Frank Weber is the Chevy Volt vehicle line executive. I had a chance to sit down with him for some discussion while he was in New York at a recent event.
How is the mule development going?
The big step was when we finalized the mules vehicles at the end of August and delivered those on time at the end of August. These are the Cruze-mules using production-intent components. We wondered how they will behave, is there anything that we have not predicted? But so far as surprising as it is for us internally, we have not found anything that is fundamentally flawed.
You stumble over a hundred small development items, software talking to each other, and functions having to be clearly defined, and triggering points, etc, but there is no fundamental flaw that cannot be developed out of the system in the next two years.
So I say there is a lot of work still, but nothing that will prevent the promise of 2010. We still have development to do, and I don’t know what I don’t know, but at this point, I am confident.
So those production intent parts hadn’t existed before in a vehicle?
We had component tests, individually 6 months before those components went into vehicles. But there is always a difference from when you have a component in isolation to when you put them all together in a vehicle.
So is every component that will go into the final Volt, known, understood and finally engineered?
Finely engineered has different meanings for different people. The design since we are going into the development and validation phase it means that we’ll do adjustments, but we have currently for 80-90% of the vehicle, the component designs are available. These are then the in going components into our mule vehicles.
The next stage of our prototypes called integration vehicles, they are real prototypes, exterior, interior, everything. This is coming next summer. So we are currently working on the designs for those integration vehicle next summer, and when you look at that and you count backwards it means you have to have components in May, and to tool them a couple of months, so it means by January we have to have all the components designs and everything available and finalized.
So you don’t have enough time to observe the Cruze-mules much prior to that next stage?
We have some feedback. You have some learning from these Cruze mule vehicles to finally then finalize these designs and say here we have to do a software tweak or here we have to do some adjustments. There is some learning, but not extensive learning. In a traditional program you would probably test those mule cars for a year or two, but we said we have enough experience to develop this car in such a sort time scale. That is the risk element. We have always said this will be a high speed project and we’ve always openly said we are sharing the risk involved.
Do you oversee the assembly of the mules?
Yes. The mules are built at the tech center. It is a mini assembly plant we call our "prototype build operations." There you see them as the engine and powertrain are loaded into them. We have already tested the equipment, how you do the battery loading in the plant. When you look at the process, you have two marriages. In the assembly plant when the power cube is loaded into the car its called a marriage. In the Volt we have two marriages, the power cube and the battery.
Because we have never loaded batteries from underneath so we wanted to see that process . We had guys from manufacturing engineering came in that had equipment to test to lift 400 pounds with precision and the tolerance is very small. Its on a moving plate, it guides itself into position. and then is bolted into the underbody structure. I would say we now have a very robust process on how the battery assembly will work. What the tech time is, etc.
Are the battery packs also finalized?
We have frozen the design for the integration vehicles for next summer. Not only the external design of the packs but all of the internal components. The cooling system, electronics, the frames, the modules.
The software and the software functionality is defined. But what we call the calibration is still development work. What is the temperature band? When do you cool, when do you heat? All of those things need to be calibrated. This is why we need two winters and two summers on the development work. Basically the software is on the platform. The real development work is on the trigger points. The temperature outside needs to be known, the battery temperature needs to be known. Many many things need to be known.