Acceleration

[Alfettaman12]

With my Prelude past 600 miles and the oil changed, I tried an acceleration run today. Dry conditions, 18 deg.C, gentle breeze, Sport mode, S+ off.

0-60mph took 6.9 seconds, but I think I should have brake-torqued it for a little bit longer before releasing the brake. Also, the HV battery was only showing about 30% charge, so it will be interesting to see whether a more fully charged battery gives a better result. This launch mode is clearly programmed into the power train, because the petrol engine went straight to full power and stayed there - with no synthetic gear changes. Launch the car normally (just by flooring the accelerator without brake-torquing) and the gear changes are evident.

Not too bad for a first attempt and certainly quicker than the 8.2 seconds that Honda (very conservatively) claim. The internet seems to have fixated on this 8.2 sec figure, and most reviewers don't seem to know how to launch the Prelude correctly anyway...

 

[PR76UDE12]

Shouldn't be surprising to anyone paying attention. It's a slipperier civic for the purpose of such things so should at least match it. The gears/no-gears thing seems to be kinda like you've said, though it's more that if you're rolling at all it triggers the 'fake gears'. Try it with brake hold on, curious to see if that triggers it or not. Odd that they don't really document it anywhere. But also doubly odd that Honda logged their official time using S+, why give people ammo to complain? If anything the most baffling thing about this car is the way it was presented. It's not really a CVT, and it's not a 8.2s car either, it's far better on both points.

 

[Alfettaman12]

Shouldn't be surprising to anyone paying attention. It's a slipperier civic for the purpose of such things so should at least match it. The gears/no-gears thing seems to be kinda like you've said, though it's more that if you're rolling at all it triggers the 'fake gears'. Try it with brake hold on, curious to see if that triggers it or not. Odd that they don't really document it anywhere. But also doubly odd that Honda logged their official time using S+, why give people ammo to complain? If anything the most baffling thing about this car is the way it was presented. It's not really a CVT, and it's not a 8.2s car either, it's far better on both points.

Yes, I'll try launching from a brake-hold stop and see if it does the 'fake gears' thing.

A family friend (and fellow petrolhead) works for a big insurance company and I asked him why Honda would publish such a pessimistic 0-60 time. He said that some manufacturers do this with completely new car models, in the hope of lowering the initial 'risk premium'. Later on, when the insurers have got some real accident data and claims statistics, premiums can be more accurately based on those and less on the published performance data.

But, as you say (and whatever the reason), it plays right into the hands of most reviewers, journalists, nay-sayers and armchair test pilots...

 

[Alfettaman12]

....and perhaps there is some honesty with the 8.2s 0-60mph time, because significantly faster times are only available if you know how to configure the car correctly (Sport on, S+ off, brake-torquing).

 

[PR76UDE12]

Thinking about it I don't reckon brake-torquing will make any difference? At least in theory it shouldn't, with the electric motor doing all the work with instant torque etc... Sounds like you need to do some more launches, for science.

 

[Alfettaman12]

Thinking about it I don't reckon brake-torquing will make any difference? At least in theory it shouldn't, with the electric motor doing all the work with instant torque etc... Sounds like you need to do some more launches, for science.

I think the drive motor in our cars is a permanent magnet synchronous motor. If so, it is technically possible to control the zero-speed torque (to hold the rotor stationary against an external force or resistance) by managing the current in the stator.

Theoretically this could create extra rotational energy when the external load (in our case, the brakes) is suddenly removed. But I have no idea if the Prelude's drive motor is managed in this way.

As you say, more testing required...