Login






BMW Garage  BMW Meets  Register  Search  Today's Posts  Mark Forums Read 

BMW 3Series (E90 E92) Forum
>
Choose Torue or HP?


05032007, 11:47 PM  #1 
Lieutenant Colonel
66
Rep 1,517
Posts
Drives: E92 335i coupe Black AUTO
Join Date: Apr 2007
Location: Alhambra, CA

Choose Torue or HP?
If you want to race your car for 1/4 or 1/8 mile you want torque. If you want to cruise or do track or circus, you want HP. Torque = quick launch. HP = Long Drive endurance. anyone wanna make a comment on that?

05042007, 12:06 AM  #3 
******
288
Rep 6,164
Posts 
I would trade my Torque for more HP anyday...we don't have wide enough tires to use all of the torque right now so it's pretty useless...
Flip it around, i'd take 380HP and 330tq as opposed to vice versa...
__________________
MKIV 6spd 1000hp Club 
Appreciate
0

05042007, 12:21 AM  #7 
Colonel
101
Rep 2,415
Posts
Drives: E92 335i
Join Date: Dec 2006
Location: Alhambra, CA

I live around where you live. Have you sign in to our socal e92 owner list? The link is in my sig.

Appreciate
0

05042007, 12:27 AM  #8 
Lieutenant Colonel
66
Rep 1,517
Posts
Drives: E92 335i coupe Black AUTO
Join Date: Apr 2007
Location: Alhambra, CA


Appreciate
0

05042007, 12:28 AM  #9 
Lieutenant Colonel
66
Rep 1,517
Posts
Drives: E92 335i coupe Black AUTO
Join Date: Apr 2007
Location: Alhambra, CA


Appreciate
0

05042007, 01:02 AM  #10  
Captain
18
Rep 762
Posts 
Quote:
A good example are those 335i's that got 1st and 4th at the 12hr Bathurst race w/PROcede's in them. 

Appreciate
0

05042007, 03:44 AM  #11  
Banned
13
Rep 1,137
Posts 
Quote:
Bathurst cars were running Procede map giving max torque at around 2000 rpm. I would like to have seen the smooth and silent win without the extra noisy tones of 3000  7000 rpm. Basically people racing their cars should put something under the throttle so that they do not happen to press pedal to the metal by accident and flip the rev range to max hp range instead of max torque. 

Appreciate
0

05042007, 03:48 AM  #12  
Captain
18
Rep 816
Posts 
Quote:


Appreciate
0

05042007, 03:55 AM  #13 
Banned
13
Rep 1,137
Posts 
The average hp numbers you employ, determines the performance. Technically it is the integral of hp under the employed rev range.
When people say torque matters, one can agree with them as far as they mean that the hp curve stays up for a reasonably wide rev range and from early enough. E.g F1 cars have a lot of hp, but very little torque. That's an extreme example but from that we can understand that using revs well beyond 20 000 one is able to turn the max hp into maximum torque at the wheels by using appropriate gear. 
Appreciate
0

05042007, 05:02 AM  #15  
Banned
13
Rep 1,137
Posts 
Quote:
So basically you cannot avoid having them both, except by either employing low revs when you have a lot of torque, but not much power, or high revs, when you have a lot of power, but less torque. 

Appreciate
0

05042007, 05:16 AM  #16 
Private First Class
5
Rep 170
Posts
Drives: BMW F31 330D MSport
Join Date: Feb 2006
Location: Belgium

horsepower equals torque (in ftpounds) times RPM divided by 5250,
so a high revving engine with low torque can still have a high max HP. For example my 320D has 440NM = 324lbs/ft, but since it's a diesel and doesn't rev higher than 4750RPM, it only has 205HP. (yes it's chipped) The 330i makes 255 hp at 6600 rpm, with only 220 lbft of torque (looked that one up) I like lots of torque, really kicks you in the back
__________________

Appreciate
0

05042007, 05:58 AM  #17 
Banned
13
Rep 1,137
Posts 
It is the hp that kicks you in the back. You have much more hp in low rpm than 330. At low speeds the hp advantage that diesels have at low rpm feels so great, because the absolute acceleration in G's is high.
060mph 330 is faster though, since in max acceleration, top hp rev range is used. 
Appreciate
0

05042007, 06:07 AM  #18  
Major General
140
Rep 9,216
Posts 
Quote:
Torque is the rotational force which turns the wheels. Acceleration is greatest when wheel torque is greatest. Horsepower is a function of torque which takes into account time .. in engines time = rpm. So HP is a measure of torque and the rpm at which it occurs. If a vehicle has high HP and low torque it is likely to have a relatively high revving engine. These sort of cars need to be worked hard to ensure that the engine stays in the powerband. Cars with high torque and low hp are likely to be powerful low revving engines, like diesels and old v8's. To consider 1/4 mile performance you have to look at gearing. Strong levels of torque at high rpm (i.e. high horsepower) are seriously useful because this torque can be geared down and effectively multiplied to produce LOT's of wheel torque in low gears. Your statement would probably be true of a vehicle with only one gear. However it would not apply as a rule of thumb to a vehicle with gears.
__________________


Appreciate
0

05042007, 08:16 AM  #19 
171
Rep 6,510
Posts 
TQ and HP are always the same at 5252 RPM
HP = TQ*RPM / 5252 TQ can be described as the engine being able to maintain high power output at lower RPMS... HP can be described as the engine being able to maintain high power output at higher RPMS... But either way, the numbers are just calculated from eachother, so technically you want both numbers to be high for the best power band, and a nice flat output curve... high HP cars with low torque numbers require high engine speeds, and have a smaller powerband, and high torque engines with lower HP have a smaller powerband. short story... you want both! 
Appreciate
0

05042007, 08:23 AM  #20 
Expert Road Racer
28
Rep 1,329
Posts 
I raced an 85 TQ, 110 HP TL1000 versus a 65 TQ, 115HP GSXR750 in a long series of straight line races. Similar total weight, the TL being a torquey twin and the GSXR being a rev monster. We did 080, 1/4th, 1/2 miles, 1 mile and a bunch of rollons.
Almost without exception, the GSXR won the races. The only exception was a 6th gear pull from 4080...we were about even. This also dovetails with my pro road racing experience, where torquey twins were almost always outclassed by their 4cyl class equivalents. Twins do well in World Superbike, but they are also given a weight advantage... I'll take HP. Though power under the curve is the best measure, it is hard to quantify. 
Appreciate
0

05042007, 08:33 AM  #21  
Captain
11
Rep 751
Posts 
Quote:
Unfortunately, the 335 i leans toward the former with the small fast spooling turbos, which is why it doesn't compete better with the near super cars. 

Appreciate
0

Bookmarks 
Thread Tools  Search this Thread 

