[Tambohamilton]

Steam engines produce maximum torque at 0rpm. Funny, but impractical.

My point is that torque is only meaningful at 0mph. After that power defines how fast you can accelerate, etc. Power itself is defined by torque and rpm, so it's not like torque ever leaves the picture, but power is what's important. My 330d makes 370ftlb...but only 230hp, so it's 'slow'.

Which leads me on to my answer which is 230hp is plenty, so long as handling feels good.

[freakystyly]

TQ has to do with power delivery more than anything, a rotary vs a diesel with the same horsepower will feel very different.

[Tambohamilton]

No; power has to do with power delivery. Torque has to do with torque delivery. RPM links them, and that's it.

[freakystyly]

Ya I get that it's a function of HP. I'll have to research more into it for my own knowledge

[Tambohamilton]

One engine produces 500ftlb exactly between 1000-2000rpm. It is geared so that 1000rpm is 40mph.
Another produces 250ftlb exactly between 2000-4000rpm. It is geared so that 2000rpm is 40mph.
And another produces 125ftlb exactly between 4000-8000rpm. It is geared so that 4000rpm is 40mph.

All other things being equal (grip, weight, drag, losses, etc), which one will go from 40-80mph fastest?




A. They all do it in identical times, because their POWER output is the same (at proportionate points in rpm). More specifically, the 'area under the curve' is the same.

P.S. Sorry, going OT on the torque thing. I'll get back in my box now...

[adc100]

Originally Posted by freakystyly

Ya I get that it's a function of HP. I'll have to research more into it for my own knowledge

Fair enough. And as mentioned torque is only one part of the total picture. The other part is the rpm. And don't get confused by the 5252 number its just to make the units come out to HP.

Now one thing. If an engine does not (with its gear ratio) produce enough HP to get the car moving or to start moving very slow that is another matter. It can be analyzed but isn't worth the time. Didn't mean to belittle you. I have the highest respect for some who admits they might be wrong..seriously.

[adc100]

Originally Posted by BMWILUVU

Did you actually read where I wrote "For street legal-speed driving"?

You are still wrong-period...unless your street is in a field with a tractor plowing. But even there you would be wrong..bc it takes HP to plow not torque.

[BMWILUVU]

Originally Posted by adc100

You are still wrong-period...unless your street is in a field with a tractor plowing. But even there you would be wrong..bc it takes HP to plow not torque.

I doubt you know the difference.

[Tambohamilton]

Originally Posted by BMWILUVU

I doubt you know the difference.

Even if he doesn't know, he's still right on this one!

[BMWILUVU]

Originally Posted by Tambohamilton

Even if he doesn't know, he's still right on this one!

Both of you need to learn more about torque and horsepower.

[Tambohamilton]

Such as...?

[Shatter]

Horsepowers are like sex, way too much is just about enough.

[New2Roundel]

Originally Posted by Tambohamilton

Steam engines produce maximum torque at 0rpm. Funny, but impractical.

My point is that torque is only meaningful at 0mph. After that power defines how fast you can accelerate, etc. Power itself is defined by torque and rpm, so it's not like torque ever leaves the picture, but power is what's important. My 330d makes 370ftlb...but only 230hp, so it's 'slow'.

Which leads me on to my answer which is 230hp is plenty, so long as handling feels good.

This isn't 100% accurate though. HP may dictate the rate acceleration, but you feel torque. I've driven an e90 335d and it felt fast as hell. Pulled like a freight train. I have an e92 M3 which has way less torque but way more power. Yeah, the M3 is much faster from a stop watch perspective, but the 335d felt much faster---particularly under 4k rpms.

There's a very old saying in US which is relevant here: HP wins races, but torque sells cars. So from a real life perspective, I would say that torque can be much more important than hp, since most people aren't out there "winning races".

[Moflow]

Originally Posted by New2Roundel

This isn't 100% accurate though. HP may dictate the rate acceleration, but you feel torque. I've driven an e90 335d and it felt fast as hell. Pulled like a freight train. I have an e92 M3 which has way less torque but way more power. Yeah, the M3 is much faster from a stop watch perspective, but the 335d felt much faster---particularly under 4k rpms.

There's a very old saying in US which is relevant here: HP wins races, but torque sells cars. So from a real life perspective, I would say that torque can be much more important than hp, since most people aren't out there "winning races".

Technically, you're still kinda feeling the power. But practically speaking, lets not be obtuse. You are of course right, for all intents and purposes.

My favorite power/torque quote comes from (I think) an AMG boss in the 90's who said that "people buy power, but people drive torque"

That said, some of the most fun cars ever made had tiny amounts of torque for their power rating.

[New2Roundel]

Originally Posted by Moflow

My favorite power/torque quote comes from (I think) an AMG boss in the 90's who said that "people buy power, but people drive torque"

That said, some of the most fun cars ever made had tiny amounts of torque for their power rating.

I think both aspects can be fun though. I love the dual nature of the S65---you have to be committed to get the car to feel fast. Otherwise it kind of feels pedestrian. Which is nice when you're intentionally trying to drive sedately or intentionally trying to drive fast. OTOH, the 6.4L motor in the Jeep is just hellacious fun because it always feels like it's ready to go. You don't need to rev it up to wake it up.

[Jerain]

Originally Posted by New2Roundel

This isn't 100% accurate though. HP may dictate the rate acceleration, but you feel torque. I've driven an e90 335d and it felt fast as hell. Pulled like a freight train. I have an e92 M3 which has way less torque but way more power. Yeah, the M3 is much faster from a stop watch perspective, but the 335d felt much faster---particularly under 4k rpms.

