| Honda has come up with the most amazing | | | | cornering |
| 4-wheel-drive system, not for off-roaders but | | | | |
| to improve the handling and stability of fast | | | | The side-to-side variation in power is used |
| cars. It is being used first in the new Acura | | | | to improve cornering power and stability. For |
| RL (Honda Legend). | | | | example, when you accelerate through a |
| | | | corner, extra power through the outer rear |
| Why is it so advanced? This SH-AWD system has | | | | wheel counteracts understeer, letting the car |
| the potential to increase cornering power and | | | | corner on rails. In fact, stability control |
| cornering safety by leaps and bounds. It will | | | | systems used on many cars now do this by |
| be ideal for supercars as well as luxury | | | | reducing the amount of torque sent to the |
| coupes.(More information about supercars at | | | | inner wheel – this means that you |
| ) | | | | actually corner slower than you could do. |
| | | | SH-AWD lets you corner faster. |
| First, it allows the amount of power sent to | | | | |
| the wheels to be varied from 30% front and | | | | On the over-run, you don't need that, and |
| 70% rear to 70% front and 30% rear. True, | | | | less power is sent through the outer wheel |
| some other systems get near that, but this | | | | for optimum stability. But that isn't enough |
| allows the system to adjust itself to | | | | because when a car corners, the outer wheels |
| completely different conditions. On top of | | | | have to travel further than the inner ones |
| that, it can alter the torque from zero to | | | | – by 5-10% on very tight corners, so |
| 100% to the left or right rear wheel. | | | | the outer wheel normally goes slower. |
| | | | |
| In other words, all the power can one to the | | | | Honda overcomes this with some gears in the |
| right wheel one minute, and if necessary can | | | | back axle gear set which actually drive the |
| be reversed so that all the power goes to the | | | | outer wheel faster when cornering! This |
| other wheel in an instant. This might be | | | | improves maneuverability and cornering at low |
| needed in slushy or snowy conditions, where | | | | speeds. |
| there was a patch of bare road for a bit on | | | | |
| one side offering good grip, but a bit later | | | | Electro-magnetic multi-plate clutches |
| on a bare patch on the other side. | | | | |
| | | | All this is accomplished by multi-plate |
| In addition to those features, the outer rear | | | | clutches operated electro-magnetically |
| wheel can be speeded up so that it goes | | | | – a world first – and the gear |
| faster than the inside wheel! All done | | | | clutch set used for acceleration. In fact, |
| continuously depending on conditions. A few | | | | these gears also serve as the rear |
| years ago this would have considered | | | | differential. |
| desirable, but science fiction. | | | | |
| | | | An advantage of the electro-magnetic clutches |
| More power to the rear wheel for acceleration | | | | is that the electronic controller does not |
| | | | need to control a hydraulic actuation system |
| Confused? Well, let's start with the | | | | as used normally but an electric actuator |
| front-to-rear power. When you accelerate, the | | | | – this reduces cost and weight. |
| weight of the car is thrown on to the back | | | | |
| wheels by the force of acceleration, so you | | | | Is this the best thing since sliced bread? |
| want more power to go to the back wheels | | | | For the person who wants to have stability |
| – if it all goes to the front you get | | | | and control, and doesn't want to know what is |
| wheelspin. When cornering, you generally want | | | | happening to the car -yes. Such a system is |
| as much or more power to the rear wheels. | | | | bound to reduce the input the driver gets |
| SH-AWD does that. | | | | from the road. |
| | | | |
| On the other hand, when you are cruising | | | | He will be less aware of whether the surface |
| along, you want more power to the front | | | | is slippery, or whether the car is |
| wheels as this increases stability. SH-AWD | | | | understeering more than usual because the |
| also does that. | | | | SH-AWD system is correcting things all the |
| | | | time. |
| More power to outer rear wheel for better | | | | |