But let’s just for a moment take the time to observe just how much weight has been taken out of the car.
From the rear it looks like it’s jumping the ramp!
In case you’re wondering, the answer is 350kg. The exhaust alone weighed 50kg! Anyway on with the build…
So we’ll be using an AC motor adaptor from our partners at www.canev.com connected to the original gearbox.
We should be able to drive the car in second or third gear from standstill all the way up to freeway speeds – this is because the motor is incredibly torquey and can run at up to 10,000 RPM, no dramas.
The car will also have a creep mode so once a gear has selected, it will creep forward just like an automatic car.
Clutch? Well strictly speaking, where we’re going we won’t need a clutch but if gear changes are required, then a clutch will obviously make it easier – so we’ll be fitting one.
With the motor and clutch connected it’s time to mate the assembly to the gearbox. Already it’s looking good! Amazingly this little motor will make more torque and power than the outgoing petrol engine.
The motor although relatively light at 50kg still needs an engine hoist to mount it. The pictures make this look easy but it really wasn’t. It’s very much a concentrated dead weight which is awkward to maneuver especially when trying locate it onto a gearbox spline. The end results are positive though and a major milestone for the build. We’re able to turn the motor with one hand which then turns the wheels. A beautiful moment!
It’s amazing that such a small and simple motor can replace the ridiculousness of an internal combustion engine with all its meters, valves, belts, filters, lubricants, ECUs and pistons flapping all over the place.
In contrast, the motor looks like it always belonged in there! Where should everything go?
Component placement is crucial with this sort of project. It’s obviously important all components find a home in the car, even though such a vehicle was never designed to house things like a motor controller or a DC DC converter. Irrespective of this, the principles go a little something like this:
Each component must be close to its relative neighbour eg controller near to the motor
Overall placement must not upset the original balance of the car. If we can improve the balance then better still
No component can be mounted via bolts or welds to any part of the chassis – otherwise the car will be rendered unroadworthy
Must be good ventilation for all the bits that tend to get hot
Must be accessible and easily maintainable, for example, it’s no good having the batteries tucked under the floor without a means to measure or maintain them
Audi and other manufacturers clearly spend billions on their packaging to make sure everything fits just so and they have had the benefit of designing a car around said components.
In our case and as we’ve said previously, there is a plan around component placement. However, until everything is in we won’t know if we need to do a any re-work as per the points above.
With the motor mounted it’s fabrication time OR time to start cooking meth. Judging by the safety kit it really could go either way 😉
All the components have been chosen such that they should technically work and complement each other. But that doesn’t mean they’re going to mount easily under the bonnet. Most of the original ICE components (alternator, power steering pump, aircon pump etc) attached to the engine so there aren’t even any old brackets we can leverage off.
Our philosophy with this sort of project is that everything should be done once, done properly and not jerry rigged. I’ve seen so many builds where things have been lashed together just to achieve ‘movement’ only to pull it all apart again to be mounted properly.
We already know these components are fully operational so we may as well work on getting the install right first time.
Make no mistake, fabrication is a major component of any EV build (even if you buy a kit) as most components don’t have brackets to suit the target car.
The (electric) power steering pump is a good example.. It’s technically superb and a perfect match for the car. But the mounting brackets that came with it don’t work in the chosen location and as a result we end up taking a full day to make new ones to suit.
However, this flavour of creativity is satisfying like you wouldn’t believe! Perhaps not for all though.
Battery Pack No1
In particular, we know the battery boxes will take up to 60% of the effort. The Lithium batteries despite being lighter than sealed lead acid, are still heavy and need to be secured from both lateral and vertical movement. Not an easy task when we aren’t allowed to drill or weld into anything structural. Fortunately in most cases we find suitable chassis pickup points for everything.
The pack at the front you see here represents a third of the planned battery capacity. We’ve already taken the time to bottom balance all cells and are fully charged ready to go. The rest of the cells will mounted towards the rear of the car nice and low.
A heap of research is required to make sure we can quickly tap into the Audi’s loom and integrate into the CANBUS. We make liberal use of cheat sheets and pre-prepared ‘designs on a page’ so we can simply connect/execute while in the workshop. That way we’re able to be as efficient as possible while on the shop floor and make short work of some of the more complex work.
Integration is key. If we didn’t have to integrate with the rest of the car then this build would be soo much easier. The car’s ECUs need to be placated or ‘stubbed’ as it’s called in software development, otherwise we’ll have errors on the dash and unexpected behaviours elsewhere. This video shows we’ve been successful!
So everything up front has installed well and even looks good too! There’s a bit of tidying to do especially around the excess loom but that will be trimmed and tidied away at the end.
Next steps will be the routing of the high voltage cable, connecting up of the first battery pack and installation of the contactor box.
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