Torque figures- Leon FR TDi

[siwel]

It's difficult subject you're right, which one is more important to performance etc. If you have two cars with 200bhp say and the same weight, gearing driven the same, both petrol cars with the same rev range etc etc but the first car had 150lb/ft and the 2nd had 300lb/ft of torque, the 2nd on the whole would win. And if the course involved any decent hills etc the 2nd would pull quite nicely away from the 1st one as the torque comes in when something is opposing it, in the case of a hill gravity.

The above example I have experience with as it's something I've tried, my previous car had 290bhp and 320lb/ft of torque and my friend had the same car with 280bhp and 260lb/ft of torque. Mine had a fair amount of engine mods, bigger bore, thicker head gasket to change the compression ratios, high lift cams, knife edged crank and so on. As mine was running the same boost as my friends on the same turbo I was only making 10 bhp more than him but a fair bit more torque.

And on a drive down through france and around some of the le mans circuit on the flat straights I had a little edge but really not much in it, soon as we hit any hills I started to pull away at a resonable rate.

 

[Red Rum]

Imagine torque as a lever lifting bricks. The bigger the lever, the easier it is to lift the bricks, ie the more torque, the easier it is on the engine to gain its full potential - bhp

Please correct me if im wrong.

 

[siwel]

that's a nice way of thinking about it.

 

[Red Rum]

Glad it actually makes sense to other people lol is was about to make a exit to avoid a ing

 

[OLDOILER]

I'd imagine the scoob has far more torque than the civic but yet couldn't pull - so thats my point really, the torque isn't the main issue, its the power to weight. I think both the WRX and Type-r have similar power to weight ratios.

Power TO Weight says it ALL, the minimum power to get to 100mph is 45HP in a suitable aerodynamic profile - not taking into account the time to get there! [Data from my old Abarth tuning days]

 

[simonrh]

Not trying to be a smart arse but I have to disagree with Siwel comments about torque at the wheels and like for like comparisons.

"Sadly torque is not multiplied by gears (it'd be great if it was) nor is there any difference between the torque at the engine and at the wheels (that'd be bhp)"
---Multiplying and dividing torque is exactly what a gearbox does and hence it controls how much torque is at the wheels. If you need more torque at the wheels then you have to select a lower gear. Wheel Revs drop, wheel torque goes up, power stays the same (revs x Torque=power). A gearbox can't multiply power but can multiply torque (2 rpm x 50nm torque is the same power as 50rpm x 2nm torque). Think landrover in low range as an extreme case. Masses of twisting torque to get up steep slopes but no revs at the wheels hence flat out at 4MPH. Tie 2 identical vehicles together put 1 in 1st gear and 1 in fifth gear and try to drive off in opposite directions and the car in 1st wins. Same power at the wheels, much more torque due to the gearing.

"If you have two cars with 200bhp say and the same weight, gearing driven the same, both petrol cars with the same rev range etc etc but the first car had 150lb/ft and the 2nd had 300lb/ft of torque"
---This is a physical impossibility. If the cars have the same power and the same revs then they have the also must have the same torque. If you multiply 200BHP by (say) 5750 revs then you will always get the same amount of torque(revs x torque=power). This is why it is technically incorrect to talk about engines as having lots of low down torque or lots of top end power. If it has low down torque then it must have low down power too (it will be less obvious on a power graph as you are multiplying the torque by a smaller number of RPM). Increasing torque at a given RPM increases power too. Japanese car engines (like Civic type r etc) with high rpm limits use the otherside of the equation to make their power. Torque may be no lower than competitiors at a given engine speed but they can spin faster and so can make more power. Bike engines are an extreme case. With a sports 600 pulling 16000 RPM now they make no more torque than a 10 year old 600 but spin 50% faster and so make much more power. A 1000cc sports bike might be making 170 BHP at 14000 RPM but it is only making 117nm of torque. Tie it to the bumper of a TDI FR (350Nm?) and the seat will always win.

Torque says how hard can you twist the driveshaft and hence the wheels
Power says how fast can you turn the driveshaft while still twsiting them that hard.

 

[Lewis_FR]

I have to agree the Civic would most definately beat the FR in a straight line. To be honest, my GTi-6 would beat my FR in all situations i believe. But it was such a bitch to get to go fast. No just lightly pressing your right foot down and a big turbo winding up to push you along, instead CONSTANT gear changes to keep the torque available. The TDI FR is a far better all-rounder, whilst only losing a bit of pace. But then it does feel faster, so everyones a winner

 

[chrisboyle999]

may i suggest looking at this link HERE, which explains it all in straightforward english.

 

[BanziBarn]

So to sum up.

Performance is down to power to weight.

Power is down to how much torque the car has and how high it can rev. This ties in with what I thought.