pas & alt driven@ rear diff

[here2learn]

just come across this


apparently used in the touring cars for better weight distribution

what are the pros and cons of this

[Acidburn]

con's if your not driving no psp and no charge to the battery.

[Acidburn]

Also be better off running them off the prop rather than rear driveshafts, less movement going over bumps etc.

[Error404]

that is off the prop there is pulley on the front of the pinion shaft

[terrybullwon]

Yep thats a A4 or late 80 touring car.

Race car only

[here2learn]

from this one 1 of 5 from 1991

[terrybullwon]

http://www.s2forum.com/forum/showthread.php?t=21012&highlight=Alternator

[Acidburn]

Do an electric psp like some other forum members that way you don't have to worry about belts etc.

[here2learn]

my question is if electric psp were available why would audi choose this set up

what benefits are there over an electric pump other than an excessive drain from a racing battery

[Acidburn]

probably wasn't around at the time.

weight saving on the lines going to-from the rack, less chance of breaking it and a leak.
you can have it setup so the pump draws a minimum power compared to the small drag from the belt on the propshaft.
They weigh less than a stock pump if you get the right one.

[here2learn]

if mounted inside on the bulk head will have still of moved some weight behind the axle

and could still have an oversize battery in the boot with alternator running from the prop

will displace more weight to the rear



just pooling knowledge for now so when time comes can be confident and stop second guessing myself all the time.

[Pat D]

I like the idea of moving the heavy alternator away from the front of the engine. This and an electric power steering pump would be great.

[Error404]

If its a race car you can place an electric PSP wherever you want it, best to use it as a ballast item to help with corner weighting.
Using ally hard pipes the extra weight of relocating it anywhere on the car is not really an issue

Don't think it would be very difficult to machine a pulley to fit over the outer CV joint and make up brackets to mount the alternator alongside the rear diff. As above though, no charge unless you are moving at a reasonable speed.

[Ian Simmonds]

Ray Reid on here (A1 quattro) used a prop driven rear alternator for a whie, but out on stage he had quite a few failures. Its not easy to stop it shedding belts as the prop has pretty harsh rpm changes.

[here2learn]

could be chain driven with some for of gas damper to mount alternator on to absorb minimal movements?