WRC cars got?

 

300bhp i think, arent they limited??

 

got a 72mm restrictor i think. but just didnt know the bhp and definative answers?

 

32mm restrictor, and that equates to about 300bhp. however, they work hard to reduce frictional losses, and make sure they have as much power as possible available from low down. SO usable power band is huge.

Paul

 

Plus there is no limit to torque, dont they have something like 500ft/lb ??


Andy

 

bhp is pub figures whta you want is torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque torque and in a WRC car is well over 400lb/ft.

BHP shifts cars but torque moves 'em

 

Torque?

Well, maybe they are all using the wrong thing for an engine, because me and my torque wrench can give 600ft-lb.

Yes torque moves you, but torque at the wheels, or to be more precise tractive effort (just the forward force) at the tyres.

But yes, if you assume they hit 300hp as soon as 3000rpm, that's 525ft-lbs of torque.

Not to mention:
Anti-lag to give instant response after gearchange
Very quick gearchanges circa 150ms
High compression ratio (romoured to be as much as 12:1)
Water injection to keep things cool
As big a turbo as possible to get inlet charge as cool as possible
High octane (102 RON) racing fuel
Low drag straght cut gears
Ultra lightweight flywheel, or no flywheel at all

It all adds up.

Paul



[Edited by Pavlo - 1/24/2003 11:43:45 PM]

 

Paul is right re: torque at the wheels being the key. However, applying some theory - Torque at the wheels is (simplistically) engine torque, multiplied by the gear ratio. The lower the gear you are in, the more torque at the wheels for a given flywheel torque. Therefore, to get the optimum torque at the wheels at any given speed, you need max torque in lowest possible gear. Lower gear at a given speed = higher revs. Revs * torque is proportional to bhp, therefore high bhp with correct gear ratio = best torque at the wheels. Therefore bhp is more than just "pub figures", and directly corresponds to maximum acceleration in a given car

This is also why the torque wrench will not get your car up to 60 in 3 seconds - high torque but very low rpm = tiny bhp.

Having said that, peak bhp is of little use compared to a nice wide power band, which the WRC cars will no doubt have. Add that to the fact they're not wasting a third of the torque in the drivetrain or accelerating heavy components, the gear ratios are picked to suit the application, the cars have less weight to carry than road going models. Wheels and flywheel are lighter, they corner much better, brake much better, are driven much better (the single biggest factor in most cases), and it certainly adds up.

 

On a trip round M-Sport I was told that the Focus has just under 400bhp. Its the torque thats the big issue though. I know cos i've been in one

 

chrisp mate - you are all torque!

weava

 

who have you been torquing to

 

At least we wrenched an answer out eventually

 

What the conversion between ft/lb and Nm ?

 

okay time for some answers. They all have 300 BHP, but quite different torque. In order of max torque:

Skoda Octavia WRC
Max power: 300 bhp at 5500 rpm
Max torque: 600 Nm at 3250 rpm

Ford Focus WRC
Max power: 300 bhp at 6500 rpm
Max torque: 550 Nm at 4000 rpm

Citroen Xsara WRC
Max power: 300 bhp at 5500 rpm
Max torque: 540 Nm at 4000 rpm

Peugeot 206 WRC
Max power: 300 bhp at 5250 rpm
Max torque: 535 Nm at 3500 rpm

Hyundai Accent WRC
Max power: 300 bhp at 5200 rpm
Max torque: 530 Nm at 4500 rpm

Impreza WRC
Max power: 300 bhp at 5500 rpm
Max torque: 490 Nm at 4000 rpm

according to http://rally.racing-live.com/en

 

IIRC

1 lbft = 1.355 Nm

 

Cool, thanks.
I just wanted work out what Torgue my PPP sti is meant to have in ft/lb. I make it 300 ft/lb / 401 Nm, right?