Understanding torque

S

solekeeper

Member
Location
South Fla.
Guys, lately i've been doing alot of reading turbo/sc's etc etc.. And since I'm looking into getting e46M3 soon, I've been on their site.. And I've been looking at their sc/turbo output numbers... And one thing I seem to noticed was that, one a few stats I read the cars are being outfitted with tons of Horsepower, but a lack of torque... I mean I saw one dyno chart that said 4--hp and 275lb of torque.. Our FX has 270lb's of torque if I remember correctly.. So I'm wondering how this can be?
And also when exactly does torque come into play in a flat drag race?

Sorry if this is confusing, but hope someone can chime in..
 
It's a BMW, that's what they do. The 335i is an exception though, but it also has two turbos under the hood.
M5: 500 hp, 384 lb-ft -116
M6: 500 hp, 380 lb-ft -120
E46 M3: 333 hp, 262 lb-ft (kinda like Will's HP!) -71
E92 M3: 414 hp, 295 lb-ft -119
 
From what I understand, torque gets you moving from a stop, and horsepower keeps you pulling at high speeds. No problem with the stats, I had to back up my claim. I always remembered they had high HP and low torque, but I wanted to make sure it wasn't just the M5/6.
 
Ok, so perhaps (Let's just say) LOL
we had car A and car B
Car A had 100000000 hp with 240lb of torque..
While car B (FX) lol, had 280 HP with 270lb of torque.....If we started from a dead stop, my car would take off faster? Only to soon be left by car A?

This is assuming that both cars weigh the same and both have the same RWD configuration btw.
I have another scenario, but one at a time.. lol
 
It's really hard to say, because that would never happen. But hypothetically, assuming the exact same torque curve, but car B had a fairly consistent +30, it would be quicker off the line.
 
True. Thanks!
Ok proposition B.

Both car's again, same weight and HP, this time different drivetrain.
A has FWD and B (FX) again, has RWD.
Does torque play favorites for either one to take off first?
 
When you get on it from a stop with a FWD car, the wheels loose traction and the steering wheel shakes back and forth. If you don't hold the wheel, it can sometimes actually drive left or right from it.
 
ahh, make sense.

What about the AWD proposal? Does torque favor that over RWD? I'm assuming it doesn't because it has to send torque to all 4 wheels instead of 2, thus causing the RWD to take off a bit better, correct? Once again, assuming all variable are the same.. weight etc..
 
StuLax18 said:
When you get on it from a stop with a FWD car, the wheels loose traction and the steering wheel shakes back and forth. If you don't hold the wheel, it can sometimes actually drive left or right from it.
Click to expand...

A great example of this is my wife's MINI Cooper S. :laugh:
 
solekeeper said:
ahh, make sense.

What about the AWD proposal? Does torque favor that over RWD? I'm assuming it doesn't because it has to send torque to all 4 wheels instead of 2, thus causing the RWD to take off a bit better, correct? Once again, assuming all variable are the same.. weight etc..
Click to expand...

The AWD will launch better.

Cal Speedway 03-08-08 :: Dr.2K vs. Psiclne _Round 2_03-08-08 video by pscdoc - Photobucket@@AMEPARAM@@http://vid9.photobucket.com/player.swf?file=http://vid9.photobucket.com/albums/a89/pscdoc/Cal%20Speedway%2003-08-08/Dr2KvsPsiclne_Round2_03-08-08.flv@@AMEPARAM@@vid9@@AMEPARAM@@9@@AMEPARAM@@a89/pscdoc/Cal%20Speedway%2003-08-08/Dr2KvsPsiclne_Round2_03-08-08
 
Last edited by a moderator:
Here is comparison of S/C FX vs. E46M3

FXtion Vs. M3

345whp 297lb-ft

Look at 60' and 330' and then at 1/8mile he got me.

Quartermiles-1.jpg
 

Attachments

  • Quartermiles-1.jpg
    Quartermiles-1.jpg
    25.1 KB · Views: 46
Torque is a measurement of force while horsepower is a measurement of work based on this force (torque) over distance and time. Because it is only a calculation and not actually measured you'll notice that on every dyno graph the horsepower line and the torque line cross at 5252.

If you have a high torque peak and there isn't much before that then it's really not going to help you "get out of the hole," and if you do have a ton of torque down low then there may not be much available in the upper RPM to "keep you going."

Relating horsepower/torque output, different drive configurations, and which one will win in a race is purely hypothetical as there are many more variables that have to be accounted for.

So when somebody installs a mod on their car that "loses torque" but "picks up horsepower" what has really happened is that the torque band has shifter to a higher RPM and the increase in horsepower (again, a calculation from torque) reflects this.
 
You must log in or register to reply here.
Back
Top