Alvyn

iTrader: (1)

how/what would get you a good torque figure from a Cossie engine,

m8's is on greys and 380bhp and he's got 320.2 lbsft

my saff's on greens atm 330bhp and it's got more than that

also WHAT makes speed more torque OR more bhp

Anonymous

You will get a load of peopel saying "torque wins races" now i suspect, but thats not actually the case, its all down to horsepower really.

The thing that accelerates your car is torque at the wheels at the end of the day.

BHP = Torque * RPM / 5252
Torque @ Wheels = Torque @ flywheel / gearing
(subject to transmission losses of course, but those are fairly constant)



So you can see from that basic formula that 500bhp will results in the same torque at the wheels wether you hit 500bhp @ 5000rpm (525.2 lb ft of torque) or at 10,000rpm (262.6 lbft of torque) for the simple reason that the car with less torque and more RPM will have half the gearing at any given speed that the torquier motor will.


There are some other factors, like for example how often you have to change gear and stuff like that, but fundamentally the actuall acceleration at any given speed once you are in the correct gear will be basically the same for any two engines with the same bhp even if one has miles less torque.

The key thing though is that im only talking about at that point in the rev range, generally torquey motors have a flatter curve so the values either side of the peak value will be higher, and therefore quicker over a range of rpm.

Anonymous

ps

Sorry i missed the first half of the question, to get good torque figures you need to have a high VE at that point in the rev range, so having a turbo that is on full boost at the same point as the engine is "on cam" is a good place to start.

M7 COS

Don't diesel cars have higher torque figures?

Anonymous

Yes diesels tend to make more torque, and rev to less RPM, although modern diesels like the new toyota D4D ones etc are starting to get the useable RPM bands up a lot higher, i suspect that in 20 years time diesel engines will be outperforming petrol ones by enough that no one bothers with petrol ones any more if things keep going the way they are at the moment!

Anonymous

Actually it was Colin Chapman that said.
" Horsepower sells cars but Torque wins races" never knew much then .
Rod

Anonymous

Rod, no he didnt then, either that or you are taking the quote out of context and he was talking about "area under the curve" just like i was