2013 BMW M5 may have more horsepower than reported
09-09-12, 04:23 PM
#18
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09-09-12, 07:31 PM
#19
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But a Veyron has a low center of gravity. The M5 is tall and essentially as high as a 7 series. To call this overweight monstrosity sporty is like calling a hippo manoueverable : Both are fast in a straight line but that's about it.
09-09-12, 11:35 PM
#21
I don't know why a lot of people thinking the 5 drives like the 7. I have a 7 and drove a new 5 for a while. Even though the 5 is based on the 7 platform, the 2 cars drive completely different. The 5 being whole lot more sporty than the 7. Maybe it become softer and less angile than the E60 and E39 ( I had an E39 too ), but saying the 5 now drives just like a 7 is not correct.
09-10-12, 12:23 AM
#22
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I don't know why a lot of people thinking the 5 drives like the 7. I have a 7 and drove a new 5 for a while. Even though the 5 is based on the 7 platform, the 2 cars drive completely different. The 5 being whole lot more sporty than the 7. Maybe it become softer and less angile than the E60 and E39 ( I had an E39 too ), but saying the 5 now drives just like a 7 is not correct.
09-10-12, 04:49 AM
#23
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09-10-12, 09:49 AM
#24
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i always thought the lost of drive train should be a constant number as oppose to a variable (or at very least, not a linear relationship to the crank power). which means a car would lose, say 30 HP to the drive train (30 HP is a lot). so 30 HP to a car with 200 HP is 15%. but 30 to 600HP is only 5%.
i believe the same thing was tossed around when estimate GTR's HP based on wheel power, only to find out GTR was to the spec when you measure the crank power.
i believe the same thing was tossed around when estimate GTR's HP based on wheel power, only to find out GTR was to the spec when you measure the crank power.
09-10-12, 10:00 AM
#25
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For most American driving conditions and preferences, torque, is actually a more significant figure than HP...especially low-RPM torque. It's true that HP plays a role in determing the torque figure (there is a math-formula), but raw HP is gnerally a measure of wind-resistance at high vehicle-speeds (like on the Autobahn), where torque directly measures on the car's ability to accelerate. Most Americans want more torque at lower RPMs for acceleration, and don't necessarily need HP for high-speed cruising..
09-10-12, 12:36 PM
#26
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For most American driving conditions and preferences, torque, is actually a more significant figure than HP...especially low-RPM torque. It's true that HP plays a role in determing the torque figure (there is a math-formula), but raw HP is gnerally a measure of wind-resistance at high vehicle-speeds (like on the Autobahn), where torque directly measures on the car's ability to accelerate. Most Americans want more torque at lower RPMs for acceleration, and don't necessarily need HP for high-speed cruising..
09-10-12, 12:43 PM
#27
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Winner! After turning my Evo over 200-300 times on a real eddy current dyno (Mustang), the variability between runs can be significant depending on factors such as 1) temperatures 2) cooling (fans to simulate actual speed) 3) ECU fuel/ignition timing and the list goes on. If the readings were on a dynojet, it can be skewed somewhat higher so it can be misinterpreted since it is only an inertia loaded dyno without real "street load" on it. Combined if there were no SAE factors for environment variability, you can see significant variation in the readings. The best way to use the figures is for comparative reasons for mods (vs. baseling) or against other cars. You'll then know if that particular dyno is typically overrating or sandbagging the figures.
09-11-12, 08:24 AM
#28
Except that the 15% "rule of thumb" is nonsense and always has been. The "drivetrain loss" does not remain at a fixed percentage as you keep going up and up and up in power. The actual "loss" that you'd see on an inertial rolling load dyno like a dynojet for a car at this power level is probably more along the lines of 10% or less, which would put the car within earshot of its actual power ratings. This is just something for fanboys to get excited and chat about. Notice how on all of these super powerful cars that if you apply the 15% rule to all of them, almost all of them are "under-rated" on power? They're not, or at least not by nearly as much as people claim or would like to think. It's because the 15% rule of thumb is BS.
What goes outside the discussion though is the powerband. The M5's powerband is ridiculous. I've seen a 'Stage 1' ECU upgrade (not sure if piggyback or flash) get released for it with gains of 70whp and 90ft-lbs.