actually are not not fast.

John

[Hellenic tifosi]

The 300Hp is a "theoretical" limit, but I am pretty sure that the real value is much higher than that. I have a friend whose father was co-driver at an Impreza '99 spec WRC and he told me that the power is obviously higher than that.

The power-restricting method used nowadays is the inlet restrictor that Innovator mentioned, but in any case it seems that the primary design aim is to have lots of torque at the mid-rpm range.

[Scoots]

The "power" is not obvious from the seat. They probably make between 300-400 bhp ... but because of the restrictions the teams have been focusing on torque and drivability ... and they are definitely torque monsters!

My 1.8 I4 Mazda makes 300lb/ft and 340hp on 91 octane pump gas and a $500 junkyard motor that has never been touched. They could make MASSIVE power, imagine a 1500bhp Focus

I've driven a 540rwhp (Probaby close to 600bhp) Impreza and it was frightening on tarmac

[Jorge Cadete]

Data for the Peugeot 205 T16 evo II

four inline
82 m/m bore
83 m/m stroke
1775 cc
450 hp @ 7600 rpm
56 Kg/m @6200 rpm
8600 rpm Max
3,0 bar boost maximum
216 Km/h @ 8600 rpm in 6th gear
weight - Corsica 86- 945 Kg, without fuel ( 52% FR, 48% RE )

These are the published figures. However, boost pressures and engine set up would vary. One pilot said they had so much power that they tried smaller turbochargers for better response. At Corsica, Michele Mouton utilised an experimental engine said to produce something like 530 hp. The Pikes Peak engine was tuned to produce over 700 hp at sea level.
The other manufacturers involved declared a similar power. However, the Audi engine was said to produce 500/550 hp, the Lancia Delta S4 480 hp and the Ford RS 200 engine 450 hp @ 9000 rpm, for the last Group B RAC rally. In rallycross guise all these engines produced well over 600 hp.
Today cars don't produce so much power, but have a lot of torque at low rpm, and much better response.

[byrkus]

Thanks Jorge!!

450 hp on 945 kg car??! Unbelievable...

[BRG]

The key point is the 34(?)mm air restrictor. With such a limited supply of air, it is not possible to get high revs (you will find a similar situation in F3 where a restrictor is also mandatory). So engineers have concentrated on getting the best torque, the broadest spread of power and the best throttle response (minimising the turbo lag).

Comparing the restricted WRC to the effectively unlimited Gp B engines is illuminating. It highlights just how much progress has been made in 20 years, especially in the electronic engine management field. WRCs probably produce, as others have suggested , anything up to 400bhp which compares surprisingly well to the Gp B despite the restrictor. This, along with the huge advances in programmeable active transmission technology, explains why WRCs are able to beat the stage times set by the Gp B cars, despite disadvantageous power and weight figures.