BMW's and torque?

The point is you dont say at what rpm the "more torque" is occuring.

An engine can have a wider spread of torque. It can have lots of low down torque. It can have a lot of torque at high rpm like a two stroke.]

The point is that a "torquey engine" tell you nothing. It might be good from 2 to 3 thousand. It might be good from 2 to 9 thousand! It might be good from 5k upwards.

Torque IS power!

opportuinity

Agreed, but I was making general comments, regarding a very general quote.

Indeed - and I'm not disputing that.

My point simply was that the quote - which I now understand was regarding drag racing - doesn't have the same resonance for "racing" as most people in the UK may perceive.

From a driving perspective, a healthy torque curve provides a very drivable, flexible engine.

However, the ultimate in racing isn't predisposed to having a flexible, easy-to-drive engine. The area under the curve doesn't seem to be their main interest - numerous F1 drivers have commented about the relative "torquey-ness" of an F1 engine. That tends to be why they are difficult to drive at low speeds, and (ignoring electronic jiggery-pokery) relatively easy to stall.

I only commented regarding the comment about torque winning races and horsepower selling cars - at least for F1 it doesn't seem hugely relative. The engines that _are_ renowned for their good spread of torque hardly leads them to be the class of the field, even if having a competitive aero package and identical tyres. It makes them good off the line, and able to drive out of corners well.

What wins races in F1 (other things being equal) from an engine perspective, is an engine that produces competitive - hopefully leading, peak power - and doesn't lunch itself. Because unless the track is quite specific, the engines with reputedly pleasing torque curves, don't have much way of capitalising. In F1, passing tends to happen: 1) at the start (which admittedly) the Renaults seem very good at) 2) during pitstops 3) at the end of long straights that lead on to slow-ish corners

There's only one of those scenarios that would likely benefit _specifically_ the rumoured characteristics of the Renault F1 engine. And you only have to see what they try and do to get that last bit of performance - up the rev limit, or have a button that temporarily elevates it. The situations where having a flexible engine, with a wide torque curve, only really make a difference at the start of a race, or perhaps allows them to be able to defend their positions by getting a good drive out of a corner, so the faster driver doesn't get as much chance of slipstreaming to pass.

All I'm saying - and I'm not disputing any of the things you mention - is that the quote mentioned is largely irrelevant in the pinnacle* of racing, today. All other things being equal (ie aero, tyres, reliability), it's the peak horsepower that's winning races.

• I realise some people will find that ironic, because it's a rare treat when there's much actual on-track overtaking in F1 races ;-)

What would be your definition of healthy? Because torque can be measured at all rpms of course. So one that starts high and falls as revs rise like a harley is "percieved" as healthy?

Because some similar sized engines have more torque EVERYWHERE in the rev range including well past the rpm limit of that old V twin! But because these make even more torque at higher rpm they are percieved as being rev monsters, or lacking in low down power.

They dont understand power / torque either... They mean "flexibility" rather than torque. They mean very narrow power band. They are refering to a couple of thousand rpm down from peak power being a gutless area as they exit a corner! But thats because resonant exhaust lengths, inlet tract lengths are used to prop up peak power rpm. When they get out of this resonant area these tuned lengths work against the motor. If they slow rpm further still then harmonics of this tuning prop up different areas of the rpm band,

In drag racing its 5000bhp + engines that win races. Power is torque, the difference is that you have x rpm to see the power. Good power at low to medium revs is the same thing. So why torquey rather than powerful? Unless you say torquey at x rpm then it just means the same as power.

Watch moto GP for close exiting racing!

Torque has nothing to do with rpm? Bring rpm into the equation and it magics into BHP.

No it doesent have to. You can measure torque directly. Without rpm and roadspeed (gearing) its pretty meaningless.

You press the pedal at 2000 rpm what you feel is torque at 2000 rpm Do the same at 5000 rpm and you feel the torque as acceleration on your back at 5000 rpm.

You can have less or more torque at both 2 or 5 thousand revs.

So again their is no such thing as a torquey motor unless you define the rpm and range to which you are refering.

...as moderated via geartrain...

MmmmHmmm...

Area under the curve and/or the range between ~50% peak torque and ~75% peak power past peak power is what counts...

...and a third gear that suits. :)

Area is a good guide. But if most of it is in the 1 to 3000 revs then its drives good in town, but is no faster when you open it up!

Unless... You have the same torque curve that continues at the same peak level all the way to the limiter.

Now you have same torque as before but HUGE top end power. This motor would be called a peaky rev monster! Because power would keep climbing with rpm until rev limiter stops play.

But its just the same torquey motor as before. Only now its not seen as such because it has an incredible top end rush! This is why people think diesels are "torque" when in reality they have no rpm range and make bugger all power especially when revved!

Its not the bottom end torque that people like but the lack of top end torque / power. Very weird!

The ALPINA (all caps, always) D3:

A "good revving" ends about 4250.

Nice, but I have no plans to replace my B10 V8 with one.

As the owner of a proper V8 that grunts from 1700-6100 I get the drift.

My power curve is flattish near the top, so torque is decaying slowly...

Earlier I mentioned two very different BMW V8s

M60 4.0l 286bhp @ 5800, 295lb ft @ 5100

M62 4.4l 286bhp @ 5700, 310lb ft @ 3900

The M60 is a rev monster, compared to the M62, and a stump puller compared to most other things.

I think the 4.0 BMW M60 is a truly great motor, even for the lardy E38

Whereas B-road blasting with an M60 needs 2nd and 3rd, you just stick the M62 in 3rd and go faster.

With the exception of the BMW/ALPINA sequential bi-turbo diesels have either a big powerband or a big specific output but not both.

It's getting all the available grunt w'out downshifting I think - most motors never get beyond half way to the red paint.