History of Petter Solberg`s Xsara WRC...

[Mirek]

Are you sure that you have to use only homologated software, maybe only homologated ECU, I think teams are changing software every rally depending on type of road and conditions!

Yes, I'm sure for S2000.

http://argent.fia.com/web/fia-public.ns ... A%20(09-10)-121208.pdf

Article 5.1.

[Sturla]

http://www.norsk-rally.com/index.php...roen-xsara-wrc

Petter`s new car

[Halvis]

http://www.norsk-rally.com/index.php...roen-xsara-wrc

Petter`s new car

Boring livery, no colours - and where is the msn logo?

[Sturla]

I like it, clean and luxury livery...

[JFL]

MSN logo is on the door Look at the air intake..:"This is my life"

[Micke_VOC]

Great livery... Clean

[OldF]

]Gard: You can't say that one is less important than the other even in WRC because both of them are different ways to say the same. You don't need power curve if You know torque curve and vice versa.

When You get naturaly aspirated engine You have for example peak power at 6500 rpm and peak torque at 3500. The best acceleration You get when You shift at rpm limiter in this case and uses the biggest power and the shortest possible gears. You have to use the biggest possible power area under power curve. That car which has bigger area under power curve in used rpm ratio is stronger.

What moves car is torque on wheels but that depends on gears. And that's what makes many people wrong. Power is still the same and doesn't change by gears (except mechanical losses). For ilustration 250 Nm at 6000 rpm is basicly the same as 500 Nm at 3000 rpm. For the first one You use twice shorter gears and therefore the torque on wheels is same for both.

People started to say that Hp is for top speed and torque for acceleration because of fact that power depends on rpm - the higher rpm the more power unless the torque is going down more than rpm up (when torque is constant, power rises the same way as rpm, when power is constant, torque goes down the same way as rpm up). In the end it doesn't matter if You have 2000 Nm or 200 Nm when You have the same Hp and the same usable power rpm ratio.

The point which makes WRC different is that its power doesn't rise with rpm all the time as in N/A engine. It has restrictor and huge turboboost which creates huge torque at very low rpm. However it still means the same result, the biggest possible power at the rpm ratio we want to use. Because of restrictor torque of WRC has quite short peak and than goes down stadily which makes power almost constant until some rpm when intake looses etc. are groving too much and torque falls even more and power starts falling as well. The biggest possible power area in any graph is when power is constant. Therefore WRC car may have almost constant power in for example 3500-6000 rpm ratio. That allowes using less gears and more shifting mistakes.

That formula You wrote is made from basic physical laws which are teached in basic school

When You multiplied Force by distance s, You get work W = F * s. To get power P from work You have to devide it by time t: P = F * s / t and s/t is velocity v. Therefor the power is P = F * v in linear move. If You get it in circular move it's the same only You change particular values; torque Mt instead of force and angular velocity omega instead of linear velocity. Than the formula looks P = Mt * omega. Angular velocity is omega = 2 * pí * rpm/60. That power is in watts, to have it in Hp You have to devide by tousand to get kilowatt and then multiplied by 1,36 to get Hp. Suma sumarum it gives P (Hp) = Mt (Nm) * 2pí * rpm/60 * 1,36/1000. From that Your simpliffied formula comes

Here with pics from a Mitsubishi Evo9 group N. I believe that the shapes of the curves for a WRC car are similar but with “little” higher values.

Orange=torque; Red=Power; Blue=Power from the wheels.




Rengas teho = power from the wheels
Moottori teho = engine power
Momentti = torque
Nopeus = speed
Ilmapaine = air pressure

Mitsubishi Evo 9 has above 80% (220 hp) of the power between 3100-6100 rpm and above 90% (248 hp) of the power between 3200-5200 rpm.

At 3200 rpm, power = 254, 4 hp / torque = 558,3 Nm (High torque, low revs)
At 4900 rpm, power = 254,9 / torque = 365,3 Nm (Low torque, high revs)

Simplifying the formula P = torque * omega

Omega (1/s) -> angular velocity (1/min) = rpm * 2 * pi / 60 = rpm * 2 * 3,14159 / 60 = rpm * 0,10472

W -> hp (DIN, PS, CV etc.) = 1,36 / 1000 = 0,00136

P = torque (Nm) * rpm * 0,10472 * 0,00136 = torque * rpm * 0,0001424 or P = torque * rpm / 7022

(1 / 0,0001424 = 7022. Calculating in Excel with exact values of pi etc. you get 7023)

Power in DIN, PS, CV etc. and torque in Nm:
P (hp) = T (Nm) * Revs (rpm) * 0,0001424 or P (hp) = T (Nm) * Revs (rpm) / 7023

Power in bhp (British horsepower) and torque in lb/ft:
P (bhp) = T (lb/ft) * Revs (rpm) * 0,0001904 or P (bhp) = T (lb/ft) * Revs (rpm) / 5252

Power in bhp (British horsepower) and torque in Nm:
P (bhp) = T (Nm) * Revs (rpm) * 0,0001404 or P (bhp) = T (Nm) * Revs (rpm) / 7121

Power in kW and torque in Nm:
P (kW) = T (Nm) * Revs (rpm) * 0,0001047 or P (kW) = T (Nm) * Revs (rpm) / 9549

Power in kW and torque in lb/ft:
P (kW) = T (lb/ft) * Revs (rpm) * 0,0001420 or P (kW) = T (lb/ft) * Revs (rpm) / 7043

Mitsubishi evo 9 wheel torques with different gears.


As you can see, the best wheel torque is around the power peak when selecting the gear that gives the highest wheel torque.

Speed (km/h) = (rpm / gear ratio / final drive ratio) * (pi * wheel diameter (m) * 60 / 1000)

Speed with 3rd gear @ 6236 rpm = (6236 / 1,470 / 3,307) * (3,14 * 0,65 * 60 / 1000) = 157 km/h.

[Viking]

Petters team

http://media.aftenposten.no/archive/...pg_960997x.jpg

[OldF]

Also when Hennings Pug almost hit 900Nm, we can asume that the hp figure is somewhat above 300

With 900 Nm torque @ 3000 rpm would mean that the power is P = 900 Nm * 3000 rpm * 0,0001424 = 384,5 hp (DIN, PS etc.)

[morganmilan]

Petters team

http://media.aftenposten.no/archive/...pg_960997x.jpg

Viking, sorry if it´s already published, but, has told Petter any commentary about the car? Will it be the Xsara for the whole season?