Flexible Drives to relocate accesories?

Someone here must have some experience with this subject:

Say I wanted to relocate the typical accessories that are belt driven off the front of the engine to the rear of the vehicle. Maybe for a cleaner look up front or maybe because there is no room up front.

I have seen alternators and AC pumps run off the drive shaft, but they only operate when the car is moving.

Would it be possible to find a flexible drive-shaft that could then be routed to the desired location? Anyone aware of such a shaft that could take the torque of the alternator, AC pump,and PS Pump? A quick search finds lots of stuff for small tools and drives, but nothing for larger torque transmission.

Making too much work for yourself - an Audi Group B car had a hydraulically-driven alternator mounted in the rear. It ran off the same pressure as the PS system.

Also consider that many crank-driven accessories can be electrically-driven - like the PS pump and water pump, off the top of my head.

Here's another idea - can you swap to a transmission of the same model with a PTO shaft?

Thats what I was going to suggest. Take stock of how each accessory likes being driven and mount the whole thing to an electric motor in the spare tire wheel in the trunk. This way the only thing you need up front is a large alternator to keep juice flowing to the motor.

Previas remote mount lots of stuff to the front and power them through a driveshaft coming off of the front of the motor. All of the stuff hang off of one big bracket assembly. Mount a properly sized DC motor where the drive shaft was and you can put that bracket assembly wherever you want.

I was thinking more along the lines of installing a dedicated electric water pump and electric power steering pump. More reliable and easier, but probably heavier and more expensive.

The electric drive is certainly an obvious solution. Not sure if it is as elegant a solution as the flex-shaft though since it involves a stonking huge alternator and an additional electric motor at the scene to drive the accessories. Perhaps if I were starting with a Hybrid drive where the flywheel is already a huge electron producer?

The PTO has the same issue as the drive-shaft in that it wont spin unless the vehicle is moving.

The idea would be to have the front of the engine as uncluttered as possible with all the accessory stuff back where the back-seat used to reside.

Electric water pumps don't require an upgraded alternator and are a performance increase. I'd certainly look into that.

What engine are we talking about?

For a PS pump or water pump, the power draw for an electric accessory isn't much, usually you can use a stock alternator.

NOHOME wrote: The PTO has the same issue as the drive-shaft in that it wont spin unless the vehicle is moving.

Aren't PTOs usually driven by the input side of the transmission, so they spin as long as the clutch is engaged?

My concern about a flexible shaft in this application would be keeping it lubricated under such high RPM's for extended periods of time. I could only see it working if you could tap into the engine oil and send a pressurized feed to the input end with a return line back to the oil pan from the output end.

IMO, the hot-rod market is your friend here. There are many options for compact and clean looking accessory drive brackets for just about any engine you can think of.

Keith Tanner wrote: Electric water pumps don't require an upgraded alternator and are a performance increase. I'd certainly look into that. What engine are we talking about?

Keith:

The application I envision was a tight V8 transplant. But this is really just a blue-sky brainstorm idea that could apply to any project. Esthetics were as much a consideration as space.

I don't think you'll find a flexible drive to be durable enough unless you're building a trailer queen hot rod. If that's the case, then just ditch the alternator and run an electric water pump off the battery.

You could possibly run something off the ring gear on the flywheel to move your bits to the back of the engine. I think you'll end up making a lot of work for very little real benefit.

If you wanted to home-brew a high torque drive cable then look into aircraft spec cabling. The finer wires and increased wire count will help. Also the thicker cables may have counter wound inner to outer strands. The trick would be lubrication and encapsulation.
The NASCAR vehicles all drive the fuel pumps off a similar drive cable, but the torque limit is not high enough for multiple devices. The cable runs from the engine to the trunk area where the pump is next to the fuel cell.

The only belt driven accessory you need is an alternator. Power steering and AC are for sissies, and you can use an electric water pump if needed.

Keith Tanner wrote: I think you'll end up making a lot of work for very little real benefit.

Not for the first or last time

stafford1500 wrote: If you wanted to home-brew a high torque drive cable then look into aircraft spec cabling. The finer wires and increased wire count will help. Also the thicker cables may have counter wound inner to outer strands. The trick would be lubrication and encapsulation. The NASCAR vehicles all drive the fuel pumps off a similar drive cable, but the torque limit is not high enough for multiple devices. The cable runs from the engine to the trunk area where the pump is next to the fuel cell.

NASCAR Cup cars got electric fuel pumps when they went to efi a couple of years ago..

How about the exhaust side of a turbocharger housing driving an alternator instead of an air pump mounted at the rear of the car?

GameboyRMH wrote:

NOHOME wrote: The PTO has the same issue as the drive-shaft in that it wont spin unless the vehicle is moving.

Aren't PTOs usually driven by the input side of the transmission, so they spin as long as the clutch is engaged?

That is correct, otherwise dump truck, car haulers, and other hydraulic driven beds/trailer would only work when moving.

I would think it would be easier to move accessories so they are mounted close to the bottom of the engine rather than at the back of the engine.

That could keep them out of view, and move that weight lower in the vehicle.

In reply to novaderrik:

I would have to think heat is the #1 enemy here.

Its heavy but is there any pto option with this set up?