More HP, less torque?
#1
More HP, less torque?
I'm just a bit confused here, the 197 HP rx8 gets 164 lb ft of torque, while the 238 HP version gets only 159 lb ft of torque. How does more HP result in less torque? (maybe I'm not quite understanding what torque is...)
Whatever the case, how could one get more torque outta the 6speed version?
Thanks
Whatever the case, how could one get more torque outta the 6speed version?
Thanks
#3
Don't think of HP as different from Torque. Most people get it wrong this way. What the car really produces is Torque, but what it makes out of running is HP. Even though we have small torque, the RPM the engine makes gives room for higher HP.
HP = (torque x RPM) / 5252
If you can understand that formula, you will understand why we have high HP for such little torque. For example, if our engine can only rev to 5000 RPMs and still makes that 159 lb/ft of torque, we will wind up getting 151 HP only.
By the way, the number that you quoted are Peak number only. It doesn't mean the car runs that kind of power all throughout.
HP = (torque x RPM) / 5252
If you can understand that formula, you will understand why we have high HP for such little torque. For example, if our engine can only rev to 5000 RPMs and still makes that 159 lb/ft of torque, we will wind up getting 151 HP only.
By the way, the number that you quoted are Peak number only. It doesn't mean the car runs that kind of power all throughout.
#4
The automatic may have 5 more pounds of torque at the crank but it probably losses more torque to the wheels than the manual does b/c of additional parasitic loss from the lovely torque converter - so I think whenall is said and done the extra 5 lb/ft that the low power engine makes is probably wasted anyway by the converter. They both probably putdown very similar numbers to the wheels (torque wise) but who knowsfor sure when no one cares to dyno an automatic Rx8?
#5
actually the torque converter doesn't rob torque, the transmission, on the other hand is a different story.
from how stuff works (on torque converters):
in addition to the very important job of allowing your car come to a complete stop without stalling the engine, the torque converter actually gives your car more torque when you accelerate out of a stop. Modern torque converters can multiply the torque of the engine by two to three times. This effect only happens when the engine is turning much faster than the transmission.
To counter this effect, some cars have a torque converter with a lockup clutch. When the two halves of the torque converter get up to speed, this clutch locks them together, eliminating the slippage and improving efficiency.
from how stuff works (on torque converters):
in addition to the very important job of allowing your car come to a complete stop without stalling the engine, the torque converter actually gives your car more torque when you accelerate out of a stop. Modern torque converters can multiply the torque of the engine by two to three times. This effect only happens when the engine is turning much faster than the transmission.
To counter this effect, some cars have a torque converter with a lockup clutch. When the two halves of the torque converter get up to speed, this clutch locks them together, eliminating the slippage and improving efficiency.
#6
If the 6-spd A/T High Power RX-8 is really coming out, then maybe they will have added a lockup clutch with it in order to reach 9000 rpms. Torque converter will not be able to handle that much spin, it will slip. That would be cool especially for those who want the power of the current 6-spd M/T RX-8 without having to shift. Not my cake, but I know a lot of the current A/T owners would take it.
#8
Originally Posted by Xyntax
If the 6-spd A/T High Power RX-8 is really coming out, then maybe they will have added a lockup clutch with it in order to reach 9000 rpms.
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