There's a very old saying in US which is relevant here: HP wins races, but torque sells cars. So from a real life perspective, I would say that torque can be much more important than hp, since most people aren't out there "winning races".

You mean HP sells cars but torque wins races. Also as example if you compare dyno sheets, a FBO N54 has a lot more hp and torque than an E92 M3 troughout the whole revrange, it is faster.

[Tambohamilton]

Originally Posted by New2Roundel

This isn't 100% accurate though. HP may dictate the rate acceleration, but you feel torque. I've driven an e90 335d and it felt fast as hell. Pulled like a freight train. I have an e92 M3 which has way less torque but way more power. Yeah, the M3 is much faster from a stop watch perspective, but the 335d felt much faster---particularly under 4k rpms.

There's a very old saying in US which is relevant here: HP wins races, but torque sells cars. So from a real life perspective, I would say that torque can be much more important than hp, since most people aren't out there "winning races".

No, you can't feel torque. You feel acceleration (regardless of what causes it), and like you say, HP defines acceleration. If a slower car felt faster, you just need to recalibrate your butt dyno.

For example, if you were to engage the clutch (press the gas, in an auto) while holding the brake, at a standstill, the engine would be applying a lot of torque to the drivetrain, but 0 power would be applied to the wheels (no energy dissipated/transferred by them)...and you wouldn't feel anything, other than hear or feel in vibration that the engine was straining.

[New2Roundel]

Originally Posted by Jerain

You mean HP sells cars but torque wins races. Also as example if you compare dyno sheets, a FBO N54 has a lot more hp and torque than an E92 M3 troughout the whole revrange, it is faster.

And adding a supercharger to the S65 will be faster than a bolt-on N54. What's your point? And no, hp actually wins races.

Originally Posted by Tambohamilton

No, you can't feel torque. You feel acceleration (regardless of what causes it), and like you say, HP defines acceleration. If a slower car felt faster, you just need to recalibrate your butt dyno.

For example, if you were to engage the clutch (press the gas, in an auto) while holding the brake, at a standstill, the engine would be applying a lot of torque to the drivetrain, but 0 power would be applied to the wheels (no energy dissipated/transferred by them)...and you wouldn't feel anything, other than hear or feel in vibration that the engine was straining.

You're all sorts of confused friend. Your example doesn't demonstrate what you think it does. Lol.

[SpeedyDad]

I think the E39 M5 proves that 400 hp for a 4,000lb sedan is the sweet spot as long as it’s an engaging car to drive. BMW has never topped the E39. For a 3,000lb sports car, the NSX and S2000 show us that 250-300 hp is plenty to have a lot of fun with. Once you get to 300 hp in a sports car, you have enough power for the car to feel fast. It really comes down to the handling, steering, braking, and overall feel.

[Biginboca]

Originally Posted by SpeedyDad

I think the E39 M5 proves that 400 hp for a 4,000lb sedan is the sweet spot as long as it’s an engaging car to drive. BMW has never topped the E39. For a 3,000lb sports car, the NSX and S2000 show us that 250-300 hp is plenty to have a lot of fun with. Once you get to 300 hp in a sports car, you have enough power for the car to feel fast. It really comes down to the handling, steering, braking, and overall feel.

I agree with this, but it’s basically restating what some other posters said earlier. In laymen’s terms 10lbs/hp is about right. Then add in a few other sensual factors and you can seriously up the fun...

*Manual Transmission
*Hydraulic Steering with good feel/feedback (Maybe there’s a electric rack that’s good too).
*Great Sounding Exhaust Note

The cars you named specifically fill these criteria as do a few other legends like e46m3 etc. These are the makings of a terrific daily IMO.

And it has to be reliable as well of course!

[Torquey]

Originally Posted by New2Roundel

I currently have 3 performance cars at my disposal: A heavily modded Corrado VR6 with about 250hp...

Just curious how you got the stock 178hp Corrado VR6 to 250... unless you added a blower. I have had 4 of them in the past and that is the car that got me "into cars"... so much fun!!

On topic... my 370/370 naturally aspirated 550i seems plenty for me, especially coupled with the manual. By 3rd gear I am already breaking speed limit in most instances. To me throttle response, willingness to rev and good intake/ exhaust notes are just as important if not more than out and out power.

[dr.omid.fahim]

Originally Posted by GenXer

What is the reasonable amount of power to propel a 3000 pound sedan to 60MPH (100KPH)?

200HP, 500HP, 1000HP ?

Response time of
5 seconds, 3 seconds, 1 second?

I know it's probably a blasphemy in a BMW enthusiat forum to say that acceleration time does not matter in the real world. Everyone is limited by law and traffic. Yet most vehicles are measured by their response time instead of how practical or efficient they are or how enjoyable they are to drive.

That being said, my 440i xdrive is a lot more enjoyable to drive than my C7 Corvette. It's a lot slower but it's more forgiving, more predictable, less delicate and much roomier. The C7 tried to kill me once or twice and it almost succeeded one time.
I never have to worry about bad roads or bottoming out in a 440i. I know they're not in the same league but people cross shop for vehicles in the same price range all the time.

Isn't it about time for a more practical matrix to measure performance than just power?

always a bimmer unless u chose a porshe 911 over it wihich will punish u with the haresher ride & harder seats intolerable post 2 hours