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Bhp used by reverse gearbox?
limpetminer - 16/11/16 at 09:10 AM

How much power does a quaife reverse gearbox use on a typical 1000 cc bec? been told its 30 bhp which seems like a lot.

loggyboy - 16/11/16 at 09:30 AM

Would be percentage not an exact figure - ie if you put 30 bhp in it wouldnt give 0 out.

Website states its 'straight through' to minimise power loss. I suspect its a fairly minimal loss. So any major losses would only be when its in reverse.

[Edited on 16-11-16 by loggyboy]

AdamR20 - 16/11/16 at 03:05 PM

A friend of mine dynoed a 6bhp loss on an R1.

loggyboy - 16/11/16 at 03:38 PM

quote:
Originally posted by AdamR20
A friend of mine dynoed a 6bhp loss on an R1.
]
What were the 2 max power figures?

Andy B - 16/11/16 at 04:14 PM

In our experience you can expect between 6 and 12 bhp depending on the condition of the box. For some strange reason the box is direct drive in reverse which makes it far smoother and more efficient when going backwards.
Regards
Andy

loggyboy - 16/11/16 at 04:46 PM

quote:
Originally posted by Andy B
In our experience you can expect between 6 and 12 bhp depending on the condition of the box. For some strange reason the box is direct drive in reverse which makes it far smoother and more efficient when going backwards.
Regards
Andy


That contradicts there website - have they revised the design?
: https://shop.quaife.co.uk/quaife-reversing-box

AdamR20 - 16/11/16 at 05:37 PM

quote:
Originally posted by loggyboy
quote:
Originally posted by AdamR20
A friend of mine dynoed a 6bhp loss on an R1.
]
What were the 2 max power figures?


Not certain exactly, and if that was wheels or estimated fly, but I think it was a 2007 engine that had a few tweaks so was up around 180-190bhp or so.

ReMan - 16/11/16 at 07:01 PM

Wow 30hp!
But even 6 sounds a lot!
Assuming the MNR is similar there's not a lot of resistance by hand. I'd expect to take some and worse so at higher revs, but 6 still seems a lot

loggyboy - 16/11/16 at 07:59 PM

quote:
Originally posted by ReMan
Wow 30hp!
But even 6 sounds a lot!
Assuming the MNR is similar there's not a lot of resistance by hand. I'd expect to take some and worse so at higher revs, but 6 still seems a lot

Its not just about resistance, although that is the root cause, as energy can never be lost, only transfered, things like heat and noise are where the energy 'goes'.

MikeRJ - 17/11/16 at 10:58 AM

quote:
Originally posted by Andy B
For some strange reason the box is direct drive in reverse which makes it far smoother and more efficient when going backwards.
Regards
Andy


If it was direct drive, then the output shaft would not be reversed, literally by definition. Was this maybe a case of having the wrong diff or something and requiring a reverse to get forward motion?

garyo - 18/11/16 at 11:06 AM

quote:

If it was direct drive, then the output shaft would not be reversed, literally by definition. Was this maybe a case of having the wrong diff or something and requiring a reverse to get forward motion?


A Jap engine spinning the wrong way??