Is Power (rwkw) Figure Everything? Why Are People So Hung Up On Kw Figures

[PM-R33]

Think of it this way; probably the easiest way to think of it.

You want a torque curve to hit its maximum torque as early as possible and keep holding that torque without falling off to much as revs climb.

So obviously the best possible torque graph is a near vertical line that then holds flat for as long as possible before it goes down. For reference something like the N45 engine in the twin turbo 335i BMW makes its maximum torque at around 1200rpm. This is why they don't feel like a turbo car with next to no lag but more like a V8 that revs high.

It's all about this maximum "area" enclosed by this torque "curve".

Edited October 25, 2010 by PM-R33

[ARTZ]

ok, guess ill cross that of my list of excuses as well...lol

[PM-R33]

"The only reason I lost was because currently my maximum torque is at around 4000rpm, however next week I'll alter my setup and get it 1500rpm sooner and smoke you fool!"

Hmmm doesn't have the same ring to it as others lol.

[ARTZ]

but see thats where turbos are great, cause if you are in any serious sort of race you usually up over 4000 anyway but if you just want to poke around town they remain nice and subtle down low..

As opposed to aay an angry v8 which can just be a lumpy fuel guzzling bitch to drive around normally..let alone sit in traffic..

Not that i dont like v8s...

[Mandingo]

There are people who strap on big turbos for the sake of saying they have a big turbo, most of the time on a mismatched combo and mismatched application.

Creating peak torque early and sustaining it as long as you can is where its at. Alot of research and trial and error is involved to achieve this, most people either lose interest, settle for what they have or simply run out of money

100% agree.

Its great saying I have X amount of killa watts and all. But area under the curve is where its at.

I want my RB30/26 with 2530s back

Edited October 25, 2010 by Mandingo

[ARTZ]

thats great if you want to tow stuff, but Ive always thought that for racing hp and torque should be reasonably evenly matched so they can work together

Edited October 25, 2010 by Arthur T3

[zebra]

As they say Horsepower sells engines, Torque wins races

[ARTZ]

its also what breaks diffs and gearboxes...

Also if torque is the be all end all, how come a v8 supercar WITH 5-600NM is faster than a xr6t with 1200NM @ 2000

Edited October 25, 2010 by Arthur T3

[PM-R33]

For a fast car you want exactly what I said, torque to hit its maximum as early as possible and to hold flat for as long as possible (for as many rpms as possible).

Vehicles good for towing have a similar characteristic, they reach maximum torque very early in the RPM range, however they don't hold flat for a long rpm and drop off very quickly as revs climb. (Think of a diesel van that loses all power at 3500rpm).

So have a look at this very quick dodgy paint graph I did. In no way is this accurate or based on anything, it's mearly to help understand it all and to get a visualisation. (I swear, if this graph starts an argument....)

You can kind of see a basic relationship of what certain "general" cars have. Obviously every car is different and therefore every torque graph will be different. But the basics still remain similar.

Edited October 25, 2010 by PM-R33

[pistol-pete]

Vehicles good for towing have a similar characteristic, they reach maximum torque very early in the RPM range, however they don't hold flat for a long rpm and drop off very quickly as revs climb. (Think of a diesel van that loses all power at 3500rpm).

exactly why do you think semi's have a million gears

[PM-R33]

Oh I know that is why they have a million gears

[ARTZ]

so i guess electric motors would be the best then?

[Dobz]

kilowatts get bitches..... your welcome!

variable vane turbos are being developed for petrol engines to optimise torque, porsche are already using it with petrol.

Edited October 25, 2010 by Dobz

[N1GTR]

its also what breaks diffs and gearboxes...

Also if torque is the be all end all, how come a v8 supercar WITH 5-600NM is faster than a xr6t with 1200NM @ 2000

Define faster

If you're talking circuit times it would be safe to assume that the reason is that no one has dropped an xr6t motor into a v8 supercab to do back to back tests.

If you're talking drags, it would be safe to assume that v8 supercabs don't give a shit about drag times and the only times they go to drags is for promo. Don't expect them to re engineer the chassis, change to auto, run tubbed wheels etc to get a time that doesn't help them win a championship

[PM-R33]

kilowatts get bitches..... your welcome!

variable vane turbos are being developed for petrol engines to optimise torque, porsche are already using it with petrol.

Variable geometry turbos have actually been out a lot longer than people think.

1989 Shelby was the first production car to use one.

From my understanding the 911 Turbo was the first to use twin variable turbine geometry turbos.

A few cars come out with variable geometry turbos now (mainly turbo diesels).

its also what breaks diffs and gearboxes...

Also if torque is the be all end all, how come a v8 supercar WITH 5-600NM is faster than a xr6t with 1200NM @ 2000

Is there are particular car/test you are reffering to there? Hope you don't think they have 1200Nm at 2000rpm in standard form! (For reference they are around 500-550Nm for a FG XR6T)

Edited October 25, 2010 by PM-R33

[ARTZ]

so hypothetically, if we got the same car set up for drag, we get 2 engine both with the same 650hp output but the 6T has alot more low down torque, first we did runs with the v8 supercar engine,then did runs with the 6T engine, do you think the 6T would be faster?

It thinking both would be pulling maybe mid 10s in a 1500kg+ falcon

[PM-R33]

Hypothetically yes if everything remained the same.

Dyno power graphs would look like this with red line being the V8 Supercar engine in your example

Edited October 25, 2010 by PM-R33

[DCIEVE]

As they say Horsepower sells engines, Torque wins races

Such a misleading statement! The relationship between power, torque & speed is fixed, I'll take the one that creates the greatest tractive effort (force at the wheels) over the operating rev range courtesy of that thing that sits behind the motor.

Edited October 25, 2010 by DCIEVE

[Wacky Dee]

To answer the original question from a relative noob's POV ... (and reiterate what many others have already said) - it's because newbies don't know about response, torque and how that all figures in to the equation.

For example when I first got my skyline I had Toshi tune it on the road as well .. but I too was going for as much peak power although on a slightly less aggressive tune (11.5:1 AFRs) and more boost.

If/when I get the car retuned, I'll probably get an exhaust cam gear, a Nistune and take it to Unigroup to retune on the dyno just for streetability and response. The "195rwkw" I got now means jack shit because I've never taken the car to the race track and the one time I hit 6500+ RPM on the street, I lost my licence for 6 months. So yeah next tune, I'll be using the existing dyno sheets from previous tune as a reference but aim for more torque and power in the low-mid range, disregarding peak power completely. So if I end up with 170rwkw "peak power" but manage to shift the torque/power curve down say 1000 RPM I'll be happy as a pig in mud

[blue_vl_t]

Funny thread....

Example, vl turbo i use to own, Manual box gr30/40 1.06 rear 11.8 @ 118mph, added a 850 hp turbo and went 11.4 @ 126mph, my point being, is that's a 10 sec mph, but be buggered if i could drive it to a 10sec pass, ie. lots more power, lots less usable, especialy on the street, was good fun though.....

food for thought