How Honda's IMA could be improved

I whole heartedly agree, I just saw the unveil of the CRZ and that is a complete and total joke! The specs are horrible and it's plainly stupid. The market that Honda is shooting for wants a sporty hybrid that handles well. I don't think the CRZ cuts it at all. It looks sporty, but specs speak a whole 'nother story.

Here are the facts:
at 2,500 lbs with a 122 hp combined is not moving anywhere fast (I highly doubt it will beat 10 seconds 0-60 )How is that sporty!?!?

EPA Mileage is 35/38 (CVT) 21/36(manual)
Umm isn't that what a civic hybrid does? and with the same 0-60? Unless the CRZ comes in at 15k, it is going to bomb.

it's a two seater, this is up to the buyer's prefs but I'm not into a car that is supposed to be "sporty" and is as fast a prius(I will keep my vast amount of room, and 50mpg).

I've seen Honda dropping the ball alot more than they should in recent years. I don't know whats going on over at Honda, but it seems like a shake up is necessary. They have been pouring all this money into the FCX Clarity and forgetting about what they need to do now, so that they survive to mass produce the Clarity!

 

I agree.
The basic IMA concept does not change since 1999 Insight-I launch.

I don't think so.
The two-motor system requires double battery system, two motors, two drive inverters and so on.
Or, do you think the current one motor IMA system costs only $500 to $1,000?

Ken@Japan

 

Adding a more powerful 2nd MG will prevent it to be air cooled (like current IMA). Liquid cooling the motors and inverter will add cost.

You end up with a very complex car. You'll have the complexity of a non-hybrid with full hybrid components. Since you still have the mechanical gearbox transmission, the benefit of adding a more powerful electric motor is probably beyond the diminishing return.

eCVT in Prius multiplies torque by converting ICE power to electricity. Non-hybrids and IMA does it mechanically with gears or cones. Since eCVT has a totally new concept made only possible by a hybrid of gas and electric, mechanical complexity was simplified. Your proposal add both mechanical and electrical complexity.

Well, that's my though...

 

HCH 0-60 is 12 seconds, about 2 seconds slower than the Prius.

Insight II almost match the Prius in acceleration but fell short in size, refinement, standard equipments and fuel economy (a class lower).

CR-Z may be a fraction of second faster than the Prius. It's size and fuel economy drops further below the Insight.

These are just engineering trade-offs within IMA limitation. A good hybrid design (like HSD) has less limitations and less trade-offs had to be made. If you look at the whole package it shows.

 

I stand corrected! I thought the HCH was faster than that (12.0sec). I can't see this selling (the CR-Z). The orginial CR-X owners are outraged for what Honda is determined to be passed off as sporty. I just looked this up:

The Altima and Fusion hybrids will beat the CR-Z in speed (both have 0-60 times of 7 sec) and have the same (Altima) MPG and better (Fusion) MPG.

I guess it's too "late in the game" to go back to the drawing board and design a new hybrid system. The CR-Z is a joke that even the Honda fans can't get behind.

 

That's a great point about the other full hybrids.

The hope is that with some effort owners will be able to beat the EPA numbers in good weather. We'll have to see about that.

I did not see electric A/C mentioned for the CR-Z. I guess it will be gasoline driven A/C like the Insight II.

 

Prius has 201.6V battery pack while the Insight has 100V. Prius battery can absorb and release energy 3x faster as well. The Prius needs to.... in order to power it at low speed.

The inverter has to be more robust for above reason. Since there are two MGs, one can generate while another consume it. This inverter can no longer be a simple device to convert DC->AC or AC->DC. It also needs to route between the two MGs.

Come to think of it... I don't think IMA has an inverter because it's MG is a DC motor. Since the battery is also DC, there isn't a need for conversion.

 

Insight uses 10kW battery system to drive the single 10kW motor.
Prius uses 27kW battery system to drive MG2.
If your two motor system just uses 10kW motor, you're not required to place the double battery system.
But, does your two motor system use only 10kW motor?

The MG's are driven by each inverters, so Prius has two inverters, one for MG1 and one for MG2.

Ken@Japan

 

The IMA motor/stator is not air cooled. Because it is attached to the engine block at the CVT it is inherently liquid cooled. Airflow benefits are negligible. Besides these details and given its use and construction, the IMA motor does not produce any significant heat patterns that would demand special cooling accommodations.

Cheers;

MSantos

 

While I prefer the design of HSD over IMA, IMA could be improved simply by increasing its power. Higher voltage does this with the least cost increase and without major increases in size and weight. It will cost more but doubling or tripling the electric HP could really help.

 

The IMA system uses an AC synchronous motor. This 3 phase AC synchronous unit often leads many in the press and in the public to assume it is a DC motor stator.
A DC-DC converter is used which then feeds into a Motor Control Module that carefully and precisely meters and modulates the amount of "power" sent to the electric motor.

Because the DC-DC module does not convert DC to AC it is not an inverter as we know in the Prius. Instead, it modulates the DC so that it can drive the motor via its three phases. No step up is involved here as it is in the Prius.

Cheers;

MSantos