Horsepower
- Thread starter studlystang921
- Start date
Not necessarily, depends on how whoever tested it out, and how they published the results. I don't believe any manufacturer puts an engine in a car, THEN tests the power. They design the engine, test it on a dyno, etc. That's how they get their figures. It's not like BMW dyno's the new M5 after the car's together, get 507bhp and publish that it only has a 507hp V10.....They are going to publish the highest number they can.
Top HP numbers don't mean shit though unless your car is automatic (meaning it only uses a range of about 2,000 - 3,000 rpm of the rev-range...) But even then, doesn't mean much. I could get someone to burn me a chip with a custom map that only puts out 75 horsepower at 4000 rpm, and then 240hp at 5000... but the car would be incredibly slow even though its' max hp is still fairly high.
Top HP numbers don't mean shit though unless your car is automatic (meaning it only uses a range of about 2,000 - 3,000 rpm of the rev-range...) But even then, doesn't mean much. I could get someone to burn me a chip with a custom map that only puts out 75 horsepower at 4000 rpm, and then 240hp at 5000... but the car would be incredibly slow even though its' max hp is still fairly high.
the hp numbers are from the crank, but can be as conservative or as liberal as the manufac would like.
imo bmw is a bit conservative and infiniti is a bit liberal w/ their numbers.
either that or bmw is more efficient with the powertrain.
(i'm looking at the numbers for 330 vs g35 coupe.)
best way to go is prolly to dyno your car, to get the exact figure on the hp of your car.
Eric, you lost me w/ your last statement. top hp not meaning much and why in the hell woudl anyone make a chip w/ way low hp at one rpm, then get a huge boost? ...
imo bmw is a bit conservative and infiniti is a bit liberal w/ their numbers.
either that or bmw is more efficient with the powertrain.
(i'm looking at the numbers for 330 vs g35 coupe.)
best way to go is prolly to dyno your car, to get the exact figure on the hp of your car.
Eric, you lost me w/ your last statement. top hp not meaning much and why in the hell woudl anyone make a chip w/ way low hp at one rpm, then get a huge boost? ...
it was an example saying that top HP figures do NOT necessarily matter, if the car has a nice and flat torque curve. Even if the car produces 240 hp at a certain rpm, doesnt mean its a fast car if it makes only 50 hp all the other time.
Look at the NSX versus some typical 400hp car... NSX has no problem keeping up even though its max HP is considerably less.
Look at the NSX versus some typical 400hp car... NSX has no problem keeping up even though its max HP is considerably less.
BHP does mean Brake Horse Power, but it has nothing to do with the brakes at the wheels of a car.
It refers to the old, original dyno method of putting a brake drum on the crank of the motor being tested. The brake was applied and a calibrated arm attached to it deflected, then the hp was read off of the scale. Kinda like a beam type torque wrench.
Today it just means that the hp was physically and directly measured, as opposed to calculated.
It refers to the old, original dyno method of putting a brake drum on the crank of the motor being tested. The brake was applied and a calibrated arm attached to it deflected, then the hp was read off of the scale. Kinda like a beam type torque wrench.
Today it just means that the hp was physically and directly measured, as opposed to calculated.
Weight and drivetrain efficiency also affect a car's acceleration. I'm guessing the original poster is wondering why BMW's horsepower numbers seem so low. When magazine racing (racing cars in hypothetical situations based on published horsepower numbers), it looks like BMW's would be slow as crap compared to its competitors. But, looking at the actual 0-60 numbers magazines get, BMWs do quite well. Causes lots of confusions as to what exactly a BMW is putting out.
So basically, a BMW is supposed to get those numbers. Yes they do seem low. No, horsepower isn't the only thing that matters when accelerating. Weight differences btw the cars, suspension setup, and drivetrain efficiency are common things people forget to consider. Also, some manufacturers are more conservative with their published numbers than others. Dyno numbers are out there. The 3 series' most commonly cited competitor (right now) is the G35. Since the actual 0-60s are similar, people try and explain away the huge horsepower difference btw the two. The two most common guesses are either 1) Nissan's drivetrain are horribly inefficient/BMWs are damn efficient or 2) one or both manufacturers are fudging the numbers in one direction or the other.
So basically, a BMW is supposed to get those numbers. Yes they do seem low. No, horsepower isn't the only thing that matters when accelerating. Weight differences btw the cars, suspension setup, and drivetrain efficiency are common things people forget to consider. Also, some manufacturers are more conservative with their published numbers than others. Dyno numbers are out there. The 3 series' most commonly cited competitor (right now) is the G35. Since the actual 0-60s are similar, people try and explain away the huge horsepower difference btw the two. The two most common guesses are either 1) Nissan's drivetrain are horribly inefficient/BMWs are damn efficient or 2) one or both manufacturers are fudging the numbers in one direction or the other.
Gearing is also a huge factor in the acceleration equation.
Here is a great article on the subject that has been posted many times on many forums.
http://www.ls1.com/handt.htm
Here is a great article on the subject that has been posted many times on many forums.
http://www.ls1.com/handt.htm
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It is interesting that BMW's seem to have small hp engines but do have great 0-60 numbers compared to other cars. If I can remember correctly the three series competition does not have a faster car. May be the Mustang GT, but, that is a totally different car. Must be something to do with the torque as indicated above, however I still don't fully understand it. High torgue numbers at high rpms is good do to gearing? Is that how to compare car engines along with hp?
All I know is my 330cic is as fast as my old Bonneville ssei which had a bigger hp engine.
All I know is my 330cic is as fast as my old Bonneville ssei which had a bigger hp engine.
thanks for the article Ryan, i don't get all the details of it, but i think i get it after reading it about 5 more times.. ^^;;
what i still don't get is Eric's example... a car that makes 75 horses at 4000rpm (98.475 lb/ft), and hits 240 hp at 5000 rpm (252.1 lb/ft). must be one hell of a torque curve..
what i still don't get is Eric's example... a car that makes 75 horses at 4000rpm (98.475 lb/ft), and hits 240 hp at 5000 rpm (252.1 lb/ft). must be one hell of a torque curve..
Ugh forget it. Again - all I'm trying to say is that THEORETICALLY if you had an engine that provided like 50 hp all the time except it jumped to 240 hp for the last 200 rpm before redline, even though that 240 hp number is high, the engines torque curve sucks and it won't be a fast car, not as fast as one that provides a very flat torque curve.